Making Malt Vinegar

Homebrewers spend a fair amount of time and effort preventing beer from oxidizing. But the best-laid plans don’t always work out, and every brewer — and beer drinker for that matter — has dumped out a beer that was neglected and left aging past its prime. You don’t need to dump that oxidized beer out, however — just let nature take its course, and with some patience you can have some tasty malt vinegar to use in your kitchen.

You can actually make vinegar out of any alcoholic fermentation — beer, wine, cider, sake, and you can even ferment a bit of fruit juice and sugar to make a fruit vinegar if you’d like. Vinegar is created when Acetobacter uses oxygen from the air to convert ethanol into acetic acid. For this article we’ll focus on beer, since as homebrewers we’ve all probably got some beer hanging around, but the process for making other vinegars is the same.


Do even a small amount of research about making vinegar and you’ll read about using a “mother” to turn beer into vinegar. A mother is simply a gelatinous disc of Acetobacter that will get your vinegar working faster. You can readily source one either from a local vinegar maker, or from a number of homebrewing suppliers. If you’ve ever made sourdough bread, the mother is the same concept as a sourdough starter, and similarly if you’ve made kombucha, the mother is similar to a “scoby.” Instead of using a pre-packaged mother, you can also seed your beer with active vinegar, such as unpasteurized (“raw”) varieties available at most health food stores. For example, Bragg’s apple cider vinegar is a popular choice to seed homemade vinegar and is readily available from many mainstream grocery stores.

You don’t actually need a mother or active vinegar, however, as Acetobacter is abundant in the air — hence why brewers take pains to prevent it getting into their beers by keeping everything clean and sanitized in the brewery. Relying on the open air to make vinegar without a mother just requires waiting longer for the process to work.


To make a 750-mL bottle of malt vinegar, you’ll need:

 A little less than 750 mL of homebrew. This is a job for a beer that’s maybe not your favorite, but is otherwise ok other than maybe starting to pass its prime — perhaps a growler that didn’t get finished. This isn’t a job for a prized New England-style IPA that you stood in line for at the brewery. On the flip side, a beer that has serious flaws other than just being exposed to air won’t make great tasting vinegar. Overly hoppy, roasty, or spiced beers are also not great choices — use a fairly neutral-flavored brew. English brown ales are classic.

 A vinegar mother or cup or so of “raw” vinegar. If you’re planning to purchase a mother, source one that is specifically for malt vinegar.

 A wide-mouth jar or crock that can contain your volume of beer and will allow a decent amount of surface area of the beer to be exposed to air.  Cheesecloth to cover the jar or crock (to keep flies out) and a rubber band or string to secure it.


1. If using a mother or unpasteurized vinegar, add it to the crock or jar.

2. Pour the beer into your vessel and aerate with pure oxygen or by shaking vigorously.

3. Cover the vessel with a few layers of cheesecloth secured with the rubber band or string.

4. Store the vessel in a dark, room-temperature spot until it tastes like vinegar. If you addedAcetobacter to your beer, this could take as little as three months. If not, this could take six months or more. This is actually the hardest part of vinegar making — waiting for the Acetobacter to do the work. Unlike fermenting beer, however, you can take the cheesecloth off whenever you want and take a sample out to taste, and you can even stir the vinegar to incorporate more air. When it tastes vinegary enough for you, it’s ready. Just be sure to keep the cheesecloth on when you’re not tasting to keep fruit flies out. It’s also a good idea to put your vinegar in a room that’s not the same as where you make beer — the less fruit flies you attract to your homebrewery, the better!

5. If you’ve used a mother, or if a film has formed on the top of the vinegar, remove anything like that, or pour the vinegar through fresh cheesecloth to filter out anything floating around — but don’t throw the mother away if you plan to make more vinegar; you can add it to your next batch.

6. Store your vinegar in a clean glass bottle with an airtight lid and use it liberally!

When you start getting towards the end of your vinegar supply, pitch some into a new batch of homebrew and start the process again.


Homemade malt vinegar is great for salad dressings, marinades, and for brightening up any dish that needs a boost of acidity. My personal favorite secret for taking an easy weeknight dinner to the next level is tossing some vegetables with a few tablespoons of oil, a few tablespoons of homemade vinegar, and salt and pepper, and then roasting them in the oven or in a foil pouch on the grill. Any recipe that calls for store-bought malt vinegar can be made with your homemade vinegar. It’s also great on fish and chips, of course. Here is a simple recipe for a malt vinaigrette, which can be used as a salad dressing or tweaked with some herbs and fresh garlic for marinades:



12 cup malt vinegar

12 extra virgin olive oil

1412 Tbsp. Dijon mustard

1 tsp. table sugar

salt and pepper to taste


Combine all ingredients in a mixing bowl and whisk together. Serve immediately. For better emulsification, you can also combine the ingredients using a blender or a food processor. Try adding two cloves of finely chopped fresh garlic to this recipe, plus some dried Italian seasonings to make a tasty marinade for grilling meats or veggies.

Commercially available malt mothers are available from many homebrew shops and online, and will speed up the aging process significantly.

Once you have gathered the materials, the actual process of making malt vinegar takes just a few minutes.

Malt vinegar can be made from any beer style, however it is best when made from beers that are not overly hoppy, roasty, or spiced.

Issue: November 2017