After the seeds are dried, where do you store them? In the freezer or room temp dry area (in ziplock)? TIA. Rob
After wrapping them in paper envelopes, put them in an airtight jar, with some powdered milk in an small nylon,etc. or something that will absorb any moisture. Put the jar in the refigerator untill needed. I use the jars with the rubber seals inside and the lock that comes on the top of the jar, although jars with screw type lids will work.
My approach to saving tomato seeds is much more casual. I spreat the seed and pulps in saucers to dry and set up on a shelf in the house (usually high and out of sight). It stays there until January or February wheb my mind goes in search of things to take me away from the gray days of winter in Cincinnati. I remember the dishes of seeds, take them down and wash away the dried gunk and free the seeds. Using a pair of tweezers, I transfer each seed onto a square of toilet tissue about an inch apart. When the square is full, I place another square on top and lightly spray the "sandwich" with water. This seals the seeds inside. When dry, I usually place the paper/seed packets in one of my cannisers (I have a collection of flower/sugar type cannisters) where they stay until I'm ready to plant. At planting time, I cut the sheets of paper into squares and plant the seeds with paper and all. I get nearly 100% germination.
A lot of it depends, Sandy, on how long you intend saving them.
If you are just saving enough for next season, they can stay at room temperature with no hardships. If you want to save them long term, freezing is the best way.
I put my dry tomato seeds up in labeled pill bottles. Each of them then goes into a zipper bag, labeled as to the year. The whole thing then goes into the freezer.
If you do freeze your seed, remember to let it come up to room temperature before opening the container. Otherwise condensation can form, and effect later germination.
Hope this helps.
My method for seed saving works very well. I collect the seeds of whatever vegetable or flower I wish to grow the following year(s). If its tomato, I put them in a sieve and run cold water over them to wash away most of the pectin and fibers. Then I turn the sieve upside down and whack it over a piece of plastic wrap. I allow them to dry out for a week or two. If the seeds are dry or semi-dry to begin with, just dry them on a paper towel for a week or two. Then I put them in paper envelopes. Storing them in a ziplock plastic bag may cause them to rot or to have fungus form (happened to me with squash seeds). Then you can store them in a cool dry place for the winter in an open plastic bag. Or in the refrigerator. The longer you keep the seeds, the less that will germinate.
>. Then I turn the sieve upside down and whack it over a piece of plastic wrap. I don't understand what keeps them from sticking together? Merely rinsing tomato seeds doesn't remove the gel coat.
>Storing them in a ziplock plastic bag may cause them to rot or to have fungus form (happened to me with squash seeds).It's likely that they were not fully dry, and the ziplock became a sauna. Easiest way to test seeds (especially large ones like squash) is to put one on a hard surface and strike it with a hammer. If the seed merely squishes, it's not ready. A fully dried seed will shatter.
>The longer you keep the seeds, the less that will germinate. How long is "longer"? Properly prepared seed, kept frozen, remains viable for as much as 40 years. For short term storage (i.e., to be planted next spring) it almost doesn't matter. Seed stored at room temps will generally not be affected in that time frame, in most locales.
Ideally, you want to avoild heat and moisture. But of the two, moisture is the more deadly. If you keep your seeds dry you should be ok with them for just about any reasonable length of time.
I did not notice anyone mentioning fermenting the seeds. This is really critical since not only does it remove the gel sac (which prevents germination) but it destroys any seed borne disease.
Process is simple. Squeeze the tomato pulp & seeds into a container. Perhaps add a bit of water. Let everything sit in a warmish place until you get mold/scum on top. Usually takes 3-8 days depending on temperature. They are now ready to clean.
Fill the container with water. Wait 10 seconds. The seeds will sink to the bottom. Slowly pour off the water which will take the mold/scum with it. Do this 4-5 times and you will only have clean seeds left. Drain the container (I pour onto a piece of screening), dry the seeds and store however you wish.)
Bill McKay in E. Mass
This is really critical since not only does it remove the gel sac (which prevents germination) but it destroys any seed borne disease.
I guess most of the stuff having to do with seed saving, growth and culture of tomatoes happens in the Tomato Forum here while this place is for finding heirloom varieties of this and that. And that's why I didn't step in and say anything about fermenting or anything else.
But just a few words about what you wrote above.
The gel sac does seem to prevent germination if the seeds drop to the ground in the fall but removal of it isn't critical for germination in a home setting.
Also, fermentation deosn't remove all pathogens, it does lower the burden of pathogens adhered to the exterior of the seed but can't do a thing about those pathogens that are in the endosperm of the seed.
There are some commercial treatments for those, like hot water, that aren't easy to do at home. And I don't think it's worth it anyway becasue the full story isn't in as to which pathogens are in the endosperm re viruses, etc.
Most of the foliage pathogens and Fusarium and Verticillium are known to be on the outside, that's for sure and while fermentation helps lower those, it doesn't remove all of them.
