Birko 30l Hot Water Urn- Is It Big Enough

[Baulko Brewer]

Quick question.

I have the opportunity to buy a 30l Birko for $100. I want to use it for BIAB. As I only do single batches is this big enough for a 23l wort boil after putting the grain bill in. I note most users have a 40l urn. Its cheap and beggars can't be choosers.

 

[MarkBastard]

You may be able to get a 20L (into fermenter) batch of beer out of it. Just really depends.

I aim for 20L into fermenter. I start off with 30L of strike water and add the grain to that. You'd have to mash thicker and top up with water. It's possible.

For $100 I'd buy it either way.

 

[Baulko Brewer]

Thaks for the quick response Mark. Just the info I am looking for. I assume you adjust recipe to 20l batch. you are right either way i am buying it, just want to make sure

 

[Spork]

I reckon you could do full (21-23 litre) batches.
Just mash with a little less water than usual, then after grain is removed add the rest of your volume and boil.

 

[MarkBastard]

No what I mean is, this is how it works for my 40L urn.

I start with 30L of water in it. I add say 4.5kg of grain. I imagine this bumps up the level to maybe 34L or so? Not sure but definitely over 30L, so on your urn it'd be overflowing if you don't adjust the process.

After I pull the bag out and fully drain it I have about 26L of wort pre-boil.

This boils down to about 22L. I leave maybe 1 litre of crap in the bottom and due to cooling and other reasons I end up with about 20L into fermenter.

You'd be able to say start with 25L of water in the urn, and then after draining the bag maybe do a 5L dunk sparge in another pot (say a Big W 19L pot) and drain that too and in theory it should be similar to starting with 30L.

It's basically possible to do it, maybe a bit more messing around and watching for boil overs carefully.

However even if you later buy a 40L urn it's still going to be handy having this one especially for $100.

 

[stux]

I just did some calculations, and you should be able to get a batch out of it.

Basically, you work out the maximum liquid you can fit in the urn during the mash (ie top up once you have your grain in) right to the brim. You're doing this because thicker mashes result in less efficiency with BIAB, so you want the mash as thin as possible

then when you pull the bag, top up as high as you dare go for the boil, this will give you the best possible hop utilization

you will boil off a certain amount of liquid, if you find you don't have enough at the end of the boil (you'll be able to dilute in the fermenter) then you can always add more liquid during the boil

You should be able to do a full batch, but will probably have to add 4L or so during/before the boil

...

A kilo of dry grain displaces about 1L of water until it gets wet, where it displaces about .7L

So, 5KG will have a dry displacement of about 5L and a wet displacement of about 3.5L

So, if you have a 5KG grain bill and your urn holds 32L to the brim with the lid on, fill up to 27L (32 less 5L displacement), then add back about 1.5-2.5L once you have your grain wet to fill it right up. I would just warm 30L up to strike temp and reserve 3L in a jug

When you pull your bag and squeeze it you'll get about 26-27L of liquid.

That should be okay for a boil.

If you lose 4-6L then you'll be down to 21L or so

Which is why you might want to add back some water during the boil. I find if I crank the boil as I slowly add near boiling water (say from a kettle) it doesn't slow my boil

If you can end up with 25L post boil, then you can get 24L hot into a cube, and 23L into a fermenter.

Of course, if you're kegging you may only desire 20L into the fermenter, which makes everything much easier

 

[RdeVjun]

I'd buy it for $100. Using stovetop BIAB principles you should be easily within 23L batch territory. The method is: add sufficient water to the urn after the grain goes in to fill it, sparge the bag in a bucket (if efficiency is low), boil as usual, dilute at pitching to desired OG. I can do 24L of 1.050 with relative ease in a 19L stockpot, no reason why your 30L urn shouldn't do the same or better. :icon_cheers:
Edit: I picked up a 20L urn for nix yonks ago, quite confident it will do much the same as the 19L stockpot when I get around to it.

 

[Bribie G]

Do a sparge in a bucket on the side (or build a wee lauter tun) and you will be sweet.
For a full sized batch with around the 5k of grains I normally use 33L of strike water in a 40L urn and get acceptable efficiency. However with a 30L urn you are going to have to mash thicker and leave more goodness trapped in the "spent" grains that a sparge will make "spenter" (new word ) and flush out that otherwise wasted goodness. You might need to add the sparge runnings into the urn in stages as it boils down.

And carefully monitor the urn for boilover in the first few minutes but once the initial foam has subsided you can let it rip.

 

[Baulko Brewer]

Well, I bought it last night, got him down to $80 so pretty chuffed with it.

I was cleaning it and checkinng boil times, when a thought occurred to me.

If I put a colander over the heating element, is it feasible to hook my STC-1000 to it to keep mash temps at constant temp. I notice that when full it maintained 68 degrees, when left just off the lowest setting. This way if it drops in temp the thermostat can kick in and bring the heat back to desired temp. Am I the greatest lateral thinker ever or is it standard practice.

 

[MarkBastard]

That doesn't work unless you're constantly stirring the mash at the same time to distribute the heat.

 

[Baulko Brewer]

That doesn't work unless you're constantly stirring the mash at the same time to distribute the heat.

D'Oh!!!

 

[Bribie G]

A cheap kid's sized sleeping bag plus an old single doonah will do the trick. However a curved roasting rack from a kitchen shop plus a paint stirrer to pump the mash up and down will allow you to heat and stir for a mashout, and to do stepped mashes.

 

[big78sam]

Refer to this link for some helpful hints

http://www.aussiehomebrewer.com/forum/inde...showtopic=36935

The urn this thread is actually about is crap but the principles are sound. refer to the attachment in Thirstyboy's post 19. I used this method for a while until I upgraded to a 40L birko.


EDIT: +1 to Bribie's comment. Just lag the urn with sleeping bag/doonah if you want constant mash temps.

 

[Baulko Brewer]

Thanks Guys for the reply's.

Thanks Big Sam, TB's methodology will work exactly how i want it to. (special mention to TB for actually writing it)