Probably one of the biggest differences between traditional pickling and fermentation is the addition of vinegar. Typically, the acidity in fermented vegetables comes from fermentation. Whereas vinegar is added to pickled vegetables to prevent contamination by molds, bacteria, and yeasts.
So, does vinegar stop fermentation?
The answer isn’t entirely straightforward…
Vinegar does stop fermentation, but only if in concentrations that are high enough to prevent bacterial growth. This is the case with traditionally canned pickles, salsas, and chutneys.
However, just adding a little bit of vinegar to fermented vegetables won’t be sufficient to stop fermentation.
When would you want to add vinegar to a ferment?
There are few circumstances when adding vinegar to a ferment is actually helpful.
1. For Added Flavour
Sometimes I add vinegar to a ferment for the flavor. Ferments usually end up at a pH of 4.5 to 3.5. Adding a few tablespoons of vinegar gives an added tanginess. I particularly like adding vinegar to fermented beets. It really helps to balance the earthy sweetness of the beets.
2. To Speed Up The Ferment
Certain lactic bacteria are acid-loving. For example, sauerkraut starts out with a ton of different bacterial cultures, but by day 5, the acid-loving lactic bacteria have taken over.
By adding a bit of vinegar to a ferment, it creates an environment that is ideal for acid-loving bacteria, thus speeding up the fermentation time. While fast fermentation isn’t always the goal, it can be helpful in preventing unwanted contamination in a ferment that is going to be stored for a long period of time.
My favorite fermented cucumber pickle recipe uses a little bit of added vinegar to ensure a good, fast ferment.
3. As a Culture for the Ferment
Cultured vinegar is perfect as a starter for fruit ferments. While most vegetables will readily ferment on their own, fruit is prone to yeast and mold. So using vinegar as a starter will ensure a quick and successful ferment. I’ve also used vinegar to culture things like salsa, relish, and chutney. Really, anytime you want a quick ferment, you can use a starter.
Not all vinegar will work as a starter. Here are a few options:
- Homemade fruit vinegar
- Raw and unpasturized apple cider vinegar (affiliate link)
- Sour and unflavoured kombucha is very similar to vinegar
I really enjoy making dill fermented green beans. But they’re never quite Dilly enough for me. Would it be a problem to add pickle brine after the fermentation is done and I’ve put them in the refrigerator.. Would that ruin their refrigerator life ?
I’m guessing that you’re asking about adding commercial pickle brine from vinegar pickles to your fermented green beans? Depending on how much you add, it probably won’t kill the fermentation. I also like a bit of vinegar in my fermented green beans. It just gives them that extra bit of tanginess. So I ferment beans with a small amount of vinegar. Cheers!
HI Emillie,
do you by any chance know, at what PH an active fermentation stops? I would like to make a hot sauce and add vinegar at the end to stop the fermentation, so I can add sugar to the sauce without it being eaten by the bacteria and restarting the fermentation process…I don’t want to use sugar alcohols for the sweetness and also don’t want to boil/pasteurise the sauce to keep the good bacteria alive…any suggestion would be much appreciated.
Kind regards 🙂
It requires a pH below 4.2 to stop fermentation. That’s probably too acidic for your taste. It is hard to add sugar to something without having it ferment away! When I want to keep something sweet, I stash it in the fridge. That works for 2-3 weeks. For longer than that, I freeze the ferment. In fact, I pretty much always do that with hot sauce anyway! We don’t use it up very quickly, so I freeze it in 1-cup mason jars. Hum… I can’t think of another way to stop fermentation without killing the good bacteria. Cheers!
Thank you so much for your reply 🙂
My PH was 3.6 after adding Mango and I hoped the low PH would not allow any further fermentation, but it continued to ferment (in the fridge). I don’t want to freeze the hot sauce since this would also kill most of the good bacteria. I will now try to add mango at the beginning of the fermentation and add Stevia at the end for sweetness…lets see 🙂
Wow! That’s a pretty low pH… I’m surprised it was still fermenting. I don’t think freezing will kill all the probiotics. I actually use my freezer to keep my cultures alive! I have koji rice (for miso), cheese cultures, and yogurt cultures in my freezer at the moment. I usually don’t keep them for more than 6 months, but they seem to be good for at least that long. Cheers, Emillie