If you rinse the tomato seeds long enough (2-3 minutes) and use your fingers to move them around in the sieve, most of the jel (actually pectin), will dispurse. Sure, a few may stick together, but once they are set on a sheet of plastic wrap to dry, they will usually become a little easier to seperate. Even for that, you can still have two or three seeds that stick together and plant them in a single pot. I usually never plant a single seed in a pot unless I have very few seeds. If freezing tomato seeds actually germinate reliably, then my garden would be totally overrun with tomato plants growing everywhere! I toss bad tomatoes outside the garden and into areas where there are just weeds or nothing growing and rarely have I ever seen a tomato plant sprouting up the next season. As to the length of time that seeds can be kept is variable. Tomato seeds like several others will lose their ability to germinate after two years no matter how they are stored. I have seen seeds that have been commercially packaged and kept at the proper humidity and temperature fail after one year. This is the reason that most companies that supply seeds will stamp the years date on them. I tried to grow several bean, squash and other seeds that my father had stored away for years (since 1970's) in a cool dry dark place, and nothing sprouted.
>Tomato seeds like several others will lose their ability to germinate after two years no matter how they are stored.Sorry, but this statement is totally incorrect. Tomato seed that has been properly gathered, dried, and stored under the right condition, remains viable for from four to ten years depending on variety.
Carolyn Male (who, I'm sure, will speak for herself on this) regularly grows out seed that is ten to 12 years old.
Freezing the seed extends the viability even further; out to at least 40 years. That's precisely how many of the world's seed banks preserve their seed. Based on your contention, the USDA, for instance, would have to grow out its entire collection every two years. Trust me, they have neither the time, the money, the manpower, nor the inclination to do that.
SSE grows out 10% of its seed collection each year. If you were right, that grow-out would have to include half of their tomato accessions each time. That doesn't happen, either.
And let's talk about viability figures for a moment. When a reference says that ABC seed remains viable for X number of years, that does not mean all the seed is dead after that time. Viability figures, which are developed primarily for market growers, mean that after X years, 50% or less of the seed will germinate.
Onion seed is the classic case. In theory it is only viable for one year. I have a friend who, last year, planted onion seed that had been merely laying in a drawer, with no special handling, for more than ten years. She brought in quite a nice crop from that seed.
>If freezing tomato seeds actually germinate reliably, then my garden would be totally overrun with tomato plants growing everywhere! Three factors are at work here. First, the tomato seed you are tossing out still contains the anti-germination compounds found in the gelcoat. Second, the weeds in those areas choke out any that do want to grow. And third, many of the seeds are eaten over the winter by birds and small mammals.
Many people do see volunteer tomatoes, as a matter of fact. Just enough seed coats get weathered away over the winter to allow germination.
Carolyn Male (who, I'm sure, will speak for herself on this) regularly grows out seed that is ten to 12 years old
Hark!! This is Carolyn speaking for herself.(smile)
I routinely store tomato seed for many years and it is true that I and also many others have no problem with germinating such seed that is 10-15 years old. Of course the germination level is down at that point but germination levels of 50% and greater are quite normal with 5-7 yo seed.
Most SSE folks who list lots of varieties grow out their stocks on a rotating basis every five years, and that seems reasonable.
The USDA tomato station at Geneva, NY, like all the other USDA stations, is severely constrained for money and does growouts maybe once every 15 years. That's good, in a way, since it lessens the chances for spontaneous mutations which can occur any time the DNA is replicated in a growing plant or germinating seed.
But the isolation distance for the uSDA is zero, read me, zero, so there's lots of crossed seed there. But since the uSDA is NOT a place for non-researchers to obtain seed, this is not the problem it might be.
I do not dry down my seed with silica gel. I do not store in the freezer. I do not store in the refigerator. I store my seed in stolen ( borrowed) scintillation vials with tight caps and they are stored at ambient temperature.
I have a tomato seed collection of many hundreds of varieties and storing them in a fridge is just not an option and since I've never ever had a variety go south on me I'm happy with my storage routine. The USDA does sotre some stocks in Fort Collins at -40 or -70 but retail seed companies store at just cool temps above freezing, and here I'm talking about the larger retail companies, not the smaller specialty heirloom type companies. Some, like Tomato Growers Supply, do germination tests on seeds they sell, most others do not.
((This is the reason that most companies that supply seeds will stamp the years date on them. I tried to grow several bean, squash and other seeds that my father had stored away for years (since 1970's) in a cool dry dark place, and nothing sprouted.))
The dates stamped on seed packages mean absolutely nothing other than to indicate when the seeds were put in the package. What's more important is when the seeds were harvested and that information is not usually given to the commercial client by the wholesaler. IN most cases the seed packaged is several years old when it is packaged, but this varies from place to place and reflects the seed sources used by the retailers.
Also, with reference to the bean and squash seeds from the 1970's, next time soak those seeds in water overnight, poking them down to hydrate them. If that doesn't work then soak them o/n in 0.2% potassium nitrate or a dilute prep of Miracle Grow or Schultz, etc. For reasons not understood by seed physiologists the nitrate ion seems to awaken old seeds. I have used it successfully to enhance germination of old seeds and to awaken seeds that had zero germination based on the seed quanity I had to play with.
And many folks have germinated cucurbit ( squash) seed that's very old, like 30-40 yo; same with bean seed. it all depends on the conditions those seeds were stored in over the years, whether an earthenware pot in a cave in the SW or a desk drawer in Cheyenne WY. I mention the latter only becasue when the USDA station was moved from Cheyenne to Fort Collins many years ago the record germination of a tomato seed was recorded, and that was about 50 years old, as I recall.
