This is my report for October's challenge.
This month, with moving and everything that goes along with that, I didn’t get started with my experiments until there was less than 2 weeks left in the month. So needless to say, I didn’t get as much done as I hoped. I had hoped to try to capture wild yeast in 3 different ways, and learn to stretch commercial yeast in at least 3 ways.
I started with a technique called Japanese Yeast Water. You put a handful or two of raisins in a jar filled 80% with water. Store it on the counter or in a cupboard. You loosely cap it and in a couple of days, the raisins will begin to float to the top. In 3-6 days, you should be seeing bubbles on the top of the water. The bubbles are the yeast. It was at this stage, both times I tried it, that mold grew on the raisins floating on the top. I don’t think this kind of yeast is as useful as some others so since I lost the yeast water twice, I gave up on it. If you are interested in learning more about it and how to use it, visit http://originalyeast.blogspot.com/2008/02/how-to-make-yeast-water.html.
Next, I started what I call a wild grape yeast sponge. Aside from floating in the air, yeast is also present on the skin of fruits, especially grapes and berries. So if you mix together equal parts of flour and water then add some grapes to the mixture, you should get yeast. I did that and set it in a warm place, loosely capped. I think on the second day, there were small bubbles in the mixture and it smelled slightly yeasty. The third day, there were more bubbles but the smell turned to something off. The next day, the bubbles were gone and the smell was almost enough to make me throw up. So I got rid of the grapes and kept it for one more day. No progress so I threw it out. I tried this one again as well. On the second day, there were bubbles and the yeast smell was there so I got rid of the grapes before they had a chance to go bad and ruin another batch. I fed it an equal part of flour and water and let it sit. The next day there were still bubbles so I fed it again. The next morning, the bubbles had disappeared and that nasty smell was back. Failure again so I gave up on that method as well.
The third way to capture yeast I wanted to try was making a sourdough starter. There are lots of recipes online to start a starter with commercial yeast but that wasn’t the point of my experiment so I found a recipe for a starter that I think has gotten me my first success!
Procedure for Making Sourdough Starter
Day 1: mix...2 T. whole grain flour (rye and/or wheat)2 T. unsweetened pineapple juice or orange juiceCover and let sit at room temperature for 24 hours.
Day 2: add...2 T. whole grain flour2 T. juiceStir well, cover and let sit at room temperature 24 hours. At day 2 you may (or may not) start to see some small bubbles.
Day 3: add...2 T. whole grain flour2 T. juiceStir well, cover and let sit at room temperature 24 hours.
Day 4:Stir down, measure out 1/4 cup and discard the rest.To the 1/4 cup add...1/4 cup flour*1/4 cup filtered or spring water
*You can feed the starter whatever type of flour you want at this point (unbleached white, whole wheat, rye). If you are new to sourdough, a white starter is probably the best choice. All-purpose flour is fine--a high protein flour is not necessary.
Repeat Day 4:Once daily until the mixture starts to expand and smell yeasty. It is not unusual for the mixture to get very bubbly around Day 3 or 4 and then go completely flat and appear dead. If the mixture does not start to grow again by Day 6, add 1/4 tsp. apple cider vinegar with the daily feeding. This will lower the pH level a bit more and it should wake up the yeast.
The yeast we are trying to cultivate will only become active when the environment is right. When you mix flour and water together, you end up with a mixture that is close to neutral in pH, and our yeasties need it a bit more on the acid side. This is why we are using the acidic fruit juice. There are other microbes in the flour that prefer a more neutral pH, and so they are the first to wake up and grow. Some will produce acids as by-products. That helps to lower the pH to the point that they can no longer grow, until the environment is just right for wild yeast to activate. The length of time it takes for this to happen varies.
When using just flour and water, many will grow a gas-producing bacteria that slows down the process. It can raise the starter to three times its volume in a relatively short time. Don't worry--it is harmless. It is a bacteria sometimes used in other food fermentations like cheeses, and it is in the environment, including wheat fields and flours. It does not grow at a low pH, and the fruit juices keep the pH low enough to by-pass it. Things will still progress, but this is the point at which people get frustrated and quit, because the gassy bacteria stop growing. It will appear that the "yeast" died on you, when in fact, you haven't begun to grow yeast yet. When the pH drops below 3.5--4 or so, the yeast will activate, begin to grow, and the starter will expand again. You just need to keep it fed and cared for until then.
Once your wild yeast is growing, the character and flavor will improve if you continue to give it daily feedings and keep it at room temperature for a couple of weeks longer.After that time, it should be kept in the refrigerator between uses/feedings.
I followed the direction as closely as possible. I did forget about it one night and fed it the next day but everything is still alive and going well. Around the time she stated, the starter appeared dead so I used the vinegar like she said and the next day, is was bubbling again.
I will continue on with keeping the sourdough starter alive and actually making something with it. I will also work on doing some of the yeast stretching things I’ve read about and report back another month on those things.