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Using a pH meter and lowest pH to kill botulism

Posted by cabrita 9b (21) (rosetalleo@gmail.com) on
Tue, Jul 21, 09 at 11:05

I have a basic canning/pickling question. Many questions really, but just one today.

I understand that the way pickling works is by reducing food pH so botulism and other nasties cannot live in the food. A quick google search gives me pH 4.8 as the lowest that can host botulism. Does this mean that as long as I achieve pH 4.7 or lower, I am save just using BWB canning? or even just refrigeration?

I recently got a pretty accurate pH meter (SPER scientific large display pH pen). I have been using it for garden soil samples, but it can be cleaned well. I am also going to make/buy a buffer solution to increase the accuracy. I was wondering about measuring the pH of the food prior to canning, both for information/curiosity, and for safety reasons. Do any of you measure pH for canning/pickling purposes?

It turns out I do not like really sour pickles, or really acidic tomato sauces, so I would prefer to stay near the 4.7pH range, allowing 0.2 pH for meter accuracy. I also wanted to confirm that 4.7pH is safe enough. Thanks for your comments and answers.

OK, I said just one question but there is a related one. Since both salt and vinegar are used in pickling, and both have a preservation effect. Is there a way to measure the synergistic effect of both salt and vinegar? like if i use enough salt, I can raise the safe pH some?


Follow-Up Postings:

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RE: Using a pH meter and lowest pH to kill botulism

Does this mean that as long as I achieve pH 4.7 or lower, I am save just using BWB canning? or even just refrigeration?

No because first the minimum required pH is 4.2 or lower (which is why citric acid must be added to tomatoes that are normally 4.6-4.7) and second because the pH doesn't hold stable over storage time. As water and air leach out of the canned foods into the brine, the pH gradually rises back into the unsafe zone that allows for any botulism that was not killed during processing to thrive once again. So we process correctly to begin with to kill the botulism and then the change in pH is of no concern.

The use of a pH meter and even litmus paper was approved once upon a time but that approval was undermined by ongoing research and canceled several years ago. The FDA still allows meter (top of the line commercial ones) use in commercially canned high acid products but their use isn't approved for home food preservation.

Is there a way to measure the synergistic effect of both salt and vinegar? like if i use enough salt, I can raise the safe pH some?

Don't know but since there are recipes that do not use both - fermented pickles, kraut, etc. use only salt and water - I would assume the answer is no. At least not to any degree that would insure safety. But Linda Lou may have some info on that issue or you can always contact Dr. Elizabeth Andress at NCHFP.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

pH MUST also be the same throughout the canned product. For dense things or watery things, the pH would require a lower level, meaning more added acid to evenly penetrate the dense products. Salt and water as a brine induces enzymes within the cukes or other products to ferment in such a way that they produce lactic acid. This lactic acid is meant as an option to vinegar, and must be high enough to also make things safe to can. I pickle a small thin pepperoncini and use only white vinegar and salt, with no added water. All home brands of white vinegar are at 5% acidity now, whereas some years back they could be as high as 20%. Commercial picklers use the 20% and dilute it accordingly. Its far less expensive to transport a higher strength vinegar, and add the necessary water when actually pickling/canning commercially.


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ksrogers...actually you have to check the bottle on the acidity in vinegar. Being new to canning and pickling, I had no idea that vinegar was different from one bottle to the next, but after reading on here, I discovered it is. One bottle I had was 4% and another bottle was 5%. So check the label!!


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RE: Using a pH meter and lowest pH to kill botulism

The most common white distilled vinegar is Heinz brand and is always 5%. Special vinegars, like wine, balsamic, and rice are lower in acidity. I have not seen any higher than 5%. Cider vinegar is milder tasting but is also at 5%. I am well aware of the lower acidity ones and never use them for any homd canning of an kind. With Heinz brand, there is no need to check unless it was from a vinage bottle made about 20 years ago, where it was the actual 20% strength. The label even stated to dilute it prior to use. I spent many months searching for a supplier of 20% and found a weed killer type from Marshall Grain in Texas. Unfortunately its not 'food grade' anymore.


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I wonder what is the pH difference between 4% and 5% vinegar.

I just measured the pH of the last pickling solution we made. It had gone trough the BWB process and been pickling the green beans and spices for over two weeks, so one would think it has equilibrated. The pH read 3.8 for an initial solution 1/2 water and 1/2 vinegar (white, 5%). I would not care for all vinegar, too sour for me.


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RE: Using a pH meter and lowest pH to kill botulism

Salt s not a preservative unless in HIGH concentrations, as in jerky making. It is not for preservation in pickles or other foods, only for flavor. In most things it is optional. Not unless you are fermenting, to get proper fermentation. Please, do not try to do this yourself ! We never recommend anyone try to test their own foods. The ph can and does change as they sit in the jars !!! Plus, you have no way to measure density. Density is also just as important as the ph level. You are playing dangerously, in my opinion.
I teach food preservation safety and I would not even try to test my own foods.
I suggest you take the free online course on safe food preservation by the Univ. of Georgia. That and get yourself a new copy of the Ball Blue book and use it or follow the recipes at the Univ. of Georgia.

