Monday, January 2, 2017

Yeast

I've always thought that yeast is boring. I mean, you take it out of a bag--boring. It's a uniform color and it makes bread rise. It's also a finite commodity--in an emergency, once it's gone, it's gone. But there's yeast in the air all around us. I've investigated capturing wild yeast but it's a long drawn out process and takes lots of resources--if you're baking bread every few days great, but if you get a strong culture it grows so fast that anyone else can't use it all and it dies. Or you keep feeding it and use all your flour just keeping the thing alive.

Then I ran across a mention of using fruit yeast. The white bloom on grapes, plums, etc? Yeast. There's yeast on every fruit and every bark and every leaf, just waiting. If I can harvest yeast that easily, then why bother keeping a culture alive? Start a new one every month or so.

I didn't have any fresh fruit to test my hypothesis (aside from oranges) so I used raisins from last year's harvest, a dried plum from last year's harvest, a piece of dried apple from two years ago, and a piece of fresh orange peel.


After four days bubbles were starting to appear in the water, and three of the four smelled "yeasty." The plum just smelled fermented. The raisins and plum had fungus hyphae in the water.


I took 1/4 c of flour and 1/4 c of filtered water and put them in jars with about 2 teaspoons (8 ml) of liquid from each bottle.

Less than 24 hours later the dough was already rising. The strongest (most bubbly) was apple, followed by raisin, orange and plum in that order.



Plum had bubbles but hadn't started mounding yet. I fed them another 1/4 c of flour and 1/4 c of water, put them in larger bottles and put them away again. The orange had a sour orange smell, the apple just a faint hint of apple, the plum just smelled like fermented plums, and the raisin like raisins. All had a yeasty smell. At this point I had cut out a week, possibly two, from the process of collecting wild yeast.



The original bottles had lost their "yeast" smell, with the exception of the apple which had a very strong yeast smell. I assume the bacteria and fungus had taken over the other three bottles.

The orange, apple and raisin had visible rising within a few hours. Raisin more than doubled in about six hours and overflowed its bottle so I used half to start a batch of bread.


Based on the test, this process is both simpler and more predictable than trying to capture a wild strain of yeast by setting your culture out on the windowsill or under a tree. Any fruit should work--if dried fruit several years old provided an immediate result, fresh fruit would probably be better. It also isn't necessary to have a full jar of mashed fruit--less than a tablespoon of each kind resulted in usable yeast growth within a few days.

Post on baking with this yeast

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