Blow-off tube VS airlock

Discussion in 'Beginners Brewing Forum' started by Jonny the Brewer, Jun 8, 2020.

  1. Jonny the Brewer

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    Hi guys a lot of websites say to replace the blow off tube with an airlock after 2-3 days... Why is this? Does it matter if I don't bother?

    Thanks

    Jonny
     
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  2. BrewPatgonia

    BrewPatgonia Active Member

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    It doesn't matter if you don't bother with it.
    that being said, the blow off tube isn't needed once fermentation has become less violent, it makes a nicer setup and look with just an airlock.... as well as the slower fermentation (activity) is easier tracked, monitored with an airlock.
     
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  3. BarbarianBrewer

    BarbarianBrewer Well-Known Member

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    I do both. It depends on where the fermentation vessel is rather than any beer-related reason. If it's in the chest freezer I usually leave the blow-off tube in place; mostly due to being out-of-sight out-of-mind. Now that I am without my chest freezer (fermentation chamber) my carboy sits on the basement floor. So I switch to the airlock when active fermentation subsides just to reduce the chance of kicking the 1 gallon jug that the blow-off tube goes to.
     
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  4. Craigerrr

    Craigerrr Well-Known Member

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    I haven't used a blow off tube since I got my speidel fermenters, TONS OF HEADSPACE. Before that I had a couple instances where I just left the blow off tube in place. When it came time to cold crash, I changed the temperature on controller, only to realize later that the starsan got sucked into the beer. One jug, two fermenters. It was easy to tell which fermenter sucked up the starsan come tasting time. It was drinkable, but dissapointing.
     
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  5. BarbarianBrewer

    BarbarianBrewer Well-Known Member

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    I can't say I learned the hard way (because the clean up was minor) but I did learn that sometimes, tons of head space is not enough. I have been pushing the envelope with volume in my 30L Speidel and put almost 9 gallons of wort in. The next day, the giant airlock was full and overflowing! :eek: Obviously I went to an overflow tube for a couple days.
     
  6. Head First

    Head First Well-Known Member

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    If cold crashing definitely replace tube with an airlock but if you don't change temps not a big deal.
     
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  7. Craigerrr

    Craigerrr Well-Known Member

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    I should have noted I brew 10 gallon batches so I put 5.5 to 5.75 gallons in each of two speidels.
     
  8. Jonny the Brewer

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    Thanks everyone! Pleased to know it's mostly for practical reasons rather than much else.
     
  9. Hawkbox

    Hawkbox Well-Known Member

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    I use SS Brewtech brew buckets and it's got a permanent blow off tube attached to it.
     
  10. Frankenbrewer

    Frankenbrewer Active Member

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    For 5 gal batches, I always use a blow-off tube even though I use 6.5 gal big mouth bubblers and Ss Brewtech fermentation conical.
     
  11. ^Tony^

    ^Tony^ Active Member

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    I brew 5.5 - 6 gallon batches. After my first blow out (the pressure blew the cap off the air lock and spewed krausen 4 feet up my basement wall....there is still a stain on the sub-floor :rolleyes:) I started using a blow off tube and a 1 liter orange juice bottle half filled with starsan. I used to swap it for an air lock after the fermentation calmed a bit but it was really more for looks than any thing else. Now I don't because I'd rather minimize the O2 exposure that happens when you take the blow off tube off and put the air lock on rather than have a pretty set up. I know it is small detail but everything helps.
     
  12. Semper Sitientem

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    I always use a blow-off tube for the first three or so days until activity subsides, then I change to a bubbler. Past experience tells me that, in my set up, a bubbler can’t handle the initial activity. I’m not concerned when I switch out because it literally takes one second and fermentation is still taking place so there is a layer of CO2 and positive pressure that keeps out any oxygen.
     
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  13. Sunfire96

    Sunfire96 Member

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    Any preference out there for a 3 piece or S shaped airlock if they're the same price? I've heard 3 piece are better for cleaning and sanitizing
     
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  14. Mark Farrall

    Mark Farrall Well-Known Member

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    I've got both. More parts to the three piece. S shaped harder to get dry. Wouldn't have thought one was obviously better cleaning wise than the other. I end up using the s shaped the most as it fits on to my oversized blow-off/CO2 collection chamber, but the three piece would get in the way.

    I've seen the three pieces used in strange ways that you couldn't do with the s shaped airlocks (mainly connecting hose to places it probably shouldn't be connected to). One of each?
     
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  15. BOB357

    BOB357 Well-Known Member

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    It's a lot easier to clean the blowoff tube if it's used for a shorter period of time. Outside of that, it really doesn't matter unless you're cold crashing and want to avoid suck back.
     
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  16. Semper Sitientem

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    I prefer the 3 piece for the reasons you stated. I also think they work better because of the design and they hold more liquid, IMO.
     
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  17. BOB357

    BOB357 Well-Known Member

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    I use S type airlocks. No suck back and they don't get in the way when installing/removing the temp probe from the thermowell. There are some out there that are so cheaply made that they break when you try to remove the cap, so I advise you only buy from reputable suppliers.
     
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  18. Hawkbox

    Hawkbox Well-Known Member

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    The 3 piece ones are easier to clean, the S shaped ones don't pull back liquid if you cold crash as Bob mentioned. They both work fairly well but I don't use them anymore since I have buckets with hoses permanently attached.
     
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  19. ^Tony^

    ^Tony^ Active Member

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    I have a couple of both but I'm in the 3 piece camp just because I think it is easier to clean and dry. In the end I think it is just a matter of preference. I hardly use either one now. I just keep my blow off on for the entire ferment.
     
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  20. rwinzing

    rwinzing New Member

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    Suck back would be the main reason to replace imo.
     
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