I was wondering if anyone can tell me : if I add hops at flame out, how long should I let the wort sit before I start cooling it down with my chiller?? And is there a lot of flavor difference if a add them at the last 5 mins of the boil instead?
Start cooling your wort immediately. There is a difference in flavor vs a 5 min late addition. The less time hops have to boil, the more aroma they will give a beer.
Latest thinking is to cool the wort to about 170-180 F and then add the flame out addition, and let stand for up to 80 minutes before cooling.
I did this recently (steeped for 40 minutes at 170 F). When I racked to secondary after 2 weeks flavor and aroma was great. I do not plan to dry hop this beer to see how it stands up to time vs. dry hopping. Based on the taste I had at racking, it holds a lot of promise.