Noob_Brewer
Well-Known Member
This is the typical fermentation drive I use for Conan based strains. I slightly underpitch and do a 1L starter or less based on mf date 18-24 hours prior to brew day. not specifically to boost the cell count but to insure the yeast is active at the pitch. I pitch at 68*f and let it free rise 70-72 for the first day or two. Once it starts it’s most active fermentation, usually the tailend of day two/day three, I drive it to 74-76*f depending on the specific yeast. 1318 I try not to go over 74/75. With imperial a24 It really produces esters at 76. I will hold it there until visual fermentation is over and then it slowly drop back to 70-72 and will hold it there for 48-72 hours after hitting fg to clean up any vdk or acetaldehyde.
We all know that stressing the yeast cause them to produce esters. Though I don’t have true scientific evidence why this specific drive works, my impression is that by repeatedly changing the temperature of the yeast’s environment, they must constantly adjust to the changes which causes them to be under constant stress
@Dgallo, just to be sure you under pitch this yeast correct? About .6? Reason why I ask is that my high krausen has past and its only been 25hrs. I’ve been pitching a24 at a 1.0pitch rate (OG 1.065-1.067) and typically the krausen is actually fallen by end of day three with very little bubbling activity so visually my fermentation’s seem to be done by day 4 maybe day 5 tops. I haven’t been pushing the temp drive like you. Been pitching and holding at 68, then bumping a degree each day until it gets to 71 on day 6 or 7. This batch, used same 1.0 pitch rate but decided to let active fermentation drive the temps up. I’m currently at 73 degrees and I pitched 25hrs ago. Tempted to just let it hold here until active fermentation is over just in case there is a temp differential inside the FV since my probe is on outside with styrofoam. Don’t want the fusels. Then will drop to 71 for yeast cleanup. Was just surprised to see this much of a temp rise this quickly. Thoughts? Just trying to determine if your peak fermentation activity around day 3ish is a little later because of pitch rate