Here is a link that might be useful: Free online course.


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Ksrogers...I bought a "cheap" store brand of vinegar to use for DH to soak his disgusting yellow toes in...another use for vinegar---to kill "digger" the toe fungus! LOL! It was 4%. I never knew there was a difference, but evidently it was. Thanks to all of you, I found that out. Not sure if that one percent makes that much of a difference, but I decided not to use that bottle when I was doing squash pickles.


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Yes, it makes a big difference. Only 5 % acidity or higher is safe to use for any preservation of foods.
The best thing I have found for fungal infections is tea tree oil. That is what the diabetes ed. classes taught me.
Just a sidenote that may help you out.


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RE: Using a pH meter and lowest pH to kill botulism

linda_lou, I am trained as a scientist and have worked in labs most of my life. pH testing is not that hard. I know there are faulty testing, pH papers and color matching is not good enough. A basic knowledge of chem is good, but anyone could do it following the instructions that came with my meter and goggling a few terms.. In any case, the information cannot hurt. After I saw pH 4.2 mentioned by Dave (I understand this is the pH of the initial pickling solution, to allow the total content to still be below 4.7 after the pickle/brine solution has penetrated a lower pH vegetable) and Ken saying he uses all vinegar at 5% I wanted to check that i was not endangering folks taking the last pickle batch out of our hands. I used 1/2 water and 1/2 5% acid, so it is good to see that I used sufficient vinegar on low acid veggies (green beans). Measuring density is not that hard either, just weight the produce and see how much water it displaces on a beaker.

The question was posed wrong by the way, I meant to say, what is the highest (not lowest) pH that I can have, and still inhibit botulism bacteria?


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RE: Using a pH meter and lowest pH to kill botulism

I meant to say 5% white vinegar and water, 1/2 and 1/2....sorry about the typo. I posted the recipe in the legume forum, I will post it here later.


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RE: Using a pH meter and highest pH to kill botulism

I meant to say 5% white vinegar and water, 1/2 and 1/2....sorry about the typo. I posted the recipe in the legume forum, I will post it here later.


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RE: Using a pH meter and lowest pH to kill botulism

The vinegar ratio doesn't hold true for all vegetables since they contain different amounts of water to dilute the solution once canned.Plus the ph of each veggie will vary. Some require full vinegar, as in pickled cauliflower. It also depends upon which other things are added, such as fresh peppers, onions, garlic. That changes the ph of the whole product.
The density in sauces and things would be hard to determine at home. We don't have any amounts that we can go by at home for deciding just what that safe density would be. I can see perhaps in produce, but not in a sauce that someone would make.
The tested recipes we have are just that, they are already tested for the proper acidity for home canning. The food scientists have already done that for us. Those ARE the safe conditions. We teach people to change the recipes by using different dried herbs and spices to make them different. As I said, the salt won't matter in most things.


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RE: Using a pH meter and lowest pH to kill botulism

This abstract suggests that pH 4.2 does not kill botulism.

Appl Environ Microbiol. 1977 July; 34(1): 30-33

Effect of storage time and temperature on the survival of Clostridium botulinum spores in acid media.
T E Odlaug and I J Pflug
ABSTRACT

Clostridium-botulinum type A and type B spores were stored in tomato juice (pH 4.2) and citric acid-phosphate buffer (pH 4.2) at 4, 22, and 32 degrees C for 180 days. The spore count was determined at different intervals over the 180-day storage period. There was no significant decrease in the number of type A spores in either the tomato juice or citric acid-phosphate buffer stored for 180 days at 4, 22, and 32 degrees C. The number of type B spores did not decrease when storage was at 4 degrees C, but there was an approximately 30% decrease in the number of spores after 180 days of storage at 22 and 32 degrees C.


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Spores. Not the toxin. Spores are everywhere, all around you, the air you breathe. Spores are like seeds. They don't change into the bacteria that create the deadly toxin unless the conditions are right.


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RE: Using a pH meter and lowest pH to kill botulism

  • Posted by olpea zone 6 KS (My Page) on
    Tue, Aug 11, 09 at 15:26

Sorry for resurrecting this old post, but I ran across a canning question on this forum, which caused me to do a little digging, and now I have another question related to this thread, I wonder if someone could answer?

