I learned one thing recently, which there are no good or bad bacterias on the earth. Poisonous or nonpoisonous substances are created by these bacterias in the circumstance of the quality of ingredients that we use and atmospheres where we make such as temperature, weather, humidity and so on.
To build strong and stable yeast,
- You must keep a starter at 82F /28℃ for the first stage. Fermentation occurs vigorously in the warm environment. At over 86F/30℃, Other bacterias will be also active to disturb growing the yeast. When Saccharomyces cerevisiae ( yeast )grows in a starter, the yeast keeps out of the other bacterias. Alcohol fermentation keeps out of the other bacterias,too.
- For sourdough: Lactobacillus sanfranciscensis exists as good yeast. You can check these out: Ironically I keep making sourdough with flour and water Test1 and 2, even though I want to make the natural yeast ( Old dough )with flour and water for non sour bread. As soon as your starter has strong acetic or unpleasant flavors, you won’t be able to fix the flavors.
- For yeast water: how I made raisin yeast water . I recommend to make raisin yeast water for a first try because raisin yeast water is very strong and easy to take care of. It also makes soft and fluff crumb, and has no strong flavors. If you want to try fresh fruit yeast water, you can add 1 tsp raisin yeast water into a jar with fresh fruits and water and ferment it 24 hours at 82F.