Wednesday, December 23, 2009

Update On Making Malt Vinegar

On June 29, 2009 we wrote a post on an experiment we decided to try, making malt vinegar. Here is an update.

Between June and September we looked at and smelled the "vinegar" every few weeks, things were looking good.

On September 26th the one with the bread had some mold on it, so we removed it and put the liquid into a clean jar. The other looked fine.

On October 25th we took off more mold and decided to add some apple cider vinegar "mother" to it, hoping that the mother would get the vinegar going.

By November 29th the whole thing was moldy so we threw it away.

The jar that did not have the bread still smelled fine, but just like stale beer. We decided to add some mother to that as well in hopes that it would get the vinegar process started.


  1. 1. you're best off using a low-hopped beer/ale.
    2. temperature is important -- too cold (less than 70 in my experience) and the vinegar bacteria won't out-grow other stuff and you get mold, too hot (over 90) and you get the same thing. I've found 80 or so to be about perfect.
    3. oxygen (air) is essential!! Commercial systems almost always have aerators going full time to speed things up. you want to shake your beer up a lot to get the co2 out and the air in. after that you want a container that has allows a large surface to volume for your vinegar vessel.
    4. I've never done this with commercial beer,
    5. Most ales really don't have enough alcohol to produce a long shelf-life (acidic) vinegar. You'll get 3-4% acetic, commercial varieties are all 5%. You can (!) taste the difference, some like the milder. If you know a homebrewer (or you're doing your own, do a special high alcohol batch, some for winter warmer; some for vinegar) -- shoot for 7% ABV or more.
    6. Note that once all the alcohol is converted to acetic acid, the same bacteria will switch metabolism and begin to consume the acetic acid (i.e. your vinegar will become water if you leave it go) -- so either refrigerate or briefly cook to kill the mother (save some for your next batch).

    At the right conditions you should see a mother (film across the top that looks a lot like raw white chicken meat). in less than 2 weeks.

    jeff knaggs --

  2. Jeff, Thank you for all your info. As you can tell the malt vinegar is a new experiment for us and we really had no idea what we were doing. We've had great luck with ACV and hopefully with all your tips we can achieve a good malt vinegar.

  3. Interesting to read about your experiment - I've never tried to make vinegar!

  4. It's a lot of fun...when it comes out well!

  5. Just an update on the other jar we started. 1/18/2010 we looked at that jar and it was all moldy, as well. I am going to have to follow Jeff's advise!