The oldest tomato seeds I awakened were 22 years old, a strain of Abe Lincoln, actually.
It's actually too bad this thread is here and not in the tomato forum where others might well participate. This forum is for locating heirloom varieties and associated issues, not basically for questions about culture, etc., the way I understand it. But it matters not, really.
I have no problem with seed saving questions being here, per se, but also find similar topics in the forums dedicated to specific veggies.
ks, if you were to make a comment that tomato seed is dead after two years and do that in the tomato forum, you would be descended upon by a host of tomato aficonados who would regale you with affidavits to the contrary. (G) As it is you have just Gardenlad and myself to chat with you about what you posted, at least so far.
I do hope our posts have helped you better understand seed longevity, germination inhibitors, etc., and the worth of fermentation, etc.
I will also mention that before I retired and was growing 700-1000 tomato plants/year I'd always dig up 10 of the many volunteers and transplant them to a dedicated area so i could see if I could ID the variety. Most of the time I could but as always, sometimes there were some cross pollinations. But then that's always an opportunity to dehybridize something and see what one might have in order to genetically purify it up, for that's how about 95% of all heirloom tomatoes arose, by natural cross pollination.
Of course today we have all sorts of folks manually creating so called heirlooms. And while some of them are pretty good, my own personal view is that the family type heirlooms are the true heirlooms.
Guess I am wrong? or right? Whatever it is, the forums have many opinions..
From the outside I see that different people have different experience. I've lived in places where tomatoes damn near grew in cracks in the sidewalk, they were like a weed, and others where there was a long list of issues in growing them even on purpose. Clearly there is more complexity involved in growing something than addressing any one issue of it, like seed age, can possibly cover, though seed is a serious discussion of course! -- but since growing from seed covers the seed age, seed storage, seed preparation before storage, seed preparation before growing, seed growing (e.g., tossing in the ground vs. carefully babying it indoors), it looks like it'd be hard to weigh any one aspect of the topic, like seed age, without taking the other variables into consideration.
Assuming the seeds are fully dried, in the freezer in a sealed container is the best place to store them. I use a laboratory sealing wax to reinforce the seal of a jar.
ksrogers...."Tomato seeds like several others will lose their ability to germinate after two years no matter how they are stored"
I am presently growing "Space Tomatoes" flown on the Space Shuttle Challeger in 1984 and left in space for 6 years. all ten seeds have sprouted are now growing very well. oh oh "ATTACK OF THE KILLER TOMATOES"...RUNNNNNNNNNNNN!
Wow! I was doing a search on "tomato seed saving" when I came upon this fascinating thread.
I couldn't recall whether I should 'stir' the fermenting tomato seed mixture or not. I'm still not sure about that but I did learn a heck of a lot about seed longevity and seed saving practices.
As always, Carolyn and Gardenlad, thank you. That was extremely informative and served to varify my experiences with old seeds.
For many years, I kept my seed in the fridge because, 1- I had a small garden and, 2- I hadn't found Gardenweb yet. Now my seed collection is too large to refrigerate any but a few of the more precious ones. I've grown tomato seeds that I purchased 7-8 years ago and had good germination. Last year I grew 3 squash seeds that I purchased from Park's Seed 12 years earlier and all germinated and produced well. I've had similiar experiences with other seeds that were 10-12 years old.
Also, I have lots of volunteer tomatoes this year because I had the space to allow some of the many 1000's of volunteers to grow and....they just looked so darned healthy. Among them are some Amish paste that I was able to identify from last year but some of the plants have tomatoes that are much larger than last years AP and they look different than the pictures in Carolyn's book, so I'm intrigued by these. It'll be fun to see what they're like.
>I couldn't recall whether I should 'stir' the fermenting tomato seed mixture or not. I'm still not sure about that You want the theory or the reality, Peggy?
In theory, seed fermentation is an aneorobic process, and stirring slows it down by introducing oxygen.
However, I stir once a day for two reasons: 1. Because I was taught to do it that way, and habits die hard even when you know better (if you need proof of this, why do you slit an apple pie three times? One slit is for the steam, and the other two are because your momma did it that way); and 2. I notice that if I don't stir I lose quite a few viable seeds that are stuck to the debris and mold floating on the surface. Stirring releases them, and they sink to the bottom.
Re: #1 above, I also add an equal volume of water to the seed mass. Carolyn keeps saying this is unnecessary, and I believe her. But I do it anyway, because that's how I was first taught.
What I'm saying is, so long as you follow the basic process, I don't think there is a whole lot you can do that will screw things up.
Whew, thanks Gardenlad. I did it right!
I know all about those, "because I was taught to do it that way, " habits.
Cause my momma said so!!
I couldn't recall whether I should 'stir' the fermenting tomato seed mixture or not. I'm still not sure about that but I did learn a heck of a lot about seed longevity and seed saving practices
Had just started to do this post when I saw Brook had answered. LOL
I don't stir, ever, b/c fermentation IS an anaerobic process and the additional oxygen introduced doesn't allow for the highest amounts of fermentation end products to form.
And it's the acidic end products that are primarily responsible for destroying any pathogens adhering to the seeds, which is the main reason that one ferments tomato seeds.
