How long do homemade olives stay safe?
Hey Tildes food crew!
I made some olives 3 years ago and kind of a "set it and forget it" situation. And well, I forgot them for too long. It's been 3 years now and I've only found them because I was looking for jars for a new batch. I opened them up and didn't hear any "hiss", they smell good, there is no sign of mold (on the 2 good ones I'm keeping, we did lose one jar to mold), and I did a small taste test and they tasted olive-y and good. They have been in a cupboard for the entire time and I'm happy to share the recipes if that is helpful. The olives in each were slit to facilitate faster edibility. They both have a 5% brine, one with red wine vinegar and the other with balsamic vinegar.
I know we have quite a few crafty, homesteady, foody folks here and would appreciate any advice you can provide! Just making sure they are still safe to eat! Thanks!
Don't have any experience with making olives, but https://stilltasty.com is a pretty good resource and it gives the best before date for an open can of commercially canned olives as 18-24 months and for deli counter olives in oil as 1-2 months.
Also see FoodKeeper by USDA - it only suggests storing olive bar olives for 2 weeks.
They also all assume storage in the fridge, and you say your jar was just standing in the cupboard, so it's probably less than that.
However, those are estimates for the best quality, and the StillTasty page also says this:
So I'm guessing it's very much a "at your own risk" situation. They're way past the suggested best before date, especially since you didn't store them in the fridge - and you did find mold in one of the cans, which means the time and conditions were clearly enough for it to develop. But you also say you didn't find anything strange in the other cans, so they may be safe to eat for now. I wouldn't - but I'm also much more paranoid about food safety than most people out there.
Edit: turns out StillTasty has an email address for food safety questions, so maybe you can ask them as well! Seems like they actually answer them
The 2 weeks is for basically tossing the olives in a fridge isn't it? (no vinegar or brine)
Yeah, that's true. Brine would extend the life, but also not keeping them in the fridge would shorten it. It's probably very hard to figure out the safe shelf life here.
Thanks for the feedback! I'll be going with some other advice and testing the PH levels. There might still be some "at your own risk" but at least not Botulism!
"At your own risk" is probably the proper response. Canned olives should last 1.5 years. Personally, the use of vinegar reduces the risk enough for me. I'd be more worried they'd taste like cardboard since some things lose their flavor after a few years.
I'm a bit curious how the mold grew. Were the olives not completely covered, the vinegar too watered down, or was the mold just on the surface of the vinegar?
I think there may have been some headroom on top. I had weights on the olives but they ended up moving into the middle so the top ones were exposed. Weird as it still had an oil barrier, but who knows. The mold was just on the surface.
One tastes a little bland, the other is surprisingly good (from the test tastes I did)
I discovered this guide to food safety a while ago, and found it really helpful to understanding how food safety works.
In your case, there's not enough information to go by the numbers since you don't specify PH, vinegar ratio, or canning procedure. The 5% brine matches a water activity of ~.97, or not a major contributor to food safety in this case.
I second this comment. I worked in the spice industry for a few years and had to deal with storing a variety of spices in a way that kept them safe for human consumption. Buying some pH test strips and making sure the acidity of your homemade olives are within an acceptable range will be your best bet for keeping them safe to eat.
Mine is a 5% brine and quarter cup of vinegar. I followed this recipe.
I will also be doing the PH test tomorrow!
I wouldn't eat it. The recipe is a little bit sketchy in how there's no sterilization step, and the recipe itself suggests one year max.
On the other hand, people have eaten much sketchier things and been fine.
Olives are outside my expertise, but microbial stability is incredibly important for winemaking. I can’t give you a definitive answer, but I can give you some information.
First, some olives are apparently brined, not fermented. A short internet search suggests the brining method involves salt and ph neutral water. Since yours are in vinegar, they likely used one of the methods that involve fermentation. Can you confirm? Also, it may have involved fermentation even if you didn’t know you were fermenting it. I made a fermented garlic paste that involved putting garlic through a food processor, adding some salt, and leaving it out for a few weeks. This is a lactofermentation, which is one of the most common types of fermentation (excluding alcoholic fermentations).