Here's the background. About 15 years ago, we started making salsa from a recipe (handwritten) that I have no idea where it came from. I love the recipe, but the original recipe didn't include adding any acidifier to the salsa. Not knowing any better(this was before the internet) the first year we canned it, there was lots of spoilage, which we had to throw out. When we made it after that, we always refrigerated it. A few years ago, I learned that low acid foods need to be either pressure canned or acidified. I had assumed since salsa was largely tomatoes, the amount of acidifier needed for salsa would be the same as for canned tomatoes. Today I read that since salsa has more low acid foods, it needs more acidifier. Unforturately, I've made several gallons of salsa this summer using the amount of acid recommended for canned tomatoes. Now I'm questioning whether it's safe. I know I could simply refrigerate it, but I don't have that much refrigeration space.

After reading this thread, I went down and opened a quart to test the pH. I've read the warnings on this thread about testing your own food, but I have a good pH tester that is calibrated with an accurate buffer solution. The salsa tests 3.8 pH. Learning from this thread that pH can rise over time, my question is, how much will it rise? I could test each bottle as I open it, but it's a hassle to recalibrate the pH meter each time. Is 3.8 pH a low enough starting point?

Thanks


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I think the magic number is 4.0. Yours are OK. To acidfy, try adding bottled LIME juice and cider vinegar. These two add a lot more character to a salsa. You can also use citric too, but because salsa has many facets in taste, its nice to add a few more. I made some roasted chicken using lime juice and my mom had nevr had such a combination. At that time, it was her favorite way to enjoy grilled chicken outdoors.


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IF it is really 3.8 and IF it remains at 3.8 then yes, it would be safe. But those are 2 big IF's. And therein lies the problem. ;) Even commercial pH equipment is constantly re-calibrated and cross-tested so are you comfortable with the readings from your meter? I wouldn't be given the risk.

And as to stability of pH, that all depends on storage conditions and age. Cool and dry and less then a year - probably. High humidity, brief exposure to heat or inconsistent temps or longer than year - probably not.

Alternative to dumping - open the jar, boil the contents for 15 mins., re-jar into new jar and into the fridge. I wouldn't but it is up to you.

Bottom line - no, it can't be guaranteed safe so it is your choice.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

No,it is not safe. It is not safe to assume it will be. Testing your own foods is like playing Russian roulette with a loaded gun.
I teach food preservation safety. I would never say this is safe.
Only tested recipes and methods from a reliable source should be trusted. Ones from the Ball Blue book or any of the Univ. extension sites, especially the Univ. of Georgia are tested and safe. Some other books and info online may or may not be. Trust your safety to those who are trained in the field of food preservation.
It is too late to reprocess the salsa or trust it. Sorry, that is the safe information. Even if you boil it, you can contaminate the can opener, the counter, a spoon, etc. Get it in a cut, or splash in your eye. You get the idea.
I would chalk it up to a learning experience and not do this again.


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RE: Using a pH meter and lowest pH to kill botulism

These posts are interesting, informative, and troubling at the same time. I'm a chemistry professor at a university. It seems strange to hear that "testing your own foods is like playing Russian roulette...only tested recipes and methods from reliable sources should be trusted." Doesn't this raise anyone else's eyebrows? It is becoming more difficult to get high-acid tomatoes, for example, so if we follow a "reliable" recipe but use a hybrid tomato by mistake, we may be inadvertently risking our health. If we "trust" that the vinegar is at least 5% as stated on the label, and it is really 4.3%, we are also at risk. If the water quality your area is slightly alkaline, your water may be neutralizing some of the acid you add, which would then reduce your acid content without even knowing it.

There are too many variables in your "canning" experiment to simply resign yourself to a "trusted" recipe. Although those are important, I would still suggest a pH meter to add another level of quality control. It is simply naive to "trust" a proven recipe but not use the technology we have available. I've attached a link to a reasonably inexpensive pH probe. Keep in mind, food-quality researchers who test acidity use pH probes and frequently calibrate them. This is no different than checking your bathroom scale to see if it is zeroed before you get on. That doesn't mean the scale is faulty, it just means you set the scale before using it...

I hope some of this helps.

Here is a link that might be useful: Large Display Waterproof Ph Meter - Pen Style By Sper Scientific


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The alkaline water is one variable that troubles me. Our water is not only hard, it has a high pH. I've wondered about this for awhile.
Seems as if, someone like Chmst1999 or cabrita would be fully qualified to take an already tested recipe and be even safer by verifying pH with a calibrated, good quality meter.
I'm not saying they should or need too but it doesn't seem like it would hurt. The difference between 3.8 and 4.2 is enormous so would provide a pretty high safety margin.
I can also see why, no trained food preservation specialist can recommend this technique, maddening though it is for a highly trained scientist.
My background BTW, is medical school, Masters in Nutrition and undergrad to include animal science classes up to high level graduate classes. These included food science in a commercial light.
But, I will still follow only approved recipes, can't quite wrap my head around why pureed sauce can be less safe than chunky, as I read in a recent post.
Sometimes you have to look at the population that our canning recipes are geared for. They are written for someone with a 6th grade education and have a pretty high margin of safety to account for stupidity.
Seeing the average level of intelligence of people coming through the ER it's a wonder some people can figure out how to boil water!


