Originally Posted by permo
WLP029 is clean all the way up to 70 degrees. I have brewed a great kolsh even letting it rise to 72. Just dont forget to cold condition(lager) your beer for as long as you can stand before bottling/kegging. IMO, this is where the kolsch magic happens.
Definitely true! It is an ale yeast that's designed to ferment from 65-69 degrees with a good lager time. Only concern with letting it ferment at 65-67 is that the active fermentation can raise the temp 5-10 degrees....
If the thermometer on the side of the fermenter is reading between 65 and 69, good to go. I'd certainly not dump it if it gets a bit warmer but it --may-- influence the flavor. I'd be most concerned about getting the correct temps for the first 3 days if you can.