Mamey has a pH of 5.7. Ripe Mango is 5.8 - 6.0 and Papaya is 5.2 - 6.0. As all these fruits are low acid for canning purposes, any preserve using them has to contain sufficient lemon or lime juice to raise acidity to a safe level.

The other option is to freeze any preserve or make small amounts and refrigerate.

Carol

Thanks Carol,
So these aren't as acid as peach and I'll need to add more lemon juice = RealLemon

Do you have any idea how much?

Something like 4 tbs to a cup of fruit?

Does that sound right?

Thanks again
Corrie

FAIK there is no tested recipe for canning any of them so the amount of lemon needed would just be guessing. They are all considered freezer jams or as Carol said, small amounts refrigerated.

It is similar to the question about the squash jam - they are basically low acid 'butters' and so not approved for canning because of the pH and the density.

Only other possibility would be if there is a recipe for one of them in one of the niche cook/canning books and those are do at your own risk.

Best bet is to make and just freeze them.

Dave

Strawberries are around pH 6 also.
I think if I follow the strawberry preserves recipes, which call for added lemon juice....
...I should be good to go

Knowing the pH of those fruits helped a lot!

Thanks guys
Corrie

Strawberries are an acid fruit - 3.0 to 3.9 - and most recipes for strawberry jam do not call for added lemon juice. When they do it is for added gel/set, not acidification.

What is the source of your pH 6 for strawberries? That is the soil pH recommended for growing but not the pH of the berries themselves.

If you feel you are "good to go" then you do so at your own risk.

Dave

Here is a link that might be useful: pH of Foods and Food Products

Sorry Dave, the search function between my ears stopped working years ago...
I was thinking another fruit and typed strawberries by mistake.....because that was the last thing I looked at!

Anywho, searching around, it seems that the only things to worry about are sugar and acid.

What in this world would be the difference between canning a high acid fruit......or canning a low acid fruit, that you add lemon juice to it and make it acid?

Thanks
Corrie

What in this world would be the difference between canning a high acid fruit......or canning a low acid fruit, that you add lemon juice to it and make it acid?

The big difference in the nature of pH. pH is exponential not relative. Each tenth of a point is 10x the difference, each whole point (5 vs. 6) 100x different. It would take a he** of a lot of lemon juice to take something with a pH of 6.0 down to the minimum safe pH of 4.5-4.6.

EX: If it takes 1 T of lemon juice to make a pint of 4.7 tomatoes safe at 4.5 it could theoretically take you approx. 150 T to get from 6.0 down to 4.6. An extreme example I know but you get the point - you'd just be guessing how much lemon juice was needed with no way to know for sure and the end result would likely be inedible.

Freeze it.

Dave

I have some recipes for safe sources but I'm just leaving town so will have to post this evening.

Meanwhile, there should be a mango jam with lime and rum (optional) I posted some time ago. See if a search brings it up.

Basically anything above 4.6 is considered high-acid and when sealed by processing offers the potential for botulism. It's very common for home preservers to be unaware that there are fruits out there which are low-acid and do present risk. Aside from the tropical fruits you inquired about, bananas and melons also fall into this category.

People assume sweet preserves don't present risks. That's a false assumption, though it is true sugar mitigates the risk somewhat.

Carol

Thanks Carol, I searched, even google gardenweb, but couldn't find it.

I did find something out about mangos though. They get more acid as they get ripe. A green mango, like for salsa, is a higher pH, around 5.8 - 6.0 like you said.
But a ripe mango, like for preserves and jams, has a much lower pH, 3.4 - 4.8. That would only take a couple of tsp of lemon juice.

Here's one of the sites that lists the difference, there a lot more:

Here is a link that might be useful: pH level of foods

I am sorry to say that the pH numbers of mangoes, ripe and green, are erroneous. The NCHFP is very specific that in salsa, for example, green or unripe mango is to be used as opposed to ripe mango because the ripe is less acidic.

I've always assumed that the FDA somehow transposed the numbers on their pH list and that error has not been corrected.

Even the Ball Blue Book has occasionally had editing errors.

To quote one biotechnology journal:

A study of the acidity of the pulps indicated that pulp obtained from pre-ripe fruits were generally more acidic (pH 3.50 to 3.85) than those obtained from ripe fruits . . . Effect of ripening on the composition and the suitability for jam processing of different varieties of mango, Kansci et al.

