Is airlock necessary or is blow off tube enough?

[kojinakata]

Hi,
Just wanted to know whether an airlock is necessary or a blow off tube in a sanitizer solution is enough for primary and secondary fermentation? Brooklyn brewshop video shows using a blow off tube at the beginning of the fermentation and replaces it with an airlock after some time. What is the reason behind this? Will the fermentation continue nicely if blow off tube was kept?

Thanks.

 

[BansheeRider]

Hi,
Just wanted to know whether an airlock is necessary or a blow off tube in a sanitizer solution is enough for primary and secondary fermentation? Brooklyn brewshop video shows using a blow off tube at the beginning of the fermentation and replaces it with an airlock after some time. What is the reason behind this? Will the fermentation continue nicely if blow off tube was kept?

Thanks.

Yes, you can leave the blow off tube. Maybe their blow off tube was dirty from the initial fermentation so they decided to use an airlock.

 

[SIXFOOTER]

Frequently a Blow Off Tube is used in the beginning of a Vigorous ferment because the krausin will stop up an air lock and it will launch off the carboy.
A couple ways around this, more or less. I don't like a blow off tube simply because its more of a mess than I like, nothing wrong with it though.
Use a carboy with sufficient head space that the krausin stays in there, 7 gallon or so for a 5 gallon ferment. This works for all but the most explosive ferments.
I also drill out the holes on the top of the 3 piece air locks to keep the hops from stopping up the holes. In a big ferment you will still get some blow by, but its a simple thing to rinse and reinstall the airlock and it won't launch.
Or, just leave the blow off tube

 

[kojinakata]

So there is no downside for using a blowoff tube till the end of the fermentation other than it taking up more space and being messy. I was concerned about the pressure differences between them. What I mean by that is when using an airlock, the pressure or force that the gas inside the fermenter has to overcome is the pressure created by the sanitizer solution in the airlock. However when using a blowoff tube, I thought it probably is much larger due to the fact that the blowoff tube ends in a cup of sanitizer solution which much more larger than the solution in the airlock.

 

[freisste]

So there is no downside for using a blowoff tube till the end of the fermentation other than it taking up more space and being messy. I was concerned about the pressure differences between them. What I mean by that is when using an airlock, the pressure or force that the gas inside the fermenter has to overcome is the pressure created by the sanitizer solution in the airlock. However when using a blowoff tube, I thought it probably is much larger due to the fact that the blowoff tube ends in a cup of sanitizer solution which much more larger than the solution in the airlock.

No downside.

And you are absolutely right: I'm sure there is more pressure with a blowoff tube. But not so much that it will affect fermentation at all.