Lesson 2 - Mashing Biochemistry
This lesson deals with the biochemical aspects of mashing. We will meet the main substrates and the enzymes that break them down. We will learn what enzymes are, how they operate and how they are affected by the environment of the mash. Finally, we will cover how starch is gelatinised, liquefied and saccharified to make a wort with the desired sugar spectrum.
Mashing Substrates
The biochemical essence of mashing is to continue where malting left off and convert endosperm material into wort. This involves taking large molecules and making them smaller. These large molecules are our substrates.
A substrate is the word for the material on which an enzyme acts. The enzyme catalyses the conversion of the substrate(s) into the product(s) of the reaction.
The substrates we want to reduce in size include:
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starch
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non-starch carbohydrates
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proteins
And those we prefer to leave intact or breakdown to a lesser extent are:
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lipids
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polyphenols
Our key substrates are starch and protein.
Breaking down starch provides the fermentable material and a source of energy for our yeast while breaking down protein provides its nutrition.
Let us first consider starch.