Dr Helen ( can't remember her last name) at the Cornell Geneva station has done a lot of work in this area per her grants from Campbell's, as in soup. Campbell's has a large vested interest in their many tomato varieteis of old and newer ones they develop, re seedborne transmission of pathogens.
I had loaned your book to a friend and just had it returned today. I read the part on seed saving again.
The stirrers and the nons, both good points.
HI...I like aka Peggy found this thread by seaching on saving tomato seeds. I just wanted to pass along what I have been doing. All I do is rinse them off by running water over them while in a sieve and then let them dry on something like a paper plate. After a few days, I knock them off the plate and just put them in a regular envelope that I keep on a shelf in my basement. I have been doing this for several years and it seems to work ok for me. I have been saving my "Polish" tomato seeds like this and they keep working even after a couple of years just sitting in an unsealed envelope. I got the original seeds from plants my sister gave me. SHe told me her father-in-law got the original seeds when he went to Poland, so if we want to get more of these tomatoes, we had to keep the seeds. Before I moved to my present house, I put a bunch of seeds in an envelope and forgot about them. About 5 years later in my current house, I ran across the envelope seeds and started them. I got seedlings from about 90% of my seeds. I lost about 1/3 when I was hardening, but I started quite a few, so I had a lot of very healthy plants that year. Every year, I take some of my biggest tomatoes and save the seeds from them. I just add them to my collection of seeds that are left over in my envelope(I dont seperate by year) and those are the seeds that I start the next year. The seeds I start may be last years, or may be from several years ago. Its luck of the draw. This "fermenting", saving in an airtight container, storing in the freezer are all new concepts to me - and it seems like a lot more work than I really need to do. I just wanted to pass along my experiences.
From Carolyn: "...Dr Helen ( can't remember her last name) at the Cornell Geneva station has done a lot of work in this area per her grants from Campbell's, as in soup. Campbell's has a large vested interest in their many tomato varieteis of old and newer ones they develop, re seedborne transmission of pathogens..."
Perhaps her name is Dr Helen Griffith? Could you furnish the name of the paper or the monograph?
This "fermenting", saving in an airtight container, storing in the freezer are all new concepts to me - and it seems like a lot more work than I really need to do. I just wanted to pass along my experiences.
As I state early on in my post on seed saving, as long as you're saving seeds just for your own use there's no need to ferment seeds becasue any seedborne diseases will stay only in your own garden.
But if folks are sharing and trading seeds or offering them through Seed Saver's Exhcnage, for instance, courtesy dictates that you don't also share your tomato diseases for the ones we know are seedborne.
Do join us in the Growing Tomatoes Forum where we do talk about all things tomatoey. (smile)
SEED STORING CONTAINERS? --
I USE SOME OF MY MOM'S OLD DIABETES TEST STRIP CONTAINERS (~ 1" DIAMETER, 3" HIGH -- LIKE OLD FASHIONED BROWNIE 8 SHOT FILM CANISTERS, BEFORE FOIL FILM POUCHES)-- SHE GENERATES ABOUT 1 CONTAINER/WK... KGARDENER
This is related, I swear!
Since you all save seeds, I thought you might be interested in my Heirloom Tomato Swap!
Here is a link that might be useful: Heirloom Tomato Swap!!!
great info..... my first year growing tomatoes, and hopefully my first year saving seeds. I'll hopefully "branch" to heirlooms...
This year I sprouted tomato seeds that date to 1989. They haven't had optimal care either. I used to store the packet in a plastic bag--sometimes sealed, sometimes not--in a shoe box in a kitchen cupboard. I put one of those dessicant packets that come with shoes into the bag. Now they live in a plastic bin under my bed. Aren't seeds wonderfully forgiving things?
Lots of good information in this thread. I might also that the older the seed the longer it will take to germinate. My 2004 Roma seed from Rocky Mountain Seed Company germinated in 3 days, older seed may take 2-3 weeks so be patient.
Store seed in a cool, dry dark place. The freezer is tricky because the seed really needs to be dry. Also, be very careful handling frozen seed because rough handling when frozen can cause the seed to break.
Gibberellic Acid can also help faciliatate germination of older seed. Check out the link below.
Here is a link that might be useful: Gibberellic Acid for Fruit Set and Seed Germination
I have successfully grown tomatoes from seeds that are over 10 years of age. But what I have found most interesting is the amazing ability of a tomato seed to germinate after the most difficult of storage conditions. If any of you ever have an opportunity to acquire composted sewage from your treatment plant ( it usually is at least 10 years old and cities, towns, etc. frequently use it for their own landscaping ) I am certain you will be astounded at the number of tomatoes that germinate. It seems the digestive system don't work on the seeds. Only problem being is you don't have a clue as to the variety untill they grow.
Indeed, a rather informative thread except for one slight error. The fermentation is the result of an aerobic fungal yeast process rather than anaerobic as erroneously stated.
The above is Martin's opinion based on his comments in the thread linked to below.
For a fuller discussion please see the link below where others have also commented. The thread linked to below on this date is still on the first page of the main tomato forum with 53 responses.
Here is a link that might be useful: Saving Seeds Thread from Tomato Forum
Hey! Play nice, you two.
Thanks Carolyn137 I been trying to get these seeds that are my papals that are as old as me (15). I will try that i would love to save some seeds the squash, being a family heirloom.
