Blog post: ecoli: Adventures in Sauerkraut - making kraut

So lets kick off this blog with some DIY fermentation!

So the way I'll structure the blog is to make a series of posts, putting together a fermentation project/experiment in with posts on published research related to microbes, fermentation process, related health and nutrition topics and whatever else I can think of. The goal is to keep things organized without making super-long posts and covering everything.

I've been getting into fermented veggies lately, and I've had some really good store-bought sauerkraut.. but the good stuff, with live cultures, is expensive. At a health food store nearby in Manhattan has a small bag of kraut for $10+ - which is just silly when all the ingredients you need are cabbage, salt, water, wild microbes and some time.

The basic recipe for this is adapted from Wild Fermentation, an excellent book by Sandor Katz, which I'm sure I'll do a more complete exposition on in the future. But since this is a science blog, not a food blog, I'm not going to simply blog about recipes... I am going to do SCIENCE!! This first experiment will be looking at the differential effects of store-bought cultures vs. wild microbes in a Manhattan apartment on cabbage fermentation - specifically in regards to fermentation time and sauerkraut deliciousness.

First I did my shopping at a farmers market - I purchased 2 heads of organic cabbage. Garlic scapes are the tops of garlic plants and seemed to be all over the market, and happen to be very delicious (halfway between straight up garlic and scallions in potency), so I decided to add some to the ferment.

Also shown is my pink Himalayan salt grinder, not shown is plain NYC tap water.

1. Chop cabbage and garlic scapes coarsely
   
2. Sprinkle salt and add to a big bowl. I haven't measured the salt here, so I'm mixing everything before packing into jars to make sure salt distribution is even between the jars. The salt pulls water out of the cabbage to make the brine and helps prevent growth of unwanted microbes, which can't tolerate the high salinity, and so prevents rot.
   
3. MIx and pack tightly into jars. I've used the bottom end of a beer bottle, since it fits snugly into the fermenting jar. But you want to try and force out as much air space as possible, which will prevent aerobic respiration and the dense packing keeps the cabbage from floating to the top of the brine.
   
4. cover the kraut (Sandor Katz recommends using a plate or a wooden fitting cut to size). But my beer bottle solution seems to work for the jars of my size. The point is to keep the cabbage packed in and weighed down (I've filled the empty beer bottle with water). Cover with a cloth - I'm using a cheese cloth - to keep out flies and dust. At this point I also added the commercial cultures to one of my jars.
   
5. After about 24 hours, the brine will rise, but you can also add salt + water if the veggies are not completely submerged.
   

Here's the setup after step 4

Hopefully everything is clear, even though I only have a crappy camera-phone. The jar on the left is the commercial cultures, the center jar is 'wild.' The one on the far left is extra cabbage so I added some of the extra brine and cultures just for the hell of it.

Here's the pre-kraut after ~24 hours.

The first results are in! Again, the jar on the right is with added cultures. The cabbage is much lighter in color, smells a bit more lactic and, though its hard to see from these pictures, is sitting lower in the jar. I'm assuming this is from early microbial action, causing faster fermentation. However, there's also the possibility that it was the extra salt and brine from adding the commercial cultures which has caused the cabbage 'bleaching', rather than the microbes. But I should be able to differentiate based on how long it takes the cabbage to ferment.

The next step is to simply add more salt water and let it ferment, so I'll keep the blog updated with new information.Read and comment on the full post