Originally Posted by The Pol
That surprises me... I have to change the hop schedule, since the length of time at near boiling temps is still giving me isomerization.
ive read for bitter hops, "There is some improvement in the isomerization between 45 and 90 minutes (about 5%), but only a small improvement at longer times ( <1%). (howtobrew)"
also for finishing hops, "When hops are added during the final minutes of the boil, less of the aromatic oils are lost to evaporation and more hop aroma is retained."
but with no chiller, i always have the lid on(wether be on the pot or carboy) so i cant be losing a significant amount due to evaporation(verus a chiller chilling in the pot)?
"Hop resins act like oil in water. It takes the boiling action of the wort to isomerize them, which means that the chemical structure of the alpha acid compounds is altered so that the water molecules can attach and these compounds can dissolve into the wort. The percentage of the total alpha acids that are isomerized and survive into the finished beer, i.e. utilized, is termed the "utilization". Under homebrewing conditions, utilization generally tops out at 30%."