Factors Affecting Starch Breakdown

The saccharification process in the brewing process determines the composition of fermentable extractables in the wort, while the various sugars and dextrins in the wort affect the fermentation process and beer quality. Therefore, brewers must master various factors that affect starch decomposition during saccharification in order to brew high-quality beer.

Malt variety and quality

The enzyme content of light-colored malt is usually higher than that of dark-colored malt, and the obtained wort contains more sugar and less dextrin. The higher the fermentation rate, the lower the degree of fermentation. Well-dissolved malt not only has high enzyme content, but also the endosperm cell wall is decomposed more completely, and the content is easily affected by enzymes. Therefore, with this malt, starch decomposition is fast and complete, and the wort produced has more foam, clear and transparent. ; Poorly dissolved malt, the opposite is true.

• Degree of crushing

If the malt has a lot of coarse grains after being pulverized, the raw material is not easy to absorb water, and at the same time, the relative surface area is small, which is not conducive to the action of enzymes, and the decomposition is incomplete, which affects the yield of raw materials; Affects wort filtration.

• Mashing temperature

Temperature has a great influence on saccharification, so saccharification should be stopped at the optimum temperature for various amylases. During the saccharification process, α-amylase will decompose long chain starch into low molecular weight dextrin. Time saccharification will produce more dextrin, so as to brew beer with low final fermentation degree and rich dextrin; β-amylase decomposes from the end of starch chain to form maltose, maltotriose and glucose, and its optimal temperature At 60°C~65°C, the deactivation temperature is 70°C. If saccharification is carried out for a long time in its optimum temperature stage, a large amount of maltose can be formed, thereby brewing a beer with a higher final fermentation degree.

• Saccharification time

During the saccharification process, the action of the enzyme is not uniform, and the activity of the enzyme can be divided into two time stages:

A. After 10~20min, the maximum activity of the enzyme is reached. The activity of the enzyme is maximum at the temperature between 62°C ~ 68°C.

B. After 40~60min, the activity of the enzyme decreased rapidly, and then decreased slowly.

With the extension of the saccharification time, on the one hand, the concentration of the extract solution will continue to increase, but the increasing process will become slower and slower; on the other hand, the maltose content will also continue to increase (especially when saccharified at 62 ° C ~ 65 ° C) , that is, the final fermentation degree of beer is also increasing.

• The pH of the mash

pH value is one of the decisive factors for the action of enzymes. We know that the optimum pH value of a-amylase is 5.6~5.8; the optimum pH value of β-amylase is 5.4~5.5. When the pH value of the mash is between 5.5 and 5.6, it can be regarded as the optimum pH value range of the two amylases. At this pH value, the extract concentration can be increased, more fermentable sugars can be formed, and the final fermentation degree can be improved.

• Mash concentration

When the concentration is low, more extracts can be dissolved; when the concentration is high, the activity of the enzyme can be better maintained, and the content of fermentable sugars and the final degree of fermentation can be improved. But compared with other factors, mash concentration had less effect on starch breakdown.