The Virtual Herbarium (affiliated with Florida Atlantic University and Miami University) says PH: Fruits with a pH of 4.0 to 4.5 (such as mangos, papayas, figs) should have acid added to packing medium to obtain a pH below 4.0. One-fourth cup lime or lemon juice per pint is enough to make the needed pH adjustment.

Because slightly underripe fruits have higher pectin levels, they are often preferred for jams. In that case, the pH may be somewhat lower than if one used dead-ripe fruits, which will be at the higher end of the pH spectrum. The improved setting qualities and higher acidity are why slightly underripe fruit often is recommended for preserves.

Variety of fruit and growing conditions, including such factors as hours of sunlight exposure, affect pH levels, so there can be considerable variation from garden to garden and season to season.

Mango-Lime or Mango-Orange Jam

2 pounds peeled and diced mango
1/2 cup lime juice or 2/3 cup orange juice
2 3/4 - 3 cups sugar

These proportions are from Linda Ziedrich in The Joy of Jams, Jellies and Other Sweet Preserves.

Carol

Here is a link that might be useful: Mango with Rum Option

Now I'm really confused......

Dave said: "down to the minimum safe pH of 4.5-4.6. "

and these guys say:

Effect of ripening on the composition and the suitability for jam processing of different varieties of mango (Mangifera indica)

"A study of the acidity of the pulps indicated that pulp obtained from pre-ripe fruits were generally more acidic (pH 3.50 to 3.85) than those obtained from ripe fruits where the pH ranged between 3.91 and 4.35 (Figure 3c)"

I think mangoes can vary...and what I need to do is bring one of my pH pens home and test it...and test it again after it's canned for a while....before we eat it.

Here is a link that might be useful: research paper

Typically commercial processors will aim well below the 4.6 pH number for a guarantee of safety, thus the recommendation from Florida for sufficient acid to reach 4.0. Things happen even during storage and pH numbers can change, so 4.4 pH, say, is just too close for comfort.

I think Dave misspoke. It happens when you're typing, and pH numbers are counter-intuitive as the numbers go up as acidity goes down. So what he probably meant to say is down to the maximum safe pH of 4.5-4.6.

You can do whatever you like. We've answered your questions and spent a good deal of time doing it.

Carol

my goodness....
Thank you, I think I will

I think Dave misspoke. It happens when you're typing, and pH numbers are counter-intuitive as the numbers go up as acidity goes down. So what he probably meant to say is down to the maximum safe pH of 4.5-4.6.

Indeed I did. My apologies. Thanks for catching that Carol. Not only the typing issue but sometimes my frustration over beating a dead horse gets in the way of my fingers.

Corrie - as we have said, per the standard canning guidelines you cannot safely do this. This doesn't mean you can't do it - of course you may can anything you wish if you are comfortable with the associated risks. But we aren't going to tell you it is safe to do because according to the accepted guidelines, it isn't.

You asked and we answered. I'm sorry we weren't able to convince you and that you aren't happy with the answers you got. But if, for some reason, you feel that canning these preserves is really that important despite the risks then by all means go for it.

Dave

Good grief...you both sure read a lot into something that's not there.

I'm discussing something, and now the two of you are beating dead horses, spending a good deal of time, and frustrated.....

..only because someone asked questions

And the whole time, you're posting conflicting things

It's not conflicting so much as complicated, particularly discussing issues online. There are too many opportunities for misunderstanding.

The complication arises from the fact that there are many variables and that anytime one steps away from lab-tested recipes (Linda Ziedrich's formula which I posted online is a vetted recipe.) there is a certain degree of risk.

This is particularly true for any home preserver with limited experience. It's the old Socratic You don't know that you don't know.

I think both Dave and I have tried to be clear, but that may not have been the case. You can follow Ziedrich's proportions. As all the fruits you mentioned fall generally within the same pH range, that acidity should be sufficient. Should is the operative word as I can't test what you've proposed.

For total security, the Florida recommendation of One-fourth cup lime or lemon juice per pint is certainly sufficient and offers plenty of leeway.

There are lots of threads on this forum regarding pH meters and some of the issues.

