Can you add foam control once fermentation has started?

[bgough]

OK, so maybe I'm just being lazy, but I don't want to rig up a blow off tube for my bavarian hefe that's inching it's way towards my airlock. Can I just drop a few drops of foam control in my carboy, or are there sanitation issues with this?

 

[pjj2ba]

Go ahead. After adding the drops, I'd let it sit for a while and let the bubbling CO2 help push out any O2 that got in. Then I'd give the carboy a good swirl to mix the anti-foam in.