When brewing craft beer, why should the sparging water be controlled at 78 degrees Celsius

When craft beer is brewed, some processes require our attention to some details, such as washing up. The temperature of the sparging water should be controlled at 78°C. Do you know why it should be controlled at this temperature?

Sparging water is not the more the better

The more water in the bath, the more extracts will be washed out from the grains, and the yield of extracts will naturally be higher.

However, the more sparging water is used, the more water will be evaporated when boiling. So we have to find a compromise among the following factors

(1) Filtration time and extract yield;

(2) Wort boiling time and energy costs.

The higher the concentration of the first wort, the less its amount, and the more water must be used for washing; and the higher the concentration of the first wort, the higher the yield of the extract. For this, the filtration temperature has played a very important role.

The higher the filtration temperature, the lower the wort viscosity

This means that the filtration speed is the fastest at 100°C, but we also need to consider that undissolved starch will dissolve from the grains during washing (saccharification continues), and only when the temperature does not exceed 78°C can α-amylase continue Post-saccharification is performed, so filtration at 100°C results in so-called "blue saccharification".

Since the water temperature of 80°C will destroy α-amylase, the temperature of wort filtration should be kept below 80°C.

Residual water

The washing of the grains should be carried out until the concentration of the full wort is reached, and the low-concentration wort filtered out at the end is called "the residual water of the washing grains". Sometimes the residual water after washing can be used as the saccharification water for the next feeding.

However, if you are making "high-concentration craft beer", you should not wash the lees too strongly, otherwise the wort concentration will drop too much.

Therefore, a certain limit should be mastered in the washing of grains: excessive washing of grains will wash out polyphenols, bitter substances and silicic acid and other undesirable substances in the wheat husk, which will affect the quality of craft beer; excessive washing of grains will also reduce the concentration of wort, Increase energy consumption.

The concentration of residues after washing is generally controlled at 1.0-1.5P. If it is brewing high-grade craft beer, the concentration of residues should be higher.

The above are the things to pay attention to when the sparging spent grains. After understanding the reason, I believe everyone will brew according to the process requirements.