Ask Mr. Wizard

Mash Stirring


Benjamin Stange - Springfield, Missouri asks,

I am working on an all-electric HERMS system for my homebrew setup. One of the components I have read about on some setups involves utilizing a mash stirring motor. I’ve seen some guys pull them out of bread machines or ice cream makers (high torque, low RPMs). Do you think there is any benefit to this? I was considering doing this and then stirring down to a certain level, but leaving the bottom 4-6 inches unstirred so as not to disturb the filter bed. Some brewers I’ve seen stir for the duration of mash, and then stop the stirrer for a final recirculation period before draining, but I would think this would promote channeling along the stirring mechanism. One more consideration: Do you think there is considerable risk of hot side aeration using a stirring mechanism during the mash, and should a homebrewer be concerned about this?

This is a pretty weighty topic because stirring the mash does a few things to the mash. To avoid a geeky treatise I will cover this from a treetop level. So why
Response by Ashton Lewis.