Carol

Carol, yes, it gets very complicated when you first say mangoes "Ripe Mango is 5.8 - 6.0" and then in a later post say "PH: Fruits with a pH of 4.0 to 4.5 (such as mangos, papayas, figs) should have acid added to packing medium to obtain a pH below 4.0."

and I won't even get into Dave's "he** of a lot of lemon juice"
"minimum safe pH of 4.5-4.6. "
"sufficient acid to reach 4.0"

It wouldn't be so complicated.....if it wasn't so conflicted

Well anywho, here's the skinny on my mangoes.

I started out with very ripe, about to go bad, mangoes.
Stuck a pH probe in them and got 3.8 pH.
Finished cleaning, peeling, and preping them, and got pH 3.8 again.
Boiled them, and got pH 3.8 again.
Finished them off for canning with sugar and I went on and added 1/4c Reallemon per pint, can't hurt.

I realize you're both trying to help....but dismissing and trying to lay the blame on someone else, is not helping.

Corrie

No one is dismissing and no one is laying any blame. The complexity, what you call conflicting information, is due to a basic lack of understanding of the context in which the info is given. And we often make the mistake of assuming that the reader has that basic understanding.

In this case that is understanding the differences between acid foods and low-acid foods and how they may be dealt with in the context of canning. With that knowledge the terms maximum vs. minimum, up to vs. down to etc. make sense.

For the purposes of canning, a pH of 4.0 is considered the maximum, upper, borderline of natural safety in a food. Lower (below 4.0) is better, higher than that (4.0) is risky and requires additional acid. How much acid is required has to be determined by lab testing - not by guessing, or assuming, or litmus paper, or any other in-home testing.

It is further complicated when you note, as Carol pointed out and you had discovered, that multiple sources will quote you multiple different pH for mangoes and for mangoes in various stages of ripening. In the context of home canning only the USDA/NCHFP measurements count, not the many other sources one can dig up on the web.

Depending on the natural pH of the food in question the amount of added acid that is needed may be so much so as to make the food unpalatable, in other words a he** of a lot.

That same 4.0 is also the minimum that the low-acid food must be brought down to for safety when dealing with foods that have a natural low-acid (alkaline) pH.

pH in canning is not that same thing as pH in soil or other applications where 7.0 is neutral and 7+ is alkaline.

For all these reasons plus the density and cold pockets issues, and for purposes of any others who may read this thread and assume canning these 3 fruits in such a manner is safe to do, USDA/NCHFP labs have determined that they should NOT be canned as a preserve/jam/butter (your original question).

Is this conclusion disputed? Sure. Some dispute it based on the variance in pH info, some on the density issue, some on the amount of acid required, some for the resulting quality, etc. So in the end while it isn't recommended you take the risk of canning them, it is your choice, your risk to take.

Dave

"No one is dismissing and no one is laying any blame. The complexity, what you call conflicting information, is due to a basic lack of understanding of the context in which the info is given. And we often make the mistake of assuming that the reader has that basic understanding."

First Dave said Jan 13, 12 at 15:06: "down to the minimum safe pH of 4.5-4.6"

...Now Dave says: "a pH of 4.0 is considered the maximum, upper, borderline of natural safety in a food. Lower (below 4.0) is better, higher than that (4.0) is risky and requires additional acid."

Dave, your context sux...........LOL

I asked a simple question, just give a simple answer....
...and only one answer

That would stop a lot of the confusion

Thanks again
Corrie

Note I said NATURAL safety, the natural pH of the food, even underlined it.

You are comparing two different things - the natural pH of a food itself to be considered safely acidic and the pH of a food that has been acidified down to a safe level.

Try reading more carefully to eliminate some of your confusion.

Dave

I got it the first time Dave....
First you said it would take a lot of lemon juice to take it down to the minimum safe pH of 4.5-4.6....
...then you said the minimum safe pH was 4.0

...in between you gave a lengthy explanation of how pH is logarithmic

You just said "natural" for the first time LOL....why didn't you say "natural" when you said "minimum safe pH of 4.5-4.6."

You wouldn't be moving the goal posts on me would you Dave? LOL I can't read 'more carefully' something that's not there.

You didn't say a word about how my ripe mangoes tested, or even ask me how it turned out?

Corrie