Mash-out
After the enzyme rests, the mash is raised to its mash-out temperature. This frees up about 2% more starch, and makes the mash less viscous, allowing the lauter to process faster. Although mash temperature and viscosity are roughly inversely proportional, the ability of brewers and distillers to use this relationship is constrained by the fact that α-Amylase quickly denatures above 78 °C (172.4 °F). Any starches extracted once the mash is brought above this temperature cannot be broken down, and will cause a starch haze in the finished product, or in larger quantities an unpleasantly harsh flavor can develop. Therefore, the mash-out temperature rarely exceeds 78 °C (172.4 °F).
If the lauter tun is a separate vessel from the mash tun, the mash is transferred to the lauter tun at this time. If the brewery has a combination mash-lauter tun, the agitator is stopped after mash-out temperature is reached and the mash has mixed enough to ensure a uniform temperature.
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