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RE: Using a pH meter and lowest pH to kill botulism

Hopefully, this discussion has given everyone more things to think about. It has for me.

The more I think about it, the more I believe the water quality is the essential variable to test. Alkalinity causes all sorts of problems. For example, my in-laws all have varying degrees of acid reflux, but it only seems to become a problem when they travel. When they go on a trip and drink "city" water, they always experience acid reflux problems. They always blamed the "city" water and said that the "city" water was giving them heartburn, but that didn't make sense to me. However, when we tested their well water, we found that it was alkaline and had a reasonably high pH (greater than 8.5). Since pure water should have a pH of 7, their well water was acting as an antacid and their bodies were conditioned to produce more acid all of the time.

Think about what would happen if they canned with their well water using any recipe. There is no way they would be getting their pH as low as necessary without adding significantly more acid.

Of course, I'm not saying that most people should just make up a canning recipe without sufficient knowledge. I think the recipes account for a lot of variance in conditions. However, a pH meter is a good way to be sure the acidity is sufficient. We tell people to change the cooking time, pressure above the liquid, etc. depending upon elevation, so it doesn't seem like a stretch to tell people to get a pH meter and check the acidity.


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Are canning recipes tested with various water pHs to account for these differences?
I would hope so!


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RE: Using a pH meter and lowest pH to kill botulism

I am very disturbed whenever anyone says that testing your own recipes are dangerous. Anyone with a basic chemistry understanding should be able to test a recipe to insure that it is 4.2 before water bath canning.

I have tested my tomatoes prior to canning and they change every year. Once you start making salsa by adding onions, garlic and peppers, you would have no idea whether it was safe to can without using a pH meter.

By using an pH meter you can take control of your recipes and make them NOT dangerous. Anything below 4.2 that you cannot add Bottled Lemon juice to (I like Volcano!) or citric acid and lower the pH should be pressure canned or refrigerated or frozen.

The USDA says this you shouldn't make up your own recipes. They are also the ones who say it is safe for my neighbor to plant GMO corn.

We don't have to be sheep. Educate yourself. Test your your recipes, be safe, but don't feel like you need to follow every government recommendation. For God sake, Ball is still making lids with BPA in them! I have switched to European lids and I believe they are superior.

I have been canning for 20 years. I do not can like I did 20 years ago. There is no guessing in my kitchen.

If you buy a meter:
Accuracy: This should be the first consideration. Accuracy is listed as a range of 0.X pH units. This means the meter may read so many pH units above or below the actual pH of the product. Since you will be using or loosing batches depending on the pH reading, a narrow accuracy range is important. Considerations include:

- For food processors of products with pH between 4.0 and 4.6, a pH meter with an accuracy of 0.01 - 0.02 pH units is sufficient and required.

Calibration: All pH meters must be calibrated (checked against a known standard) to assure accuracy. Most meters can be calibrated to at least two standards at the same time.
- Calibration Standards or Buffers: You should order at least 2 buffers, pH 7 and pH 4, for your two-point calibration. The pH 4 is necessary because your meter should be calibrated to a standard that is no more than 3.0 pH units from your product. Sometimes buffers are sold in sets of 4, 7 and 10. You don't need the 10 to do canning. Remember you are shooting for 4.2.

Calibration takes time. Canning takes time. If you are going to do it. Do it right. Don't be afraid to re-check a jar after being in storage for 6 months.


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So, are you saying YOU are going to carry liablity insurance to cover what you are saying ?? I will not endorse anything not tested in a lab and I will not do so without liablity insurance.
Do what you want, but know that legal liablity is also something that should be thought about.
What risks you take in your own kitchen are up to you, no one will stop you, but we sure like to provide what we know is safety tested, as well.


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Since we are soap boxes I'll just add that my goal is different from yours. Mine is to get people to the point where they follow the current guidelines to start with because then they would be "mostly safe" at least. If they then want to move beyond that to testing their own products for additional safety, fine. That is their choice.

But since the vast majority of home canners aren't even aware that any guidelines exist much less follow them, or have any grasp of the concepts of pH much less density I will continue to focus on that instead.

If one believes even 1/2 of what gets posted on food preservation forums then learning how to use a pH meter is the least of their problems. You'd be amazed at what folks who claim to be experienced home canners will do much less what the ones who admit to being inexperienced will do. Making up their own low acid recipes and sticking it in a jar and make up a processing time is common practice. And "I have been doing it that way for years and I'm still alive" is their justification.

Just a few comments I have run into in the past 3 days on 2 other forums:

Fats and thickeners? No problem. Sure you can can butter and milk because Jackie says you can. You can mix the types of meats as long as you process for the longest one's time. BWB hot dogs? No problem. BWB green beans and corn? No problem if you add aspirin. Add acid to anything? Why? Good heavens, no! Use a pressure canner? Not on your life! I've been canning for 30 years but never heard of the BBB. What is it? My gauge (which was 30 years old and never tested) says 10 lbs so everything is safe. If the instructions say BWB for 30 mins. then pressure canning for 10 is plenty. I pressure canned them for 2 hours but the weight never jiggled so are they safe? When you can your lasagna do you use cottage cheese or ricotta?

