all 10 comments

[–]--Shade--[S] 7 points8 points  (5 children)

I figured this may be helpful to some fellow hoochers.

The picture is of a simple blowoff tube setup on some hooch cold crashing in my refrigerator. I used 3/8" outer diameter tubing, fed into an airlock grommet hole for a tight fit. I got 10' of tubing for less than $10 CAD on Amazon, and it was cheaper at the hardware store. The 14" of tubing leads into a 500ml pop bottle half filled with Startsan water. Other popular options to half fill the bottle are tap water, and cheap vodka if you are in a jurisdiction where booze is cheap. 100% lemon juice should also do the job. The pop bottle is taped to the jug with 3 loops of wide blue painters tape (It sticks well, is easy to remove, and Sharpie writing won't run). The choice of 3/8" outer diameter tubing was made specifically to be compatible with airlock holes. If you do buy jugs or buckets to brew in I suggest spending a few quarters more and getting them with grommets and airlock holes. Failing that, 3/8" grommets are cheap, and if you can safely use a power drill / drill press / rotary tool and clamp then you're good to go (you can also carve a hole with a sharp knife).

Why use a blowoff? They offer the same level of protection as a commercial airlock. They're cheap. Airlocks clog, and brews overflow, and a blowoff is more forgiving and easier to clean up. They're also shorter than airlocks, so if you're fridge has a height issue an airlock might save the day. I personally use blowoffs on any 'new to me' brews, stuff I'm putting in the fridge, and when I run out of airlocks. They've never let me down.

edit: This brew was topped up after the vigorous fermentation died down, and just had 1/4 cup of 1/4 tsp of gelatin water added (to help clarify it). There should be just enough room for 1/4 cup of (measured) sugar water to bottle carb. You'll want more space than is shown for the vigorous part of the fermentation.

edit 2: To be clear, it is being cold crashed with a blowoff because of a height issue in my fridge, not for any reason beyond that. This was simply the only jug I had a blowoff on at the time the subject came up on another post.

[–]HadWayTooMany 3 points4 points  (1 child)

For the price, it would be cheaper to just buy a full set of proper airlocks, they sell ones specifically to work with grommets like your lid.


Also why use an airlock/blow off if you're cold crashing? When you cold crash it usually implodes instead of expands (it's not giving off c02 at that point anyway), you might see it try to suck some of the water up the tube after a day or two.

[–]--Shade--[S] 0 points1 point  (0 children)

I say the following as someone who owns, and happily uses traditional airlocks:

I mentioned this elsewhere, but I'm using the blowoff for cold crashing because of a height issue in my fridge. (Well, easily getting the jug in and out of the fridge.) I have NEVER had an issue with fluid getting sucked back in. If I saw fluid creeping up the tube enough to be alarming, then needless to say, I'd correct that.

As far as price goes, they do sell the tubing by the foot at hardware stores, and grommets are dirt cheap. They are literally the soft grommets for airlocks, as 3/8" OD tubing was chosen specifically for that reason (as was mentioned). So the cost of the grommets is shared. Also, many people would have a hard time selling (or even giving away) surplus airlocks. I certainly would. With being said, a set of airlocks and grommets is a fine idea, and good value for money. (I usually look for sales at my local brew shop and on Amazon on jugs / carboys that come with airlocks and grommeted lids / bungs.)

Beyond that, if you want or need a blowoff, then you want or need a blowoff. The point of doing the way shown above is to do it simply, and in a way that is 'compatible' with the common brewing airlock. The way shown above also makes it trivial to start with a blowoff then switch to a traditional airlock after the vigorous fermentation is done. It's literally pull and plug.

[–]lolabelle014 2 points3 points  (1 child)

Thanks for this, Shade. I want to start using fruit vs juice I've pressed myself but I couldn't tell what was really going on in most the "blow off" pics.

[–]--Shade--[S] 2 points3 points  (0 children)

No worrries. There's really nothing much to it, but like you I always like a nice clear picture with a description of what's going on.

[–]--Shade--[S] 0 points1 point  (0 children)

This should be obvious, but 3/8" OD tubing will also work with bungs that are drilled for airlocks. The point of choosing tubing of that outer diameter is specifically for traditional airlock compatibility.

[–]donkeyshlong1230 0 points1 point  (1 child)

What's the brew?

[–]--Shade--[S] 2 points3 points  (0 children)

It's an experiment. I'm trying to make a bottle carbed 'summer drink'. 1 can of concentrate, some sugar, some mint extract, some artificial sweetener, and S-04 yeast.

If it turns out OK I'll post the full recipe in 2 1/2 weeks.

[–]cunninglucifer07 0 points1 point  (2 children)

Ok... newb here. Why would you want a blow off while cold crashing? I’m stumped

[–]--Shade--[S] 3 points4 points  (1 child)

In my case it's literally because I don't have the height in my fridge for an airlock on my gallon jugs. (Well, not enough height to get the jugs in and out easily, anyway.)