To cultivate natural yeast, you must tell yourself repeatedly: the yeast is alive and alive. It has its own personality and characteristics, not only to follow the book, but also to learn to control the variables outside the formula, which is also the charm of natural yeast. In The village baker, the author quotes a French baker, Parmentier, more than 200 years ago: No village baker can tell you the exact time of fermentation. Because of the weather, the humidity and temperature of the dough, the freshness of the flour, and the way the yeast is stored are variables that affect the rate of fermentation of the yeast. But the fundamental factors that determine the rate of fermentation of the yeast are temperature and acidity. [Acetic acid, lactic acid] The sour taste of natural yeast bread comes from acetic acid and from lactic acid. Acetic acid is like vinegar, and lactic acid is like the taste of milk. The sourness of most breads is always more inclined to one side in two sour balances. The very famous San Francisco natural yeast bread is known for its acetic acid. Bread made from solid yeast and low-fermented yeast will have an acetic acid taste. Bread made from liquid yeast and fermented yeast with high temperature will show a lactic acid taste. [Sour balance] In "Flour water salt yeast", Ken Forkish shows that the natural yeast bread he pursues has a balanced taste. The sour taste is between acetic acid and lactic acid, and it matches anything and wine in three meals a day. All right. Therefore, the ratio of fermented gouache in his book is 80%, that is, in weight, water is 80, and powder is 100. Because he found that the mash of the yeast is closer to the main dough than the gouache, he can achieve the balance he pursues. The bread made in this way can taste the aroma of wheat and fermentation. After eating, the mouth is full of fragrance, and the two sour tastes are balanced. No one has overshadowed the other. [Materials for making fermented materials] The yeast used in the recipes in the book is made of high-powder mixed whole wheat flour. This collocation is to present the flour flavor of some hand-milled mills in France. The addition of a small amount of whole wheat will make the bread darker and rougher, more like the bread he saw while studying in France. [variables affecting natural yeasts] 1. Fermentation water content. The yeast with high water content is fermented quickly, and the bread taste is lactic acid; the yeast with low water content is fermented slowly, and the bread taste is acetic acid. 2, temperature. 78F-90F (26C-32C, more lactic acid produced by yeast; 55F-65F (13C-18C), more acetic acid produced by yeast. 3, flour. Whole wheat, rye is faster than white flour, feeding time It is different from the number of times. It is best to use natural wheat from the beginning to mix whole wheat or rye or a mixture of the two. 4, salt. Salt has the effect of slowing down the fermentation. 5, dry yeast powder. Dry yeast powder will use the fermentation of the main dough. In the middle, Ken's bottom line is not in the fermentation of the yeast. All the above information and the following methods of feeding the yeast are all from Ken Forkish. The temperature of raising yeast from the beginning is the key. If the room temperature is low in winter, try to raise it in the summer. According to his method. Under normal circumstances, after 12 hours, the yeast will grow to 3-4 times, and the cover image will fall back to 2 times after 24 hours. The original amount is large, the amount below is I write in 1/5 volume. All the last day of feeding has a number of 42.5 grams, please round it up.
Day 1. At any time between morning and noon, the container was mixed with 100 grams of whole wheat flour and 100 grams of water (temperature 90F/32C). Stir well by hand and leave no dry powder. Leave the lid on the air for 1-2 hours without covering the lid. Then cover the plastic wrap or lid and let stand at room temperature 75F-90F (24C-32C).
Day 2 At any time between morning and noon, take 50 grams of the first day of the yeast, mix 100 grams of whole wheat flour and 100 grams of water (temperature 90F / 32C). Stir well by hand and leave no dry powder. Leave the lid on the air for 1-2 hours without covering the lid. Then cover the plastic wrap or lid and let stand at room temperature 75F-90F (24C-32C).
On the second night of the night, you should be able to see small bubbles in the yeast, and it will expand slightly.
Day 3. The yeast should grow up to 2 times larger, with bubbles and alcohol. At any time between morning and noon, take 50 grams of yeast, mix 100 grams of whole wheat flour and 100 grams of water (temperature 90F/32C). Stir well by hand and leave no dry powder. Leave the lid on the air for 1-2 hours without covering the lid. Then cover the plastic wrap or lid and let stand at room temperature 75F-90F (24C-32C).