Sorry but with that level of food preservation ignorance out there can you imagine what it would be like if you turned some of these folks lose with a pH meter?

Dave


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RE: Using a pH meter and lowest pH to kill botulism

Professional people are expected to have a certain level of competence in their particular discipline or field of expertise. Its also expected that they will professionally and accurately perform their services, according to the common standards of conduct of their profession. For whatever reason, intended or unintended, if a professional person fails on the job, they can be held responsible for any harm they cause to another person or business. This is when you need liability insurance.

I do not provide advice for a fee. Therefore, I do not need to carry liability insurance for stating an opinion. So far, no one from the garden web has sent me any money for advising them to think for themselves.

I appreciate your concern, but I stand by what I said, not testing, even when using an "approved recipe" is more dangerous.

For those of you interested in pH meters, Google: Cornell University Purchasing pH meters.

Many local colleges have classes on food safety and canning.

Worried that something you canned isn't safe?

Beverly Ellen Schoonmaker Alfeld (known as Jamlady) will test a jar for you.

I'm in the kitchen making zuke bread & butter pickles, from one of her recipes. Am I going to test it? Darn tootin.


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I have to believe that safety tested recipes carry a huge margin of safety to make up for the fact that the lowest common denominator is a 5th grade educated person witH an IQ of 70 and no training in food preservation.
How else could volume measured recipes, which have a huge chance for measurement error be deemed safe? If it was that critical to accurately measure ingredients perfectly, they would only give weight measured recipes.
The amount of error that occurs in measuring a dry flour or water by volume is enormous by baking standards. I can only imagine the Amount of error in measuring multiple cups of a chopped tomato or pepper!


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RE: Using a pH meter and lowest pH to kill botulism

Dave, I agree that there is a great deal of ignorance out there. I figured I'd lost most of them when I started spouting pH buffers.

But then again, there are a great many educated folk out there who are not afraid to learn new things. I believe it's time we took hokus pokus out of canning and put the science in.

My goal is to have people take control of their lives with self-acquired knowledge and increased self-sufficiency, starting in the garden and moving into the kitchen.

We should know what we eat. We should not be so ignorant of basic science that we think an aspirin in the jar or the open kettle method is safe.

I'm sorry, I think I'll go back outside and weed corn and keep my canning to myself.


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If you think liability insurance is only for paid people, then why do our volunteers have to have insurance ?
I spend a lot of my time as a volunteer. I only get paid for certain jobs I do. I have to have liability insurance for both situations.

I liked how Carol described how acidification takes place in her example on the other thread. Great job, Carol !
She is correct in what she said.


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RE: Using a pH meter and lowest pH to kill botulism

I believe it's time we took hokus pokus out of canning and put the science in.

I agree completely which is why I am pleased to have all of the scientific input available from NCHFP/USDA because without it we would ALL just be guessing and the rate of home canned food illness would be much higher than it is.

The history of home food canning publications at NCHFP are an enlightening read. ;)

Dave


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RE: Using a pH meter and lowest pH to kill botulism

I found a great historical read in the free section for IPAD books. It's a post WW1 book on canning. Very fascinating and kind of funny!


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RE: Using a pH meter and lowest pH to kill botulism

this thread is very interesting ! I too have been in medical research for 25 years and believe the usda guidelines must be supersafe to account for the lowest common denominators in I.Q. and also water pH variations. but i think i am buying a really good pH meter and a pressure canner for tomato products- because the government would like to do all our thinking for us, and i just won't let them!
on the other hand, i'd like to know the history of deaths from home canned foods. were people dropping like flies in the 18th century? or before 1950 ? saying "i've canned this way for 30 years and i'm still here" may be an excuse-and it's also an observation.
this is a slippery slope, but what exactly is the chance of getting botulism poisoning from a splash in the eye, and is it dose dependant? considering the greater chances of dying from an auto accident or smoking, it sounds a bit like a scare tactic. wouldn't cargill and monsanto love to have everyone stop canning and buy their "safe" foods? you know, the ones with all those recalls?


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RE: Using a pH meter and lowest pH to kill botulism

but i think i am buying a really good pH meter and a pressure canner for tomato products- because the government would like to do all our thinking for us, and i just won't let them!

Your choice of course but if "tomato products" is the only thing you are canning then the risk and $$$ hardly seems worth it. Guidelines are easy for them. No pH meter needed.

on the other hand, i'd like to know the history of deaths from home canned foods. were people dropping like flies in the 18th century? or before 1950 ? saying "i've canned this way for 30 years and i'm still here" may be an excuse-and it's also an observation.