If your olives are brined, I can’t help you. But if they are fermented, I can say they are probably safe. Food doesn’t just « go bad » on its own. It can oxidize through contact with the atmosphere or get exposed to a microbe that can grow on it. Honey famously never spoils. This isn’t because of some special property of the honey. It is just that no microbes exist that can digest honey. As soon as one evolves that can digest honey, it will start spoiling. That is the same reason plastic never breaks down.
This type of fermentation is completed by a bacteria called lactobacillus. They ferment the single ring sugars into lactic acid. They do this because it provides energy, and because it makes the environment less hospitable to other microbes. On an evolutionary scale, if you can kill all the competitors you have a huge advantage. This is also the reason why yeasts produce alcohol from sugars: most microbes can’t survive in alcohol.
I don’t know the process for making olives, but many fermentations just add the items to a solution of vinegar and salt. This creates a solution where lactobacillus can flourish and most other microbes can’t grow. Fresh crops are like a ball at the top of a mountain. They could roll off in any direction. We just push the ball in the direction we want, and natural processes will take over. The vinegar is just this first push in the right direction, allowing our preferred microbes to take over instead of a different one.
There are only two microbes that can survive in finished wine: brettanomyces and lactobacillus. For Brett, we just try and make sure the wine is never exposed. For lactobacillus, we add preservatives to prevent it from being able to survive. But for both of these, they never make wine unsafe to drink. Spoiled wine is never unsafe, just unpleasant. I don’t know if the same is true for fermented olives, but I would imagine it is.
So here would be my recommendation: if they look good, smell good, and taste good, they are probably fine. The human body is pretty good at telling us if things are bad by having them smell or taste bad. It can fail at times (stinky cheeses smell bad but aren’t). But it is still pretty good.
My meadmaking would like to disagree with you here. It is mostly because the sugar to water ratio is too high and it acts as a dessicant. Honey doesn't spoil as long as it can't suck water from somewhere and get that ratio low enough for microbes to survive.
To throw in another honey-related brewing anecdote: I commonly use honey as my bottle carbing sugar.
For anyone unfamiliar, one method for carbonating hard cider and such is that you bottle it while there are still some fermentables left. This causes some fermentation to happen in the bottle, but since this new co2 can't escape it ends up dissolved as carbonation. This method may sound dangerous, like you're building volatile bottle bombs, since it would be difficult to know exactly how much more fermentation will occur. The solution is to wait until the original fermentables are all gone and then add in a small known amount of new fermentables right before bottling. I use honey for that, although I think it's probably more common to use brewing sugar or carbonation drops.
That is what I was going for, but I didn’t phrase it very well. I should have phrased it like « there are no microbes that can digest honey within the chemical matrix of honey ». There is no fundamental reason a microbe couldn’t evolve to handle the matrix of honey. Saccharomyces cereviciae, the yeast that ferments wine, beer, cider, mead, and bread, originally could not handle more than a few percent alcohol. As it has been domesticated by humans, it can handle much higher alcohol. Alcohol laws in the US after prohibition had a higher tax on wine above 14% because anything higher was fortified, since yeast would die around 14%. But today we have yeast that can ferment reliably up to 15 and 16%.
Confirmed. I used a 5% salt mixture with a quarter cup of vinegar from this recipe. We picked the olives from the same orchard.
I have mostly been taking your approach - they look, smell, and taste good. So I think they'll be fine. I will be testing for PH to make sure there isn't any Botulism.
I make wine too, and mostly got into because it's so hard to mess up. One of the guys who picks up grapes at the same harvest as me once said "the Germans make beer because everything has to be precise - cleanliness, temperature, timing, ingredients, etc. The French make wine because it's all good feels and vibes. You can't really mess it up!"
Eat at your own risk and all that, but if you already had some of it, and haven't started to have diarrhea or worse, it's probably fine, or at least it probably doesn't have botulism.
Especially if it's still acidic. Botulism doesn't like acidity. For acidic + salt preserves, the main thing that'll get to it is mold. The main thing to worry about is botulism, since that can be hospitalizing, although that's more common with canning.
At least I would probably slowly phase it in, and not like devour them immediately.