Martin, you say (in the linked thread) that you "got this information from the acting manager of a local gardening store".... Carolyn's bio, on her GW member page, impresses me just a WEE bit more than that. PhD in microbiology, who literally wrote the book on heirloom tomatoes, vs. temporary retail manager. Gee, that's a tough one.
No offense meant, Martin. I'm a grad student, has been drummed into my brain! LOL.
Hmmm... I've just learned something about posting on GW. The greater than-lesser than signs blank out whatever's between them. That was to read: "I'm a grad student, CONSIDER THE SOURCE has been drummed into my brain!" LLLOL
Carolyn's bio, on her GW member page, impresses me just a WEE bit more than that. PhD in microbiology
Thanks for your confidence in me but as you also read in that link I provided, I don't know what proportions of bacteria, yeasts and molds ( filamentous fungi) might be found in a natural tomato fermentation.
Lots is known about the microbiology of fermented foods such as Yogurt and saurkraut, for instance, but the microbial contributions found in natural fermentations of tomato, cuke and melon seed, for example, I've not read about anywhere.
As I also said in that thread, if there is one person who might know something that would be Dr. Dillard, and perhaps out of sheer curiousity I will contact her. She may even remember me from our two previous chats although that was long ago and the subject matter was confined to pathogen removal by fermentation.
Several years ago my sister sent me seeds from that were being tossed out where she worked. How long she had them I do not know but by the time I planted them they were 10 to 12 years old water and mildew stained packets some labeled 1989. Almost all sprouted at well over 70%. The seeds I collected expanded my collection immensely.
Why don't you ask Mr. Whealy what he thinks of Carolyn Male's expertise?
I'm sorry to tell you, I still have more confidence in her than in you. You have the sort of arrogant attitude that, it seems to me, precludes learning. Since you are sure you know, you are unable to learn; and if you cannot learn, you cannot know. That is why I have so little faith in arrogant experts. When they are the only ones setting themselves up as experts, very little faith diminishes to none at all. (Dr. Male, in contrast, is built up more by others here than by herself).
That's my take on it anyway. I come here to learn, so (starting now) I will skip over your posts. That's all I have to say on the subject. I'm sorry if that's rude. I just don't think I have anything to learn from you.
When making wine, sterile "must" is prepared with added specific strain of yeast. It is placed into sealed containers with an airlock. The conversion of sugars to alcohols and esters is done anaerobically. If the "wine" is exposed to an oxygen source, the result is vinegar, an acid.
A simple way to resolve this might be to measure the alcohol content of fermenting tomato seed and also the change in acidity. I believe there may be some accuracy to the statement that both aerobic and anaerobic processes are at work. The question to ask is how much of each is there?
Anaerobic processes do not necessarily take place in the absence of oxygen. They do not require oxygen to take place. I suspect the first stage of fermentation is anaerobic but that later stages are aerobic. This is based on the conversion of plant sugars to alcohols followed by conversion to acids. Its not a new observation to say that the liquid on fermented tomato seed is much more acid than the original tomato juice.
Thanks Martin. I did actually know that.
I've been giving this a little thought, please note though that I'm a mathematician and not a microbiologist (if that's the correct discipline).
The times that I have fermented tomato seeds, I have had a mat form on the surface. Now, wouldn't that mat inhibit the exchange of gases, in particular, the transfer of oxygen? This would mean that the liquid underneath would quickly use up the dissolved oxygen if there was an aerobic process going on, wouldn't it?. If so, and I think this was suggested somewhere, perhaps there is an aerobic and anaerobic phase. Just a thought. I repeat, I'm not even educated in the relevant discipline. I only studied mathematics and physics at university.
Why store seeds over the winter?
I throw scraps in my flower garden for mulch and the next year I get plenty of tomatos growing like weeds.
Interesting question, McCommas. One that I never gave any thought to. For me it's like asking, why breathe? But, with a little thought, I came up with these:
Some of us grow more than one variety at a time, and want to know what we are planting.
More importantly, many of us are dedicated to preserving heirloom varieties, and to keeping the seed pure for future generations to enjoy.
Some of us grow so many tomato plants (often numbering in the hundreds) that there's no way we could depend on volunteers to meet our needs. I am not, personally, big on growing tomatoes. Even so, I typically put out 12-20 plants.
Some of us don't have flower beds in which to toss our scraps and hope for volunteers.
Some of us run well managed compost piles, in which the seeds are killed by the heat.
Some of us are so particular that _anything_ which appears in a garden that we didn't plant is considered a weed, and promply removed.
I'm sure there are other reasons as well.
It took a while to read up on the mechanism of fermentation and to understand what "could" be taking place when tomato pulp is fermented. Here is what I dug out.
Yeast is capable of both aerobic and anaerobic fermentation. The key differentiator here is that aerobic fermentation is essentially a "base" process (more accurately, it is acid neutral) where sugar is converted to carbon dioxide and water with release of usable binding energy. Anaerobic fermentation is an "acid" process where the end product is C2H5OH plus carbon dioxide.
The reason for primary fermentation with wine is to multiply the amount of yeast in the must. It is NOT intended to produce alcohol though a certain amount of anerobic fermantation takes place at this stage. The secondary stage of winemaking using a sealed container with an airlock is the stage at which the anaerobic process takes place that results in alcohol. Technically, yeast that is undergoing anaerobic fermentation does not reproduce itself. It does not have enough excess energy to do so to any significant extent. The key piece of information here is that primary fermentation does NOT consume all the available sugar. Even secondary anaerobic fermentation may not consume the rest of the sugar since some wines are deliberately made too sweet to start with.