On the third night, smelling the yeast, there will be a more exciting taste, like a sour porridge.
Day 4 At this time, the yeast should be twice as large. In any time between morning and noon, take a little less ferment (40 grams) than before, mix 100 grams of whole wheat flour and 100 grams of water (temperature 90F/32C). Stir well by hand and leave no dry powder. Cover with plastic wrap or lid and let stand at room temperature 75F-90F (24C-32C).
On the fifth day, the yeast was already very active and could be used to make bread. In the morning between 7-9 am, take 42.5 grams of yeast, mix 80 grams of high powder, 20 grams of whole wheat flour and 80 grams of water (temperature 90F / 32C). Stir well by hand and leave no dry powder. Cover with plastic wrap or lid and let stand at room temperature 75F-90F (24C-32C).
After 6-8 hours, that afternoon, the yeast can be used to make bread.
Conventional feeding methods. The feeding ratio is as follows: 50 g natural yeast 50 g whole wheat flour 200 g high powder 200 water (85F-90F/29C-32C)
Prepare the feeding method before baking. A (in the morning two days before baking bread): Take the refrigerated yeast and take 100 grams of the yeast (remained thrown or self-handling) and put it in a bowl, cover the plastic wrap, and warm it at room temperature 30- 60 minutes. Then mix 50 grams of whole wheat flour, 200 grams of high flour, 200 grams of water (temperature 95F / 35C). Mix well by hand and leave no dry powder. Cover the plastic wrap and find a warmer place at room temperature overnight. B (that is, the next day, the morning before the toast): Feed the yeast once more in the regular feeding ratio. Take 50 grams of the yeast in step A above (that is, just fed the previous day), mix 50 grams of whole wheat flour, 200 grams of high flour, 200 grams of water (temperature 85F-90F/29C-32C). Mix well by hand and leave no dry powder. Cover the plastic wrap and find a warm place for 6-8 hours at room temperature.
Method of preservation of yeast. After 6-8 hours, the yeast can be used to make bread. Take out the amount of yeast needed to make the bread. The remaining yeast does not need to be fed and is stored directly in cold storage. Specifically, use a sealed fresh-keeping bag to dip some water into the bag. If it is small, do not allow more water to flow out, put the yeast into it, seal it, and store it for 7-10 days. The author says it can be kept for up to 1 month.
Examples of feeding time. For example, toasted bread on Sunday morning, the frozen yeast should be taken out two days in advance. 1. At 8 am on Friday, feed the chilled yeast in the first step of step 10. 2. At 8 am on Saturday, follow the second step in step 10. 3. On Saturday afternoon, after 6-8 hours, you can use the yeast in the main dough.
1, try to use vertical and vertical containers, so that you can easily observe the expansion. 2, pay attention to the amount of feeding on the fourth day and the time to cover the plastic wrap is not the same as the first three days. 3, the active and mature sign of the yeast is that after 7-8 hours of feeding on the fifth day, there is a medium-strength stimulating sour taste, pulling the yeast with water-soaked water, you can see the same structure inside the spider web. 4. On the fifth day, the yeast is fed as usual. The newly-produced yeast is still unstable and continues to be fed for two or three days at room temperature. If the yeast can grow regularly and fall back, it means that it can be used as bread. 5, note that step 9 is the regular feeding ratio, that is, just to maintain the vigor of the yeast, not intended to be used for bread. Step 10 is to feed the bread before the feeding, that is, the fed yeast is added to the main dough. It should be noted that the amount of the yeast removed in the first step of step 10 and in step 9 is different and the difference is doubled. 6, seasonal adjustment of feeding yeast in winter. Method one, when the yeast is mixed into the main dough, add about 25 grams or more of the yeast to the original side to promote fermentation. Method 2: When the yeast feed is activated in the morning, add 15-25 grams of the amount of the yeast, and the amount of other water powder does not change. 7, seasonal adjustment of feeding yeast in summer. If the bread made in the summer is too acidic, the amount of the yeast will be appropriately reduced when the yeast is fed in the morning, and the amount of other water powder will not change. (The specific amount of the author did not write, it is recommended to try from 10 grams, take notes, see the results, and then adjust) Tips 6 and 7 on the adjustment is for pure natural yeast bread, that is, when doing the main dough There is no bread added with dry yeast powder. Because dry yeast powder is highly active, it will not be affected as much by the seasons even in winter. 