Chapter 9

Mashing

Factors Affecting Mashing Conditions

Temperature

As mentioned, the temperature influences the amount of extract produced (yield) and the fermentability of the wort during mashing. In general, the higher the temperature, the greater the yield but the lower the fermentability of the wort.

Time

Mash times are another factor influencing yield and the fermentability of the wort. In general, longer mash times increase the concentration of the extract, but the rate of increase becomes slower (19). In general, short mash times at high mash temperatures will produce more dextrinous worts, while longer mash times at high temperatures produce more fermentable worts.

Mash pH

For most beers, the optimum pH range for mashing is from 5.1 to 5.6, although values toward the lower end (5.1-5.3) are usually considered optimum (19). The "normal" mash pH, however, depends on the type of malts employed, the pH of the water, and the method of mashing.

Acidification of Mash

To lower the pH of the mash it can be corrected by the addition of acid malts, salts, or acids, or by biological acidification.

Malt Modification

The temperature used for mashing is a function of malt modification. This is because the extent of modification influences the rate of starch solution. Lower temperatures are needed for well-modified malts because most of the enzymes are destroyed in the kiln, particularly beta-amylase, which is necessary for starch conversion.

Mash Water

The nature of the mashing water has an important influence on mash reactions. The ions of major importance at mashing are those of calcium, carbonate, and bicarbonates (8).

Mash Thickness

Thin mashes (i.e., its ratio of grist to brewing water) favor the conversion of starch to sugars, while in thick mashes the rate of saccharification is retarded, probably because the accumulating sugars competitively inhibit the hydrolytic enzymes (11).

Click on the following topics for more information on mashing.