I think it is pretty clear from all the information above and in the other discussions here of this issue that not only was vinegar much stronger than it is today and that after-opening hard boiling of the foods was done to kill the toxin but that statistics weren't kept that far back. ;)

Still, since you are in medical research, then you likely have access to even more online publications and current research on the issues associated with botulism than most of us do. For most, the USDA and CDC stats are sufficient but that is a good place for you to start your research that will help you make an informed decision. Canning is a science after all.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

Odd to come across this discussion today. I was just wondering out loud to my husband this morning if I could get a pH meter and test food as I canned it. I did not know that pH changes over time as the food is stored.

On thing that bothers me, though, is the insistence that the USDA and Ball are the only correct sources of canning information. I have a hard time believing that nowhere else in the world can be trusted with canning instructions. It seems a bit like American arrogance to have that attitude.


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RE: Using a pH meter and lowest pH to kill botulism

As far as I know, no other places do the testing as was done here, it takes between $10,000 and $50,000 per recipe to test them.
Now, someplace like the Williams Sononma cookbooks as and example, are not going to test those recipes in books for that kind of money.
It isn't American arrogance, that I can see, it is a matter of time and money spent on testing.


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RE: Using a pH meter and lowest pH to kill botulism

It is the "lowest common denominator" thing and the fact that people don't want to be responsible for their own lack of good judgment.

Why does a plastic bag need a warning that it could cause suffocation?

Why does my bottle of water have a warning that the cap is small enough a child could choke on it?

Was does the sun shield that goes in the windshield of my car say "REMOVE BEFORE DRIVING CAR"


But what I really wanted to say - I followed the link Lindalou posted way back (july 09) at the start of this thread (before I realized how old it was) and got myself signed up for the online class.

I thought they had stopped offering that class because of lack of funding, so I was sure glad to see it available.

Cathy


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RE: Using a pH meter and lowest pH to kill botulism

On thing that bothers me, though, is the insistence that theUSDA and Ball are the only correct sources of canning information

Not really, ;) there is also Bernardin in Canada (homecanning.com), freshpreserving.com, several land grant university extension websites, and several other canning books we have discussed here in the past. Mrs. Wages.com also posts tested recipes using their products.

While it is true that much of their recipes are based on the USDA testing that comes out of the University of Georgia, as Linda Lou said, why would they want to spend the time and the money duplicating all the research just for some 'national' label? Unless of course they found the research to be invalid. Apparently they haven't. ;)

Dave


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RE: Using a pH meter and lowest pH to kill botulism

Research is being done all the time concerning testing for pathogens in processed food and I read about a month ago of a new lower-cost, fast response botulism test being developed. It would benefit the food industry and distribution channels primarily, but I can see with the rapid and cheap DNA tests and anti-body tests where food safety tests could be within reach of many sources in the not-to-distant future.

Here is a link that might be useful: Quick Botulism assay


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RE: Using a pH meter and lowest pH to kill botulism

I just thought this thread interesting. With economic problems around the world looking very sticky I'm betting more and more people start to can.

Looks like I'm buying a pressure canner and some litmus paper. I like to play so litmus paper seems to be the cheapest way to test my recipe.

What I've read here has made me more comfortable with what I'm canning. Btw... I studied some philosophy and advise never to be 100% certain of anything. Smart people make dumb mistakes every day... we are human.


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RE: Using a pH meter and lowest pH to kill botulism

> Looks like I'm buying a pressure canner and some litmus paper. I like to play so litmus paper seems to be the cheapest way to test my recipe.

And the least reliable. (litmus paper) Am all for the pressure canner though.


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RE: Using a pH meter and lowest pH to kill botulism

I studied some philosophy and advise never to be 100% certain of anything. Smart people make dumb mistakes every day... we are human.

Very true. But while cooking is an art and as such, other arts such as philosophy can play a role, canning is a science. There is ample instruction and evidence available to anyone interested that mistakes are easily prevented - especially hazardous ones.

Using litmus paper to test your recipes is one of those potentially hazardous mistakes. So is "playing" with canning recipes. Please don't make your gifted friends pay the price for your need to "play" at canning.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

Good advice, John and Dave !!! I so agree.


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RE: Using a pH meter and lowest pH to kill botulism

Before you go with the litimus paper test, you need to research shelf stability of acids. Just because it tests OK before you put it into the jar, does not mean it's going to stay that way with your own made up recipies.

What you also need to do is periodically take some out and re-test, and for safety sake, retest when you open to make sure the PH level stayed low enough. With PC, you kill the mircoroganizm, with low PH, you simply keep it from getting active, and if for some reason the PH level rises, it will get active and produce spores.

I have found it's simple enough to can up basic sauces, and then customize them after opening. There are lot of very good tested recipies out there for most condements and there are enough safe ways to modify (like changing dry seasonings) to have a variety.


