Fermented Cabbage

About six weeks ago, I started fermenting what I thought was a small batch of sauerkraut. The recipe was simple: cabbage and salt. I chopped the cabbage and massaged it with salt to release the water. I put it in a mason jar and weighed down the cabbage with marbles*, so that all the cabbage was submerged. The kraut has been fermenting in the mid 60s since.

I used a fairly high level of salt (and, stupidly, forgot to take notes), so the fermentation proceeded fairly slowly. After two weeks of fermentation, the kraut was only slightly sour. So I forgot about it for awhile. Four weeks later, I tasted it again. Delicious. Still not super sour, but incredibly complex. Interestingly, this batch turned out tasting distinctly Asian, with flavors of sesame, soy sauce, and anise, even though no such ingredients were added.

It turns out that adding more than 2-3% salt to a vegetable ferment favors different strains of lactic acid bacteria, characteristic of high-salt Asian ferments like tsukemono (Japanese pickles), soy sauce, and kimchi.

I like the result a lot, but it requires different pairings than normal sauerkraut. This experiment makes me want to try high-salt fermentations of more traditional Asian vegetables like daikon and bok choy.

*I do not recommend the marble technique. Although effective in weighing down the cabbage, they're a huge pain to remove whenever you want to sample the ferment. Zip-locs filled with salt water are much more convenient.

Malt Vinegar

If I'm brewing a high gravity beer with liquid yeast, one yeast vial does not provide enough cells for a proper fermentation. Rather than buying more vials, I propagate the yeast by adding it to a 1-4 liter starter of unhopped wort. If the starter is on the larger side, I typically decant the liquid and add only the yeast slurry at the bottom of the starter. This means up to 3 or 4 liters of unhopped beer down the drain.

While this decanted liquid is pretty bland on its own, it is exactly what malt vinegar is made from. Therefore, I've decided to start making my own vinegar. For the first batch, I added Bragg's raw apple cider vinegar to kickstart acidification, at a ratio of 1 part cider vinegar to 3 parts unhopped beer. For future batches, I will add samples from previous batches instead, so the cider content will be negligible after a few generations.

After decanting the liquid off the yeast and adding the cider vinegar, I let fermentation continue for two weeks in a gallon jug covered with tinfoil, occasionally swirling the jug to aerate. Then I transferred the finished malt vinegar to a swingtop bottle for longer term storage. This particular starter was fermented with a Belgian yeast (WLP570), so I'll be interested to see if any of the yeast flavors remain in the vinegar.

In the future I may experiment with adding oak chips or fruit to my malt vinegars. (Raspberry malt vinegar = delicious raspberry vinaigrette?) I could also add caramel or liquid malt extract to make darker, sweeter vinegar.