Yeast -Types and Roles in Bakery Industry

Bakery Industry uses Yeast in various types for bread and biscuit production .Yeast acts as leavening agent and it gives puffy structure to bread and Cracker biscuits .Yeast is an unicellular living organism .Its growth is max at higher humidity and temperature 45 deg c .Yeast action on food releases carbon dioxide which gets entrapped in dough and gives puffiness to the product after baking .Yeast are used for sour dough products or Sponge dough products . Sponge are prepared in cracker production yeast is added during mixing are then kept for 18-20 hrs before production.

Commercial yeast are of two types - Compressed yeast and Dry yeast


Compressed yeast - These can be further calssified as

• Breweries yeast - It acts on malt to give alcohol and carbon dioxide.
• Distillers yeast- It acts on molasses to give alcohol and carbon dioxide .
• Bakers yeast - It acts on sugar to produce carbon dioxide and alcohol. Carbon dioxide is the main by product.

Other features of compressed yeast

• Its available in cake form
• Its cheaper than dry yeast
• Moisture content is 80%
• Life of compressed yeast is 5 days
• Cell usage is 90-95%

Dry Yeast

• Its costlier than Compressed yeast
• Its is available in powder form
• Moisture is around 5%
• Life of dry yeast is more than one year
• Cell usage around 60%