I’m a little obsessed with yeast and bacteria right now. They’re responsible for tangy butters, bread, yogurt, cheeses, and all sorts of other delectable foods. I’m a little disappointed at how much of the info about this on the web is just a cut & paste repeat from one site to the next, so here’s my attempt to add a little more usefulness.
Butter: I’ve been doing cultured butter from the directions at The Traveler’s Lunchbox for a couple of months. If you have any kind of electric mixer, it’s not much work, and the result is rich and yellow. Commercial butter seems anemic in comparison.
Bread: I had a sourdough starter in college, one I did from scratch in my own kitchen. The bread it made was tasty, but very dense. I forget what happened to it, maybe died from neglect? I’m trying again, this time using buttermilk along with flour and water to give it a kick-start. I found recipes for this online, but nothing else along the lines of “I tried the recipe and [stuff] happened.” I’ll try to remember to report back later in the week, when I see if it’ll properly leaven bread. If it doesn’t work, maybe I’ll try a potato water version. Or I could ask around for a batch of starter, but it seems more fun to make my own.
Cheese: I really like paneer and other fresh cheeses, so with all the buttermilk I have on hand I’ve been making batches of my own. You take milk (I do a half gallon) and a glop of buttermilk (I don’t measure—probably 1/3 to 1/2 cup) and heat the mixture until it curdles. It’s a little slower than vinegar cheeses, and creates a softer curd. This is delicious mixed with jam in crepes, or with pasta. I wonder if I could inoculate it with blue cheese mold… that might be an upcoming experiment too.
Yogurt: I can’t walk into a Lebanese restaurant without ordering the labneh, aka yogurt cheese. It’s one of the best foods ever. It’s also really easy to make as long as you have real yogurt (milk + ‘active cultures’, with no sugar, gelatin, flavorings, or other crud). Put a coffee filter in a funnel, dump the yogurt in, and let it drain overnight in the fridge. Next I’m going to try making my own yogurt from scratch. What I really want to experiment with, though, is different regional yogurt cultures. Like with sourdough, yogurt-making bacterias exist in a variety of different sub-strains, with various effects on the yogurt’s taste and texture. Sourdoughs International provides a wide range of cultures for breadmaking, but I haven’t found the yogurt equivalent.
You could get really worked up about food safety with these kinds of experiments, but if you’re using pasteurized milk, clean dishes and utensils, etc. and not letting goop sit around without your friendly bacteria in there working, it’s pretty reliable. Use smell, taste, and texture to keep an eye on what’s happening. Healthy cultures are tangy and bubbly.