Botulism: not even once, banana edition.
May 14, 2016 11:24 AM   Subscribe

Is this banana jam sufficiently acidified by two tablespoons of lemon juice to make it safe to preserve in a hot water bath per the recipe? Or am I flirting with death?

On one hand, I've seen the pH of bananas at 4.5-4.7, which is on the cusp of what is acid enough to can, much like tomatoes that also need added acid. So maybe this recipe is plausible.

On the other hand, two tablespoons' worth doesn't seem like enough acid for this quantity, especially considering that bananas are denser than tomatoes.

I feel like I answered my own question (food safety: if you have to ask, don't do it) but I really like the concept of this recipe, and I've seen bananas in jam recipes from Ball and Pomona, though always in combination with something high-acid and some lemon juice. The process time on this recipe also seems kind of short for the jar size considering how dense bananas will remain even after cooking, but I'm mostly concerned about the degree of acidity.

This seems like one of those recipes that are safe until they're not, and I don't like those odds. I'm good at canning and could process jars in my sleep, so I'm confident about the factors that I control, but... is this a freezer jam only?
posted by blnkfrnk to Food & Drink (6 answers total) 2 users marked this as a favorite
 
As you probably know you need a pH of 4.6 or lower to safely water bath can anything. The only way to be sure a recipe is safe is by testing the pH. Testers are available for under $60. Or you can use strips which are cheaper but have stability issues if you don't use them a lot.
posted by Mitheral at 12:07 PM on May 14, 2016


Also the pH scale is logarithmic so you don't need much of something at vinegar's 2.5 to bring down the ph of something at 4.7 because the vinegar is 100+ times more acidic than the bananas.
posted by Mitheral at 12:14 PM on May 14, 2016


that jam is 1:1 with sugar. so i think the sugar will preserve things. see here (disclaimer: this water bath thing for jams is not something i am used to; it seems to be popular in the usa).
posted by andrewcooke at 12:16 PM on May 14, 2016


On the one hand, if it is an existing recipe that someone published, presumably they tested it and it is okay. On the other hand...it's something written by a food blogger, not a tested-in-a-kitchen-by-a-food-scientist type. Which...could still be okay, but still would be enough for you to have doubt in your head.

And it is that doubt in your head that is leading me to say "find another recipe." Even if everything actually IS fine, you're feeling nervous enough right now that even if you did go ahead and make it, something in the back of your head would always be wondering "but what if", and then you'd never have it because of your own paranoia, and then it becomes this albatross of jam on your shelf that you every so often look at and think that you should just go ahead and eat the god-damn stuff already but then you back off because "but maybe not" and then it just sits there for years taking up space and then you finally are all "well clearly it's no good now" three years later and you throw it out, and so what's the point?

Go with another recipe you trust more.
posted by EmpressCallipygos at 4:23 PM on May 14, 2016 [3 favorites]


I do not feel good about that recipe, for the reasons you have outlined very well. But really, pH testing strips are very, very cheap, and testers aren't much more expensive, so why not use them? You say you can process jars in your sleep, you wouldn't skip the full processing time right? So why cut corners elsewhere? I wouldn't.
posted by epanalepsis at 7:44 AM on May 17, 2016


Yeah, the fact that this is written by some random person-- even though it looks reasonable-- it why I'm fairly uncomfortable with it. "Nobody has died yet that we know of" is not enough for me to commit.

If anyone else is reading this-- so home pH testing for food safety turns out to be very difficult. pH paper strips are not accurate enough for food safety, plus over the long term in storage, pH will tend to rise and you need to know how much. It would take a lot of experimenting with a pH meter that I don't know how to calibrate over a lot of batches over time to get an accurate measure of what is safe in this context, and even then, I don't really know what I'm doing. And I don't care enough to find someone I can pay to do this. Also, everyone I mention this to thinks bananas sound gross as a jam concept.
posted by blnkfrnk at 8:09 AM on August 3, 2016


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