I located a photo showing oxygen diffusion into the surface of a liquid. It very clearly showed that oxygen is highest at the surface and at a depth of 1 inch is essentially gone. This presumes the liquid is NOT stirred. This photo is not online, it is in a plant propagation manual I have. Yeast does consume oxygen if it has a C6H12O6 (sugar) food source. It undergoes aerobic fermentation so far down in the liquid as oxygen can permeate. Since the yeast is consuming the free oxygen down in the liquid, the aerobic fermentation gradually is limited only to very near the surface where free oxygen can still permeate. If you ferment some tomato seed in a glass container you can clearly observe the aerobic fermentation at first down to the bottom of the container then after a few days limited only to the top 1/4 inch or so. There is still some oxygen below that but it is NOT ENOUGH to sustain aerobic fermentation.
The tomato seed and pulp as fresh squeezed from a tomato is acidic. But when it has been fermented for several days, it is much more acidic still. The only way it can get more acidic is if it has been undergoing anaerobic fermentation where the energy cycle results in acetic acid.
There are other organisms in tomato pulp besides natural yeasts but for all practical purposes, they have little effect on the fermentation process.
The conclusions here are really easy to make.
1. Tomato seed should be fermented with the liquid at least 1 inch deep in a container. This leads to the maximum acid production with little or no acidity at the surface but with heavy acid production at the bottom of the container. If you use shallow containers, the reaction will be aerobic which does NOT produce the acidity needed to kill pathogens.
2. The container should not be sealed since some oxygen is required at the surface. If you seal it, you wind up with alcohol instead of acetic acid or you may not get enough yeast multiplication to sustain the anaerobic fermentation.
3. Don't stir on a daily basis. This introduces oxygen which prevents the process that produces the acid. If you do stir, you will still get clean seed but they won't have gotten the "acid" bath needed to remove pathogens.
4. The fermentation process is highly temperature dependent. In general terms, the first 2 days of fermentation at 72 degrees is aerobic. The next 2 days are a combination of aerobic and anaerobic. By the fifth day, aerobic reactions are limited to the surface and everything beneath that is anaerobic. So ferment for at least 5 days at 72 degrees, longer if the temperature is lower.
Martin, You don't really lose this one but your statements are on the wrong track. It is perfectly feasible to ferment tomato seed using an aerobic process by stirring the liquid daily. But the purpose of fermenting seed is to produce the acid which helps sterilize them. As you said, you can't dispute the laws of physics, etc. Go back to a biology textbook and see where acetic acid comes from.
Fusion - who is now returning his 3 containers of fermentation experiments and his litmus paper to storage where they belong. I did learn a lot from this though!
One thing I forgot to add to the above. The conversion of alcohol to acetic acid is done by bacteria in the presence of oxygen. The balance here is that the yeasts exhaust their energy source and slow down multiplying but then the bacteria kick in and convert the alcohols to acetic acid. This is a relatively slow process compared to the active fermentation of the yeasts.
You are incorrect about bacteria converting alcohol to acetic acid. Read here.
the overall reaction is CH3CH2OH + O2 into acetic acid plus water induced by the presence of specific types of bateria metabolizing alcohol and oxygen. There are bacteria that are both alcohol tolerant and capable of metabolizing alcohol to obtain energy. One of the keys to any chemical reaction is to follow the energy. Its kind of funny but plants use sunlight as an energy pump to convert carbon dioxide plus water to sugar. Then yeast converts the sugar to alcohol anaerobically extracting part of the energy. Then bacteria convert the alcohol to acetic acid and extract a little more of the stored energy. The alternative aerobic reaction is for yeast to convert the sugar immediately back into carbon dioxide and water.
You are keying in on saying that there is no anaerobic fermentation process. I would agree that tomato fermentation is not a purely anaerobic process. I would also have to state that it is not purely aerobic either. There are anaerobic and aerobic components which I did my best to document above.
If you ferment tomato seed, you can easily smell the alcohol (yes I know that alcohol is essentially odorless but when I smell it the hairs in my nose curl up) between the 3rd and 5th days. The Alcohol disappears over the next few days, some from evaporation and some from conversion to acetic acid. When I tested the acidity of fermenting tomato seed on the fifth day, it was over 1 point more acid than the original tomato juice on day one. You can't get increased acidity without anaerobic fermentation of sugar to alcohol and then conversion of the alcohol to acetic acid. Remember that aerobic fermentation is a "base" process as in NO acid.
Its pretty obvious that there "should be" both aerobic and anaerobic components to fermenting tomato seed. You can force a pure aerobic reaction by stirring the pulp. You can force a pure anaerobic reaction by sealing it so oxygen can't get in. The correct method uses both processes.
I invite you to find a single place on the web or in any other documentation that states it is a purely aerobic reaction.
You are correct that it would be possible to just mix in a little vinegar with the pulp to increase the acidity. I'd rather just let the acid form naturally. I still treat all of my seed with a dilute bleach solution just to be sure I've gotten rid of all the pathogens I can.
