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