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RE: Using a pH meter and lowest pH to kill botulism

I've read this thread before, and now again and the new posts.

I have to admit I'm confused. While some folks have seemed to advocate for Ph testing recipes they make up, there are some who say they want to test the Ph of their foods to make extra sure they are safe... just in case the water or the fruit or the whatever threw the Ph out of whack.

And other people are saying that only tested recipes are certain of safety -- and you shouldn't test because it's not accurate.

But then, I'm thinking that if I used tested recipes, and got in the habit of testing them with a calibrated instrument, both before canning and after, that I would build up a little database of what the Ph of my food was. Then, if my tested recipe DID have something happen to it, I would be more likely to know if it really WEREN'T safe, right?

I guess I don't understand not having more information rather than less....


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RE: Using a pH meter and lowest pH to kill botulism

Okay, have been doing more background reading and starting to understand the issue around the consistency of the pH measurement. The information you're getting may so off (to a larger degree than I would have thought), and thus my premise of "more information" may be inaccurate if that's true. And perhaps you'd then be misinformed about the pH of your food...


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RE: Using a pH meter and lowest pH to kill botulism

Not only mislead by your pH starting readings but there is also the pH stability issue Macy mentioned. The approved recipes have been repeatedly tested over time for pH stability and bacterial growth - 2 mos., 4-6 months, 9 mos. etc. That is one reason why multiple samples must be submitted when a recipe is submitted for testing.

So we would have to test and retest and then test again our own recipes upon opening the jar.

And their testing is done with highly calibrated instruments, not litmus paper which most of us learned in high school chemistry class can be easily affected by just the humidity in the air or the oil on your skin. That professional equipment is not normally available to the home canner without spending umpteen $$$$ and even then requires frequent recalibration to be accurate.

Possible? Maybe. Practical? No.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

Suppose you could vacuum-pack a meat (probably chicken or turkey) with a highly-acidic marinade. If it were stored at room temperature for 24 or 48 hours, what would be the likelihood of it being safe to eat?
If the meat was raw when packed?
If the meat was thoroughly cooked when packed?

Many thanks!

Edit: Sorry, I should have posted this on the main forum and can't figure out how to delete this post.

This post was edited by NearlyNomads on Sun, Jan 20, 13 at 16:42


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RE: Using a pH meter and lowest pH to kill botulism

I don't know the likelihood but I do know that meat is very dense, so odds are the center of the meat is not acidified at all.

Add to that the leaching of meat juices (high pH) into the acidic marinade, thus reducing the acidity of the solution.

A lot can change in 24-48 hours.

Carol


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RE: Using a pH meter and lowest pH to kill botulism

Because of the "new" regulations on added acid to
tomatoes, I only water bath pickle beets, pickles
and fruit products.

I got away from canning for about ten years and
boy what a differance that made. The tomatoes and
every thing they were added to had such an acidic
taste. In a word, they were awful tasting

Not having my own testing lab, the only safe water
bath method for me is I don't can tomato products


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RE: Using a pH meter and lowest pH to kill botulism

Use citric acid instead of the bottled lemon juice. It doesn't change the flavor in any way.

Dave

PS: the acidification "rules" aren't new. They went into effect in the 70's.


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RE: Using a pH meter and lowest pH to kill botulism

I used the citric acid but that gave
the tomatoes an acidic taste. Used in
soups and chillies, that acidic taste was
very noticeable. Therefore no tomato canning
for me.
I don't think lemon flavored tomatoes would
be any better.
I would not care to can contrary to the
guidelines, even though the guidelines cause
the tomatoes to taste bad.

PSS: Dave, that is why I put the -new- in "" .
john


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RE: Using a pH meter and lowest pH to kill botulism

Stumbled onto your forum and this thread while researching on pickling fish that do not need to be refrigerated. I have an older book that references useing 15% acetic acid vinegar instead of the modern 5% to pickle the fish (also states the fish would have to be soaked in water for a day or two before eating). Since fish reach equalibrium readily, especially in smaller bite sized pieces and 10% acetic acid vinegar is listed at a PH of 2.4 (5% listed as 3.6) would making up a batch of 10% or 15% acetic acid vinegar and useing that satisfy the lower PH need thus eliminating the need to refrigerate. Food grade 99.85% acetic acid is available at Amozon and since distilled vinegar is just acetic acid and water mixed making up a proper solution would be easy.


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RE: Using a pH meter and lowest pH to kill botulism

I don't know that any of us are in a position to draw conclusions regarding the relative safety of that recipe, but I find myself wondering about the texture of pickled fish held at room temp in an acid solution that strong.

Carol


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RE: Using a pH meter and lowest pH to kill botulism

Agree with Carol that the safety of that approach is impossible to determine except perhaps by a trained food scientist. Safety aside, not only the texture but the appearance and most importantly, the taste, of the end product would be questionable in my opinion.