I located a photo showing oxygen diffusion into the surface of a liquid. It very clearly showed that oxygen is highest at the surface and at a depth of 1 inch is essentially gone. This presumes the liquid is NOT stirred.
Fusion, thank you for this info, and if possible, might you be able to take a pic of that photo to show here? I know that it might affect the quality somewhat (taking a pic of a pic) but I thought it was particulary interesting that oxygen levels an inch below the surface are so reduced!
Some of that is way way off base.
Water is made of hydrogen and oxygen but they are bonded together in such a way that a large energy input is required to separate them. When I speak of oxygen permeating the water, that refers specifically to free oxygen which is NOT bonded to hydrogen. Typically the free oxygen is a very small percentage of the overall water volume.
The problem you are not addressing is that the yeasts in the liquid rapidly use up all of the free oxygen in aerobic fermentation. They then have to rely on either anaerobic fermentation which produces alcohol or they must wait on oxygen to percolate down from the surface. That is the process you are overlooking and/or minimizing when you state that tomato fermentation is an aerobic process.
The next time you ferment tomato seed, check for the presence of alcohol on the second, third, and fourth days. If you find alcohol, you've got anaerobic fermentation. Don't just think about it, try it!
While you are at it, get a simple acidity test kit. You can sometimes find them in the aquarium section of large stores. Measure the acidity of the tomato pulp and then measure it again after 5 days of fermentation. If the acidity increased, guess what, you've got anaerobic fermentation.
Just because a container is open to the air does not mean that the fermentation process in that container is aerobic. Anaerobic fermentation can take place any time there is a restriction of oxygen availability such as is caused by the yeast using up the free oxygen in the bottom of the container after which they have to convert to anaerobic fermentation. Think about this a minute. Where does the bulk of the yeast growth and reproduction happen? Its at the surface where all the oxygen is available. Why isn't there major yeast multiplication down in the bottom of the container? You don't see any fungal mats down there do you?
Thanks Fusion for your succinct, systematic analyses. It seems pretty clear to me that both aerobic and anaerobic processes are involved, and that these will vary depending on several factors, which include:
1. the surface area of the substance being fermented,
2. the depth of the substance being fermented,
3. how often as well as how recently the contents were stirred, and
4. the amount of time that has elapsed since the process began.
Missed a couple more Martin.
Many beers are brewed in an open fermenter. Ergo, all beer brewing (including lagers) is not done in closed containers. What forms the oxygen barrier in an open beer fermenter? I wonder if carbon dioxide builds up above a container of fermenting tomato seed?
Re your point #2, yeast does NOT require oxygen to grow. It does require sugar in a liquid medium. It can grow using the anaerobic metabolic pathway. Oxygen is however required for the yeast to reproduce. You can't equate growing with reproducing. The energy cycle is fairly simple with the maximum extractable energy from aerobic fermentation but there is still an energy gain when the yeast uses anaerobic fermentation.
You still haven't told me if your fermenting tomato seed ever reek of alcohol. I know that mine do.
So the basic question is now answered. You smelled alcohol in your fermenting tomatoes and since the only metabolic pathway for yeast to produce alcohol is by anaerobic fermentation, we now have proof that your tomatoes are undergoing both aerobic and anaerobic fermentation with aerobic at the surface and anaerobic beneath that.
Aerobic - C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + lots of energy
anaerobic - C6H12O6 -> 2 C2H5OH + 2 CO2 + (LESS) ENERGY
Yeast cells will use oxygen if it is present, and break down sugars all the way to CO2 and H2O. In the absence of oxygen, yeast will switch to an alternative pathway that does not require oxygen. The end products of this pathway are CO2 and ethanol. The first pathway yields a lot more energy per sugar molecule consumed, and so it is the "preferred" pathway if oxygen is present.
The odd part about this is that I really do understand the chemical formulae and the reactions above since I went through chemistry with my daughter just 2 years ago. I'd never taken chemistry before that.
I'm glad to finally hear the words anaerobic respiration being mentioned.
The major pathways are:
aerobic respiration, where the final electron acceptor is organic
anaerobic respiration, where the final electron acceptor is non-organic ( this is not a common pathway and only certain microbes can perform it)
Fermentation, where the final electron acceptor is organic and products can be alcohol and/or mixed acids and other organic compounds, depending on **which** microbes are doing the fermentation.
There is no such thing as aerobic fermentation, which is really an oxymoron. Yes, one sees the term being used, but those using it appear to not be familiar with microbial physiology and biochemical pathways.
Since fermentation leads to a more acidic condition one has to assume that either the alcohol produced by yeasts is converted by bacteria and/or filamentous fungi to mixed acids or that other microbes such as filamentous fungi and bacteria are part of the fermentation from the beginning and are perfoming mixed acid fermentations, which lead to a variety of organic compounds including many different kinds of acids.
Almost all these discussions have assumed that yeasts are the major initial players and I don't *yet* know that to be true. One cannot compare a beer or wine fermentation with an open vessel fermentation where any microbes present in the air or on the tomato fruit exterior can be present.
I hope to have additional information on this aspect sometime soon and will start a new thread at that time to share what I've learned from others who know more than I do about the microbiological composition present in an open vessel non-controlled tomato fermentation. As I mentioned in the other thread I also expect the microbial composition to vary somewhat from vessel to vessel since microbial contamination would be expected to be somewhat random.
