Wort Separation(book excerpts)
After mashing, when the starch has been broken down, the next step is mash separation, i.e., lautering—separating the liquid extract (the sweet wort) from the residual undissolved solid materials found in the mash. Sparging is the process of trickling water through the grain bed to extract sugars. The method of separating the wort from the mash solids and the equipment used is mainly a matter of choice on the part of the individual brewer, and sometimes of tradition. Wort separation, i.e., lautering may be carried out by any of a number of different methods: (1) the mash tun, (2) mash/lauter tun, (3) the lauter tun, or (4) the mash filter. The lauter tun is internationally accepted and continues to be the predominant wort separation device. Wort separation is important because the solids contain large amounts of protein, poorly modified starch, fatty material, silicates, and polyphenols (tannins). The objectives of wort separation (i.e., lautering) are: (1) obtain good extract recovery with low settable solids, low colloidal fine particles, and low oxygen pickup; (2) spent grains with minimum moisture; and (3) operate within the acceptable cycle time.
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