I think I just made my first beer with diacetyl in it (well, first with un-broken-down and still-noticeable diacetyl, anyway!). It definitely has a bit of buttery flavor and the oily mouthfeel. The weird thing is, it is a Saison that I fermented for three weeks, starting around 68 and ramping up to 79 after two weeks, then leaving there (room temp) for a third week. I figured this third week at the high temp would be the D rest needed to avoid it. I used Safbrew T-58, properly rehydrated... But pitched at room temp (78*) into 60* wort. I'm thinking that may be the problem/cause? Thermal shocking of the yeast that killed some off (the one dry packet should have been enough based on the yeast calc i used) or stressed them enough to produce more diacetyl than they could effectively clean up? OG was 1.060 and SG was 1.012 (for 80% attenuation, which wasn't apparently affected by the possible yeast shock/death/underpitch, as that yeast lists 75% attenuation).
I went ahead and bottled at the three week point, adding enough sugar to get 3.5 Vol CO2 (I figured if the yeast hadn't cleaned up the diacetyl after that time and temp, keeping it for a week or so more wouldn't help much... Anyone have the opposite experience? Also, I'd never tasted diacetyl before, and wasn't sure - or more probably was just in denial! - and had everything ready and set up to bottle anyway, so just went ahead and did it - maybe a mistake?). I just tried one (after only 11 days carbing at room temp and one day in fridge - I know that's less than the three weeks and 2-3 days each I'm aiming for, but just wanted to check)... The carbonation and colder temps do lend a reduction in the taste of the diacetyl, but after it sat and warmed/flattened for a bit, it was still very apparent.
Do you think more time bottle conditioning (there are still active yeast in there, carbing it up, obviously) / aging will help reduce the oily buttery yuck-flavor, or should I just chalk this one up to my first "off" batch (its only my fourth, so I'm just happy I made good beer up til now!)? Is there anything else I can do to make it better at this point? Or for future batches (beside trying to match my yeast temp to my wort temp better at pitching, as noted)? It is still drinkable, just obviously flawed... I wouldn't pour it out - but would force myself to drink them as punishment to learn the lesson so as to not (hopefully) do it again!