I looked at your link from a page on making Mead.
I repeat what I said above, and that's that those not familiar with microbial physiology and biochemistry would not possibly know the difference between aeobic and anearobic respiration and fermentation.
I also said that the phrase aerobic fermetation is in use, but improperly so.
Martin, I can post for you here a link to the three main types of metabolism that are known and operative. The explanations are biochemical. If you wish for me to do so I will.
From a strictly technical viewpoint, the aerobic reaction is an oxidation reduction. Oxidation because the sugar is combined with oxygen, reduction because the sugar is reduced to carbon dioxide and water. From this perspective, it is not accurate to refer to the process as "fermentation". Still, given that there are lots of webpages that refer to "aerobic fermentation", there is an argument of common use that can be made.
We also know that alcohol is produced and that the only possible way for that to happen is if part of the process is anaerobic. We also know that the liquid is more acid after 5 days of fermenting than it was at the start. The only way for it to increase acidity is through anaerobic fermentation.
Please note that I am neither attacking you nor defending Carolyn. My only purpose is to try to get to the truth of this question. I don't care whether the process is aerobic or anaerobic or some combination of the two. I have no axe to grind nor cud to chew. I do care that the process works and that it is fairly easy to do.
Yeast does not "break down H2O" Breaking H2O into its components requires a huge energy input. It normally occurs only in chlorophyll containing plants that use the suns energy as a pump to cause that separation. You can do a search for photosynthesis and chlorophyll if you want to see the mechanisms that make this possible. Since yeast does not normally contain chlorophyll, and since yeast is extracting energy, it does not separate water into its components.
Re flipflopping, I make it a point to change my opinion promptly and completely when evidence is presented to indicate that I am on the wrong path. I have not flipflopped at all since doing some real research about the process of fermenting tomato seed. Clear evidence including a few references has been presented that many statements you have made are incorrect. Have you changed your position as a result? If not, why?
The oxygen barrier in an open fermenter used in producing beer is a layer of carbon dioxide that accumulates above the fermenting vat. A lid is placed over the open fermenter which tends to trap the CO2 that is produced by the yeast. So long as that CO2 layer is minimally disturbed, a very effective oxygen barrier is produced which causes the beer fermentation to be anaerobic.
All of the information I have at this point indicates that tomato seed fermenting is composed of an early aerobic process followed by an anaerobic stage. Most important to me is that BOTH stages are required to achieve the desired end result. It doesn't stop there though. There appears to be a bacterial stage after the yeast has run out of sugars to digest. The bacterial stage is the point at which the acidity increases and is the point at which pathogens are probably eliminated from the seed.
Acid is added to wine mixtures because wine is NEVER allowed to go through a bacterial stage. If it did you would have vinegar instead of wine. Do a search for vinegar and see how it is made starting from just about any ethanol containing liquid such as cider or wine.
You infer that a fermentation process that has access to oxygen is of necessity an aerobic process. Do a search and you will find numerous links that clearly state the alcohol is produced ONLY from an anaerobic process. If alcohol is present and was produced by yeast, then the process was anaerobic.
Wow, when I bring home an heirloom tomato that I like the taste of I just put the seeds, gel and all, into some soil, water and put in a warm window....they always sprout quite well. But I have a greenhouse, so I don't have to save seed over the winter, I just grow plants all year.
I had some tomato seeds still germinate almost 100% this year and the tomatoes were grown out in 1990. so the seeds were saved in fall of 1990. now it is 2006 a good 16 years later and they were fine. I had them in a little plastic pill bottle with a loose fitting cap. they were left in the basement which is very damp but moderately cool.
I had 2 different varieties and both were fine like new seeds.
lots of stuff like lettuce was zero germination.
my tomato seeds were fermented washed with water and dried out on newspaper.
How ripe should the tomato be when the seeds are harvested? Like falling off the vine and too mushy to eat, maybe? I hope this doesn't offend anyone;-)
Nice to see this thread brought back to the present. It's a good example of what ignorance of a subject plus persuasion by debating team losers can accomplish. This was originally quite a technical thread which went into great detail about all aspects of fermentation. Eventually, a noted university professor was called in to have the final word on another thread. That person agreed with just about everything that you do not see in this thread. What did remain was also subject to dispute. By then, it was too late and all of the confirmed research contributed was lost forever. Don't fault the present Garden Web management as they had no part in creating an apparent mish-mash of disconnected replies.
I have saved tomato seeds successfully by simply spreading them (goo and all) on a paper towel and letting it air dry for a few days. Then I fold up the paper towel, put in an envelope with the variety name written on it, and stick it in the back of the fridge.
In February I unfolded the paper towel, spread it out on a dinner plate, covered with water, and let the seeds soak loose. -- Then picked them up with a knife and put them in a seed starter mix to germinate. They all germinated, and produced quite well. --
Sure wish I had learned to do this while we still had the St. Louis Blues Tomato plants that I am now looking for seeds from!!!
Oh my gosh! I was reading another thread. The guy was talking about his various tomatoes and where he got them. One variety started from seeds he got from tomatoes from the farmer's market! What a great way to get seeds that will grow locally and you get to taste them too to decide if you feel they are worth buying
Katy in CA.