The mother dough, commonly called natural yeast or pre ferment, is a mixture of flour and water that has been left to ferment with added sugar for a certain period: this process allows micro-organisms present in the flour, in the water and in the air to reproduce and ferment.
These microorganisms present in the mixture, are saccharomyces (among which the various strains of Candida Saccharomyces e) and heterofermentative lactic bacteria (parts of the Lactobacillus families such as brevis, casei, acidophilus, plantarum, etc.). The bacteria and the yeasts of the atmosphere transforms the sugars of the compound into acids as well.
Moreover, unlike the brewer's yeast (consisting simply of a single bacterium, part of the Saccharomyces strain), the mother yeast contains many other types of bacteria, part of the genus Lactobacillus, and responsible for the process of transformation of sugars into lactic acid.
What is the difference between the two?
The mother yeast, due to its composition, can be subject to two types of fermentation; alcoholic or lactic, giving the bread or pizza a particular taste and making it more digestible.
This natural yeast has an ancient history behind it. It is thought that the fermentation, which we have been using daily, was discovered in 2000 B.C, by coincidence. There is a hypothesis that this great discovery was made in Egypt, when a piece of unleavened dough was left under the sun, starting to grow and grow, increasing in volume. Once cooked, the bread was much softer and more pleasant than usual unleavened bread.
However, the mother dough is not found on the market. You have to make it yourself, and it is precisely for this reason that there are several philosophies on which is the best way to prepare it, and consequently, many recipes.
All the recipes to make mother dough start from a base of water and flour. These recipes can then be enriched with sugar, honey, yogurt or even an apple slice.
These are the ingredients you need to prepare mother yeast:
- Flour: The best flour for the preparation of natural yeast is a high yield flour with a good gluten percentage.
- Water: Drinking water, not too rich in mineral salts, since these could get in the way of the fermentation process of the mother dough. You can also try with carbonated water! Carbon dioxide is in fact an essential element in the transformation of sourdough.
Additional ingredients: It is not necessary, but to speed up the work of microorganisms during the preparation of a natural yeast, you can add fruit, peels or even yogurt to soften it. These ingredients also accelerate fermentation.
Refreshments are necessary for the preparation of natural yeast.
Refreshments are fundamental and necessary steps for the preservation of your yeast, keeping it alive and healthy for as long as possible. They usually precede the preparation of the final dough, with the aim of enhancing the fermentative capacity of your yeast, as well as lowering the degree of acidity.
Remember that yeast behaves exactly like a living organism, and it is therefore necessary to nourish it at least once a week, precisely through refreshments.
As a rule, the innermost part of the yeast is removed, one part is extracted, then flour and water are added, however,there are distinctions.
For the refreshments, designed to keep the yeast alive, 50% of water is used along with the added flour, while for the yeasts in preparation for the dough the same weight of flour is added with an addition of 10%, and 50% of water on the weight of the yeast.
For every 1 kg of yeast: + 1100 g flour + 500 g of water.
The fermentation phase ends when the yeast has tripled its volume. Refreshments are usually repeated three times before the end of the leavening process.
A fundamental advice is to check the volume reached by your yeast using a "spy", a small part of yeast, inserted into a graduated cylindrical glass to guide and help follow leavening.
As for the preservation of your yeast, place your sourdough in a glass container in the fridge. If refreshed at least once a week and stored in a fridge at about 4°C, it can survive for about a week. To keep the product longer, it is necessary to pulverize it.
Ingredients: 100 g of ripe fruit - 200 g of flour - 50 g of water
Start by kneading the ingredients homogeneously, then place your dough in a container full of water, at a temperature of 20°C to 24°C. The amount of water must be at least four times higher than the weight of the pasta, which must in fact sink completely. Let it rise for 48 hours at a temperature of 26°C / 28°C.
After 48, thanks to the carbon dioxide, the mixture will start to float. If this does not happen, try repeating the operation, kneading with the same weight of flour and 40% of water.
When your yeast has finally reached maturity, you can move on to the next step, and proceed with refreshments.
Ingredients: 200 g of flour – 90 g of water - 1 tablespoon of oil - 1 tablespoon of honey
Start by kneading all the ingredients, creating a dough, then put the mixture in a glass container (with lid). This should be left to stand at a temperature of 25°C for 48 hours.
Then take 100 g of the dough, add 100 g of flour and 45 g of water, making sure at all times that the temperature is right.
Mix well, then close the container and let your work rest for another 48 hours.
Freshen the yeast again in the same way, and repeat this operation for at least one / two weeks, repeating the refresh process every day, this should make it capable of doubling its volume in less than four hours.
Ingredients: 200 g of flour – 100 g of pureed fruit – 100 g of water
The use of mineral water is recommended.
Mix the ingredients homogeneously, and place them in a container filled with water at a temperature of about 20°C. The water must be four times higher than the weight of your pasta and cover it completely. Put the dough to rise at a temperature of 26°C / 28°C for about 48 hours, making sure is covered.
The dough will start to float, if developed optimally.
Then mix with an equal weight of yeast and flour, let it restuntil the yeast has reached maturity (usually takes 20/25 days).
How pre-ferment looks like after preparation
The yeast, following the preparation, can present itself in different ways.
If Mature, it will have an almost acid taste and an alcoholic scent, it will be characterized by a soft white paste and elongated alveolation, with a pH of 4-4.10.
Past leavening will have sour and bitter taste, acrid scent. The appearance will be greyish, with round alveolation and a ph of 3-3.8.
When is too weak, it will have a sour and sweetish taste, it will be white and poorly honeycombed. The pH will be around 5-5.5, and will smell like flour.
The sour yeast has a very strong taste, similar to cheese, mainly due to the butyric acid, a grayish color and the dough will be moist and sticky. The ph will definitely be too low.
The following are the best methods to solve these different problems
Yeast too strong
Cut your yeast into slices, soak it at a temperature of 20-22°C, with about 2 g of sugar for every liter of water. Then leave the slices to soak for 10-15 minutes, and squeeze the yeast and start the refreshments.
Here are the dosages:
- 200 g of yeast
- 400 g of flour
- 200 g of water
Once the refreshments are done, the yeast must mature in 4 hours at 28°C.
Yeast too weak
Start by refreshing the yeast by following these dosages:
- 250 g of mother yeast
- 200 g of flour type "00"
- 100 g of water
Start to knead, until obtaining a homogeneous and dry mass and let it rise as you usually would. You can then start the refreshments, dosing the flour with attention to the consistency of your yeast, so that it can ferment in 4 hours.
The washing procedure is the same as the previous one, but it will be necessary to rebuild the yeast.
- 250 g of mother yeast
- 500 g of flour type "00"
- 250 g water
- 20 g of egg yolk
- 3 gr of sugar
Knead until the work is homogeneous and dry, and let it riseup to three times its original volume.
At this point, start refreshing, dosing the flour and water in order to obtain a yeast with the right strength, able to ferment in 4 hours. Note that egg yolks and sugar will not be needed in subsequent refreshments.
The day before using your yeast you will have to freshen it up, and wait for it to activate for some time before using it.
At this point, you just have to choose a recipe and start experimenting.