Airlock or Towel?

What do some people use an airlock and some use a towel to cover the carboy? Can they be used interchangeably?

Thanks

Hmm...a towel? I've often used sanitized aluminum foil, but towels are usually pretty nasty (at least around my house). People often wrap carboys with towels to prevent temp swings. Is that what you're seeing maybe?

A towel goes on the PRIMARY (bucket) fermenter so that you can get to it and the rapidly generated gasses and foam have a place to go.

An airlock goes on the SECONDARY (carboy) fermentor to keep air out.

hey there doctorcad....just curious....why a towel on the bucket, and not the lid with an airlock??...we are talking about the ail pail arent we? , I am a bit confused..(and yes a rookie)...so I guess you are saying , if you dont have a lid with an airlock ,,a towel would be a sufficent subsitute??...is this correct?...

A towel simply keeps the big bugs out while still allowing you to stir or check or add when you need to. I usually put the lid on but not snap it down and I cover the airlock hole with a piece of napkin, but a towel works too.

I tested this out last year... I made one batch that I covered loosely with the bucket lid and one batch with the lid snapped on with an Air Lock. After one week I removed the lid off both and found that the gravity was about a half percent lower on the bucket with the lid loosely coving it. It wasn’t much of difference for me to care...

I would say if you are fermenting in a high traffic area like your kitchen, then use an Air Lock and allow a little more time to ferment. The main thing would be to keep contaminates out of your Must... towels don't provide much protection but they allow your Must to breath.