I had a Kolsch that didn't drop krausen after 3 weeks. I've heard that cold crashing it will help it to clear and drop, but I didn't try it. I just racked underneath the foam into secondary, since my 5 gallon carboy fits in the fridge for cold conditioning time.
Primary #1:Spruced Winter Warmer #2: Black Currant Wine
Secondary #1:Berry Rhubarb Wine #2: Empty
Kegged: Cascadian Dark Ale
Bottles: Surly Bender clone, Big 50 Barleywine, Framboise Lambic, Dark Belgian Strong, Kicked by a Moose Scotch Ale, Russian Imperial Stout, Sparkling Elderflower Wine, Barolo Wine, On Deck: Orange Pale Ale IV, Hidden Lake Nut Brown, 2H IPA III