Air lock vs blow off tube?

Air lock vs blow off tube? could someone explain the difference between the two to me?

the blow off is generally used in the fist 24-48 hours of fermentation. The CO2 production can be impressive during this time, and the by-products of the fermentation can clog an airlock. The blow off tube has a larger diameter and is harder to be clogged.

Essentially they are the same thing. Air lock and blow off tube allow for air/CO2 to escape without any bacteria riden air coming back in.

An airlock is a small piece of equipment used to release CO2 gas while keeping air and other nasties from getting in to your fermentor and ruining your beer although that is not easy to do. A blow off tube is similar in that it lets out CO2 and keeps air out however it is a tube that exits the top of your fermentor and is submerged in a small bottle to complete the airlock. The blow off tube is used when you have a very active fermentation that could cause the fermenter to overflow if not allowed to be released, the bottle than catches the excess krausen that doesn't fit in the fermentor. (I had to rig my last blow off tube because I didn't allow enough headspace and my Apfelwein oozed all over the place with a sticky mess.

sample blow off tube

ok thanks I knew what the difference is in set up, I just wasn't sure where you would use one versus the other. So my next question is if I use a blow off tube can I push the limit of head space or is it best to try and avoid that by keeping plenty of of room for the krausen

You should read my thread and see what happens sometimes EVEN with enough headroom.
https://www.homebrewtalk.com/f37/bit-mess-99129/

I have never used a blow off tube and I have been fine in my very Limited experience. However I plan on using a blow off in my next Brew... Imperial Honey Porter

Its a bigger beer than I usually brew and I think a blow off is in order.

I haven't used an airlock in a couple of years. Blowoff tubes or aluminum foil for carboys - a loose lid on buckets. Simpler and no issues with clogged airlocks. Lots of ways to skin a cat ...

I still have stains on my kitchen ceiling from a blown off blow off tube. (dry hopping and the 1/2 tube got clogged)
I have also had two airlocks blow on me and they do create a royal mess. I would say go with a nice large blow off tube and sleep well at night and no worries at work.

With a blowoff tube, I'll run a 5Gal carboy full to the point where it starts tapering, right at the top of that last marked line on the carboy. I'll usually leave it in for a day or two, or until things calm down, then switch to an airlock. It's worked well for me.

Jif said:

I'll usually leave it in for a day or two, or until things calm down, then switch to an airlock.

Click to expand...

Just wondering.... why not just leave the blow off?
I only have 1 air lock and when I had 2 fermentors going at the same time I just went with a blow off with the end in water.
Since this acts the same as the air lock I have since done this the last couple of brews.

Any reason why I should specifically be switching over to an airlock after initial activity dies down? Just seems easier to leave everything alone.

Thoughts?