Blow off tube in place of airlock?

[Wabby]

Just got some new fermenters and they are taller than my old ones, leaving just 1" of room above in the brew fridge.

Could I just put a blow off tube from the airlock hole to a sanitized bottle half full of sanitizer and will this be ok?

Any ideas on size of tube and any fittings to fit normal airlock bung??

 

[terrym]

You don't actually need either an airlock or a blow off tube. You can just crack the lid slightly and allow the CO2 to escape, or krausen to bubble out, although you will need some means of containing the mess arising if it's the latter. See this old thread for pros and cons of airlocks
http://www.thehomebrewforum.co.uk/showthread.php?t=55112
However if you want to go ahead with a blow off tube instead of an airlock the principle is the same i.e. you have a positive seal between the inside of the FV and the outside world which allows gas to only go one way. There are plenty of blow off tube how to's on Youtube. My tube fits over the inner outlet of a standard winemakers type airlock. If you don't have any restriction on the ID of the tube (like me) I suggest you go for a 12mm ID tube which should be big enough to stop krausen blockages. You would tailor the penetration in the lid and how and to what you fix the tube to suit.

 

[Brett74]

I stole an inch off the top of my bottling wand, fit the bung perfectly and then a hose into a big pet bottle.

 

[DoctorMick]

What's the volume of the fermenter? My 30l doesn't fit in the fridge with room for an airlock so I just loosely fit the lid (it's a screw on so very easy) and as there is a load of head space I don't need to worry about blow off (that's why I bought a bigger one).

 

[steveshep8676]

Terrym is right you don't actually need an airlock to brew beer although I have a couple of 20 gallon conicals with blow off tubes into a sanitiser just to contain any mess really. The blanket of co2 produced during active fermentation should be enough to protect the beer from any airborne problems, CO2 being heavier than air it will always remain there. One think to be careful with a blow off tube using conicals is, if you dump trub out of the 2" bottom valve it's possible to create a partial vacuum over the beer and draw in the sanitiser via the blow off tube. Always remove it before dumping trub.

 

[Dutto]

If you do use a blow-off tube just remember that the depth of liquid in the blow-off bottle has to be overcome by the pressure in the FV before you will see a bubble!

So my advice is to ensure that the tube is only about 1cm below the level of the liquid in the bottle. :thumb: :thumb:

 

[Wabby]

I ended up using some left over 10mm plastic central heating pipe andit seems to be doing the trick.

 

[Personal91]

If you do use a blow-off tube just remember that the depth of liquid in the blow-off bottle has to be overcome by the pressure in the FV before you will see a bubble!

So my advice is to ensure that the tube is only about 1cm below the level of the liquid in the bottle. :thumb: :thumb:

its going to be bubbling like nobodys beezwax with that little hehe

but too much and it will allow pressure build up inside the fermenter!

 

[Chippy_Tea]

I only use a small bottle and stand it on top of the FV , i only just cover the end of the tube with water.

 

[Wabby]

Still bubbling away a week in. Longest a ferment has gone, but I am fermenting at 15 so expect the longer time.