Why Vinegar is Unnecessary for Making Kombucha

Have you seen a recipe for Kombucha that says you need to add vinegar? Why would you need to do that? Does it make the brew stronger? These and many other questions about vinegar and Kombucha often fill our inbox.

While there is a lot of conflicting information about vinegar and it’s easy to get confused, the short answer is NO you do not need to use vinegar, either as starter liquid or in your vessel.

However, there are some situations where vinegar can serve as a useful brewing tool, assuming the correct type of vinegar is used. Below, we’ll review exactly when and when not to use vinegar with your Kombucha brew.

How Do Kombucha and Vinegar Relate?

Kombucha is an acetic acid ferment, which means it belongs to the vinegar family. The bacteria in both are generally related but different in type and mix, while the yeast differ greatly.

Vinegar is technically defined as having 4-8% acetic acid content. By contrast, Kombucha contains just 0.5-1.2% acetic acid. We do not need to dilute Kombucha in order to enjoy it as a beverage, making it an “easy drinking” tea vinegar. The acetic acid provides a delicious flavor punch as well as a host of other benefits.

Should I Be Using Vinegar for Kombucha Starter?

No!

Let’s be crystal clear right up front: despite what you may have read or heard, vinegar should never be added to Kombucha as starter liquid. Use only well-fermented Kombucha as starter liquid for your brews.

There are a wide variety of recipes out there, and some recommend adding vinegar to the brew to act as starter liquid or to help prevent mold. There are many reasons why this outdated advice should not be followed, but the most compelling is that adding vinegar results in a poor tasting brew.

Beyond that, it’s possible that vinegar will permanently alter the balance or cause contamination. While it may provide a measure of protection from mold, vinegar cannot contribute to the flavor or overall health of a brew or SCOBY.

Instead, for starter liquid always use unflavored Kombucha from the top of the previous brew or from a healthy SCOBY Hotel, preferably at least 2 weeks old but not more than 3 months without refreshing.

*Note: In a pinch, it should be possible to use flavored Kombucha as starter for one batch, assuming there is nothing else available. An increased chance of mold may exist based on the flavorings, so watch the new brew closely for any issues.

Why Do Some Recipes Call for Vinegar to Be Added to Kombucha?

Occasionally you may come across an older recipe for Kombucha that calls for the addition of as much as 1 cup of vinegar in place of starter liquid. Other recipes may tell you to sprinkle just a few tablespoons of vinegar to the top of the brew each time after adding the SCOBY. These bad recommendations are simply left over from the pre-internet era when fears around mold and contamination led to overzealous practices.

There is another situation where using vinegar is often included in the instructions: dehydrated SCOBYs. While increasingly rare, there are some vendors that still offer a dehydrated Kombucha culture, and the first step in the directions is generally to soak the culture in vinegar, as well as use vinegar in place of starter liquid when you brew. As explained in more detail here, dehydrated Kombucha SCOBYs should be avoided as they produce a poorly flavored brew that often goes to mold and rarely births another SCOBY: Problems Brewing with Dehydrated and Refrigerated SCOBYs

No matter the reason, a recipe or culture that calls for vinegar to be added to the brew is generally one to be avoided.

Is There Ever a Time to Use Vinegar with Kombucha?

As with everything in life, there are exceptions where using vinegar may be acceptable when making Kombucha. One such situation is if you wish to “cure” the vessel or equipment prior to brewing.

Curing means using a small amount of vinegar to coat the inside of the vessel or the utensils, then pouring the remaining out. The purpose of curing is to rinse away any residue in a powerful yet natural disinfectant while also setting the pH of the surface of the vessel and utensils. The low pH of vinegar is what helps protect against contamination and therefore mold.

Here’s the thing: you can also use well-fermented Kombucha to cure your vessel or utensils! So as long as you have extra Kombucha on hand, you can use that instead of vinegar. If you only have one cup of Kombucha to use as starter liquid, and you need to cure the vessel also, then in that case vinegar may be the only option.

Why Cure a Vessel with Vinegar or Kombucha?

To be clear, curing is an optional step that need not be taken if the vessel and utensils are clean. As long as you use the right type of vinegar, there’s nothing wrong with these additional safety measures, and we demonstrate them in our videos so that people may see how it’s done.

One example of when curing is recommended would be if you decide to use chemical sanitizers (such as SanStar (AMZ) which is used by beer brewers) or think there may be some residual grease or soap residue on the vessel, spigot or equipment. In that case, curing with well-fermented Kombucha or distilled white vinegar prior to brewing is recommended for best results. Or if your jar had mold in the last batch, after cleaning the jar with soap and rinsing well, you might also choose to cure.

However, under normal brewing conditions, using a clean vessel, a healthy SCOBY, and sufficient starter liquid, vinegar is never needed when brewing Kombucha. Millions of people around the world brew successfully without ever using vinegar. Click Here for more Kombucha Brewing Safety Tips

*Note: If using an Oak Barrel for brewing Kombucha, curing is done via Barrel Sanitation Tablets such as these rather than vinegar or Kombucha.

What Type of Vinegar to Use for Curing a Kombucha Vessel

If you decide to use vinegar, it’s important to only use distilled or pasteurized white vinegar (THRIVE, AMZ) (preferably organic so as to avoid GMO corn). NEVER use raw vinegar of any kind, as the natural microbes present will disturb the balance of the brew.

We also generally recommend against using apple cider (THRIVE, AMZ) vinegar of any kind, which can often have living organisms in it even if not labeled explicitly as “raw,” sometimes including vinegar eels, which are harmless to humans but will ruin the brew. If using vinegar, stick to white distilled/pasteurized for best results.

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So while Kombucha is essentially “easy drinking tea vinegar” it is now clear why adding vinegar is not only unnecessary but sometimes leads to a less delicious Kombucha or even a contaminated brew, including mold. Following the best practices provided in this post and detailed in THE BIG BOOK OF KOMBUCHA will provide brewing success for years to come.