Ask Mr. Wizard

Diacetyl Rests

TroubleShooting

Seth Adams - Annapolis, Maryland asks,
Q

I’ve seen the importance of diacetyl rests mentioned dozens of times. the description always states to increase fermentation temperatures to the 65–68 °F (18–20 °C) range for 24–48 hours or so. However, there is never a discussion of how quickly to raise the temperature. If I have a lager at 50 °F(10 °C), do I raise the temperature only 2–3 degrees per day until I hit the range (adding ~7 days) to avoid shocking the yeast or do I raise it much faster to no ill-effect?

A

Perform a diacetyl rest, build a simple aeration device, and convert recipes to larger batch sizes.

Response by Ashton Lewis.