Is your primary goal making pickled fish or having fish that can be stored without refrigeration? Are smoking and/or canning options acceptable? Current instructions are available for both.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

I think also that we often forget that "not refrigerated" does not necessarily mean room temp for some of these older recipes. A lot of people kept perishables in root cellars or stillrooms where the temperature even on hotter days would be considerably lower than ambient. People also were very cognizant of storage limits and a lot of foods would be consumed speedily, not kept for long periods.

For really long-term storage I'd guess fish would be salted, smoked and/or dried.

Carol


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RE: Using a pH meter and lowest pH to kill botulism

I don't have time to read the whole thread, so I apologize if someone else has mentioned this - but you may wish to read Putting Up by Stephen Palmer Dowdney. He sells canned foods in a boutique business and teaches the government recommended methods, which are quite different from home canning methods. They involve reading the pH of canned food.


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RE: Using a pH meter and lowest pH to kill botulism

you may wish to read Putting Up by Stephen Palmer Dowdney

We have reviewed this publication here before. Read it sure. Use it for guidelines for home food preservation? Please don't. Its interpretation and application of commercial FDA guidelines has little, if any, relevance to safe home canning. For example, the errors resulting from using litmus paper for pH testing, as he recommends, is well documented.

Dave


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RE: Using a pH meter and lowest pH to kill botulism

Smoking and pickling won't make the food safe for room temp. storage.
Smoking is only a flavor agent. It won't preserve anything.

I don't see why you don't just use our current recipe and method for pickling fish. It turns out fine.


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RE: Using a pH meter and lowest pH to kill botulism

Hot smoking still requires refrigeration after, cold smoking/jerky can be done, canning is a no brainer, most salting instructions say refrigerate after, have done and am doing refrigeration after required pickling. What I was after was a historicly authentic food safe way of preserving fish by pickling that did not require the refrigeration of the jars. The purpose of this is my own edification/increasing my knowledge base/historic cooking research/alternatives in storage. Do my current methods work and are safe? Yes. Looking to expand them, The question I ask is could, THEORECTICALLY, this process using the increased acetic acid vinegar meet the criteria to keep the PH of the entire batch below the 4.2 PH level. Yes I aknowledge there may be a change of texture and the flavor may take on a more vinegar taste, but I have norske ancestory (think lutefisk, but I dont want to go in that direction). What brought me to post was I did notice some scientific types posting toward the beginning of the thread and was hoping they might answer. I know I will not get a definative yes answer as there is no .gov approval stamp but I would like opinions.


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RE: Using a pH meter and lowest pH to kill botulism

Should have posted this sooner but here is a reply I got back from an inquiry -
Thank you for your interest in the National Center for Home Food Preservation. Regarding your question:

(My sent message) Background, I am a home food preservationist with an extensive history of home sausage making (both with hot ((refrigeration required)) and some cold smoking ((humidity and temperature controlled to produce country cured sausage, no refrigeration required)), home canning (pressure canning only, I do not trust water bath under any circumstances) and extensive dehydrating experience. I have done a little pickling under the recommendations that the USDA has out in regards to fish and hardboiled eggs (including the need for refrigeration). However in my research into historic preservation techniques I have found references to pickling (especially) fish preserved at room temperature. The references also stated that the vinegar solution used at the time was homemade and was of strength higher then the present 5% available for modern commercial sales. Given that botulism spores growth is inhibited at a PH of 4.6 and they can not therefore produce the toxins, the fact that! a 10% or 15% acetic acid can be readily produced using food safe glacial acetic acid (99.85% available commercially mixed in proper ratio with water (yes, acid to water, I remember basic chemistry) and the PH of the 10% solution is approximately 2.4 and given that 1.5” x 1.5” x 0.75” pieces of fish would readily equalize PH is this theoretically a safe preservation method. Please do not give me the standard rely of not recommended or approved due to lack of experimental data etc. brush off, I am just looking for a theoretical answer.

(The reply) This is Elizabeth Andress, Director of the National Center. I personally apologize for not getting back to you sooner, but we have been trying to keep up with people needing help with more standardized recommendations and methods of preserving.

I can tell you that under the circumstances you describe with the low pH environments, that theoretically botulism spore germination and toxin production does not seem likely. But that is indeed as much as I can say. You would want to make sure the fish pieces get below pH 4.6 throughout fairly quickly to keep it longer at room temperature (probably at least within 24 hours). It is not a brushoff but a fact that no one here has any practical experience with pickling fish at room temperature (or for that matter, at any temperature). We do not have USDA pickling or smoking for fish on our website or in the USDA canning guide, but there is information from Oregon State University we have shared on smoking fish.

I have pretty much relied on contacts in Alaska, or formerly in Oregon, for issues related to smoking and pickling of fish.

You also might find an actual food microbiologist actively researching with bacteria at Univ. of Wisconsin who knows more in detail of C. bot. patterns.

Thank you,
Elizabeth Andress


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