Baking calls for a few specific things for it to be successful: patience, practice and understanding how ingredients react to heat and each other. One such ingredient, which requires solid understanding for a successful baking experience, pops up every time for bread or a few pastry recipes. It is a make it or break it ingredient for the recipe and hence knowing how to use it is crucial. The ingredient I am talking about is yeast.
What is yeast exactly?
Saccharomyces cerevisiae or Baker’s yeast is the lifeline of good baking, quite literally. Member of the fungi family these are single-celled organisms that are incorporated in bread/pastry doughs and even batters as a leavening agent i.e. to make things fluffy.
What does yeast do?
In simple terms, the basic purpose of yeast is to incorporate air into a mixture. Without getting too deep into the biochemistry of it, the yeast eats the sugar/starch present in a mixture and produces carbon dioxide gas as a waste product. This process is called fermentation (just like the process of making alcohol). The Gas so produced gets trapped in the batter/dough like tiny air bubbles and hence makes the mixture rise and once baked the air expands because of the heat and we get lovely fluffy bread.
How to use yeast in a recipe?
Yeast is to be dissolved in lukewarm water before adding it to the mixture. Sugar is recommended to be also dissolved in this solution of yeast and water if you want the dough to rise in a short duration of time.
What kind of yeasts to be used?
There are multiple kinds of yeasts used commercially and domestically depending on their availability and their needs but a few common types are most prevalent and easy to procure. Knowing the type of yeast being used is important as the type of yeast being used decides the quantity of yeast that is to be added to the recipe. Active dry yeast is the most common type of yeast used domestically. Use 3 grams of yeast for every hundred grams of flour used along with 6 grams of sugar. This yeast has to be given some time to “bloom” where the yeast dissolves in the solution and gets activated. You can tell that the yeast has activated when a layer of foam appears on top. This takes about 15 minutes depending on the weather.
Yeast dos and don’ts
Do not subject yeast to temperatures higher than 60C, as high temperatures can kill the yeast. Too low of a temperature does not allow the yeast to grow either. An excessive amount of salt and sugar also hinder yeast growth.