BLOOMING YEAST: History, Definition and Fermentation

  

         

Yeast comes from the Old English word “gyst”, “gyst” and from the Indo European word means boil, bubble, or foam. Yeast belong to the family of fungus, a eukaryotic single cell microorganism originated hundred years ago and at least 1500 species has been recognized.  The yeast species “Saccharomyces cerevisiae” convert carbohydrates into carbon dioxide and alcohol into fermentation. The product of this reaction has been use in baking and production of alcoholic beverage for thousand years ago. Yeast microbes are probably one of the earliest domestic microorganism. Archeologist digging Egyptian ruins found early grinding stones and baking chambers for yeast raised breads as well as drawing of 4000year old bakeries and breweries. In 1680 Dutch naturalist Anton Van        Leeuwenhoek first microscopically observed yeast, but time did not consider them to be living microorganism, but rather globular structure as researchers were doubtful whether it is fungus or algae. Theodor recognized them as fungi in 1837.

In 1857, a French Microbiologist  Louis Pasteur showed that by bubbling oxygen into the yeast broth, cell growth could be increased, but fermentation was inhibited. Pasteur prove that alcoholic fermentation was conducted by living microorganism and not by chemical catalyst. ( source Wikipedia)

Blooming the Yeast

Blooming is use to test yeast,  especially if the yeast has been stored for a long time. Basically yeast is alive when stored, it gradually die. Testing the yeast ensures there are live yeast cell to make bread. This is also known as proofing yeast.  Blooming is not necessary if you are using fresh yeast.

What you need?

1/2 cup Water

2 Tablespoon sugar

1 Tablespoon Yeast

Measuring cup

Procedure

In a measuring cup combine water, sugar and yeast. Let it sit and wait for 15-20 minutes until it bloom. The yeast is active and healthy if the foam is risen to one mark of cup. If not it means your yeast is dead and need to buy new one.  You must store your yeast in an airtight container.

What happen during fermentation?

Fermentation is a process of breaking down particular substance by bacteria microorganism or in the case the Yeast. The yeast in measuring cup is active by adding water and sugar. The foaming result of Carbon Dioxide released by yeast eating sucrose on sugar. Typically fermentation release heat or gas as by product . Yeast microbes react differently  in varying environment. If the water is too hot it will die it will kill the microorganism. The yeast alone does not react until sugar  and warm water is added.