[skrag6713]

i've only ever had one batch clog an airlock.  that was a batch that i poured my wort on a yeast cake of nottingham from a previous batch.  other than that i've always used airlocks.

[bluesman]

I use a blowoff hose quite often. I like to use 6 gallon carboys and switch from an airlock to a blowoff when/if necessary. It's usually yeast dependent. I usually don't need a blowoff for American ale yeast or lager yeasts.

When fermenting APA/IPA, I'll use buckets and typically won't need a blowoff hose.

[denny]

I start out with a blowoff on every batch.  Not difficult to do and no problem even if you don't get blowoff.

[Kaiser]

IMO: always

Your want to blow off the Kraeusen. I even top off my beer if I notice that there will not be a blow off

Kai

[corkybstewart]

My fermentor is in a sealed wooden box and I can't see what it's doing so I always use a 1/2" blowoff hose.  I can hear the gas "thump" when it really gets rocking.  When I've tried an airlock I get nervous because I can't hear what's going on and I worry the airlock has blown out(it has happened).

[donredbull]

Right on thanks to everyone for their opinions.

[In The Sand]

I always use a blow-off tube to start.  Then switch to airlocks after the first dry hop addition or when moving to cold crash.