8, it is recommended to familiarize yourself with the sour taste of your yeast and find the flavor you like. a. If the yeast is too acidic, use the cold water in the morning, or make some of the main dough in advance, so that the yeast has not been sour. For example, if the room temperature is above 80F/27C, the main dough can be made 1-2 hours in advance. b. Conversely, if the room temperature is lower than 65F-70F (18C-21C), ensure that the water temperature is 95F/35C when feeding the yeast in the morning. After mixing the yeast and the new gouache, the dough temperature reached 78F-80F (26C-27C). 9. The old yeast that is left in the feed is usually thrown away. If you feel pity, you can also refrigerate it. Do some foods that are difficult for the organization and do not require the organization, such as pancakes, dough, taro, quick cake, biscuits, muffin, etc., and there are still many uses. There is a classification on my homepage about the way to re-use the remaining yeast: https://www.xiachufang.com/recipe_list/102084285/ I also have a lazy way to heat up the unused old yeast microwave oven. Feed the chicken. 10, if you already have natural yeast in your hand, and you want to try Ken's yeast, you can follow the regular feeding method in step 9, and you can transfer it almost three times. 11. Do not use bleached flour to feed the yeast. Because of over-processing, the nutrients needed for the yeast are removed. 12, too high-gluten flour is not suitable for the cultivation of yeast, because the protein content will increase, the starch content inside will be reduced. The microbes in the yeast are mainly based on starch to provide nutrition. 13, using rye instead of whole wheat, the yeast will grow faster, because rye is more nutritious. 14, a common situation is that the first two days of the growth of the yeast will not grow until the third day or the separation of gouache. Don't be discouraged at this time, as long as the batter has no long hair on the surface, you can continue feeding even if you don't grow taller (even if the powder is separated). This is because the growth of the first two days is another kind of bacteria, it will also release gas when growing, so that the batter grows. But its life cycle is not long, it will die soon, then just wait for the real yeast to produce. As long as the environment is sour and the temperature is high enough, yeast can be produced. Adding half a vitamin C or lemon juice is a way to help the environment get sour. 15, talk about my personal experience. It was November 2013, and I started to grow the yeast in the big winter. After the second day of the first round rose 2 times, the fourth day did not move, the fifth day long hair, the failure ended. After the second day of the second round rose 2 times, the fourth day did not move, the fifth day dead horse as a living horse doctor, added lemon juice, fruit vinegar did not change. On the seventh day, take 70 grams of yeast + 70 grams of rye + 30 grams of high powder + 50 grams of warm water, and finally rose 2 times. On the eighth day, it was also doubled in the same way, and then officially converted into a ferment by using Ken's conventional feeding method. 16, often have a kitchen friend asked me "now want to feed" and so on the issue of feeding. Imagine that yeast is a living little animal. The sugar in the flour is their rice. They keep their lives by eating the sugar in the flour. The gas that causes the batter to swell is the excrement that they eat and discharge. When the batter volume begins to increase, it indicates that the yeast is constantly eating, excreting, and reproducing more yeast. When the batter expands 2-3 times and is no longer long, it means that the sugar in the flour has almost been eaten. Now the yeast in the batter has the most yeast and the yeast is the most active. The grain is gone. If you don't add new powder, the yeast will go hungry and slowly start to fall back. Because there was no excretion without eating, no gas was produced. At this time, it is time to "eat" the yeast, that is, to feed the new powder. When the fertility falls back to the height of the initial unexpanded, it is basically hungry. 17, the best way to maintain the vitality of the yeast is to try to feed regularly at the same time and at the same time. a. If you often make bread: Feed the next day. That is to feed once in the morning, put it at room temperature for 12 hours, put it in the refrigerator at night, and repeat this step the next morning. b. Bread on weekends: Take it out of the fridge on Friday morning, feed it on Friday night, and make a yeast on Saturday morning. How to feed without death regulations, all depends on their own schedule. After being skilled, it doesn’t take much time to feed the yeast.