My blue ribbon Kolsch was a 10 gallon batch, all grain, with my HERMs system(pics in my gallery). It's one of the simplest beers to make but the fermentation is the key.
18 lbs Pilsner
2 lbs Wheat
.5 lbs carapils
2.5 oz. Crystal leaf hops (4.7% alpha) @ 60 minutes.
Dough in was 135 but...