I'm sorry to keep bringing up issues like these! I know that bug reports are good and all, and there's a ton in this update to like... I've also run into some issues with brewing things in kegs. Sometimes, I'll get a result like this one:
I'm able to pick it up as an empty keg if I 'drink' from it, but it's happened a few times.
At the time, I was brewing Beer. I also just tried brewing kvass, on a hunch, and then shut down after saving during the 'brewing' day. The result was a Kvass keg with zero drinks remaining that I could fill a bottle once from, before it became the Empty Keg again.