. Factors such as temperature, PH and length of time of the mashing must be carefully controlled so as to create optimum conditions. Conversion temperature is typically 650C, but mashing may begin at lower temperatures (e.g. 45OC) if the malt is relatively tinder-modified.Some classes of proteins and starches are insoluble in water. During mashing, the proteins are broken down by an enzyme system. Proteases hvdrolyse the proteins to peptides and other less complex nitrogenous compounds, and peptidases subsequently break down the peptides to amino acids. The starch is broken down by the amylase enzyme system to glucose, maltose and dextrins.In case of poor malt quality, enzymes from the malt can be supplemented with exogenous enzymes.Adjunct MashAdjuncts such as rice and maize are not pre-germinated and do not contribute enzymes. Furthermore, their starch has a higher gelatinization temperature than malt starch. The adjunct is therefore mixed with water and cooked. The adjunct mash is then mixed with the malt mash and the malt enzymes break down the adjunct starch. Sugar and glucose syrup can also be used as adjuncts. Since no enzymatic breakdown is required, these adjuncts are added to the wort kettle. Wort SeparationDuring mashing, the substances in the malt and adjuncts are broken down and dissolved in the brewing water. In addition to sugar and protein compounds of various complexities, the mash also contains insoluble material (spent grains). The wort is separated from the spent grains by straining through a porous filter bed formed by the husks. The residual extract in the filter bed is leached out with sparging water.The temperature of the wort during straining is about 75-780C.Wort BoilingFollowing removal of the spent grains, the wort is heated to boiling in the work kettle and addition of the hops takes place.During wort boiling:I.All enzymes are inactivated to prevent the continued breakdown of proteins during fermentation.2.T...
