# Can I Do A 40liter Batch In A 50 Liter Keggle?



## Robbo2234 (11/8/11)

Hi Brewers,

I am Looking to set up for BIAB, The plan is to make enough beer for 2 19 litre kegs. I suppose that I need a few litres more as there will be some left with the trub. is this possible in a 50 litre keggle?

Thanks


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## Supra-Jim (11/8/11)

You can always brew over gravity and then dilute with water in the fermenter.

Cheers SJ


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## mje1980 (11/8/11)

Robbo2234 said:


> Hi Brewers,
> 
> I am Looking to set up for BIAB, The plan is to make enough beer for 2 19 litre kegs. I suppose that I need a few litres more as there will be some left with the trub. is this possible in a 50 litre keggle?
> 
> Thanks




Not sure about grain absorption with regards to BIABB etc, but as a 3v brewer i boil 44 litres in mine, which ends up being just a bit more than 2 15 litre cubes, which really hold 17 litres, so 34+ litres finished wort


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## Fourstar (11/8/11)

Supra-Jim said:


> You can always brew over gravity and then dilute with water in the fermenter.
> Cheers SJ




Exactly. I typically brew to 35L over gravity and top-up with 10L of boiled cooled water. As long as you calculate your IBU and OG for the dilution its pretty easy (I think).


OG 1.060
IBU 60
VOL 35L

If you want to reduce to a specific OG, e.g OG 1.050 do the following

35L*60 = 2100 /(new OG)
2100/50 = 42L
42L-35= 7L topup

IBU 60 * 35L = 2100
2100 /45L = 46 IBU


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## andreic (11/8/11)

As others have said, you'll need to brew to a higher gravity, then dilute. I don't think 50L is big enough, especially if you BIAB.

I just did a double batch yesterday in a 60L pot. It was 52L at the beginning of the boil - you have to watch it like a hawk until the hotbreak. But I don't BIAB.

I guess if you BIAB, you could always dilute after the mash, before the beginning of the boil. But with 50L, you can't really start with more than 45L, so allowing for boil off and some loss to trub... you'll be lucky to get the 2 x 19L kegs full.


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## argon (11/8/11)

Can be donequiets easily. I used to do double batch biab in a 50l keggle. Just need to do a dunk sparge to get about 75% efficiency. I used to fill 2x17L cubes then top up with 4L cooled boiled water into fermenter. As is typical with biab and over gravity, you'll need to watch your gravity/efficient ratios. You'll get to a point of diminishing returns with too much grain and not enough water. From experience about 10kg grain for 38L packaged was about right. Any more than that and eff would drop off markedly. 

Now I double batch gravity 3V with an 80L kettle and boiling is totally worry free.


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## drsmurto (11/8/11)

I brew 30L over gravity and then dilute with 10L of boiling water at flameout giving me 40L (2 kegs worth).


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## Robbo2234 (11/8/11)

Thanks guys!

so what will I have to do to the following recipie

3.5kg of British Maris Otter Pale Malt
300g 77L British Crystal Malt
350. British Torrified Wheat
120g British Amber Malt


30g Brewer's Gold/Northdown/Challenger : Boil 60 minutes
30grams. Kent Goldings : Add to boil for the final 15 minutes
30grams Fuggle : Add to boil for the final 1 minute

1 Whirlfloc tab in last 15 minutes of boil

White Labs English Ale or Dry English Ale 

Mash all grains at 150-152F for 1 hour. Target OG: 1.039-1.045 Ferment at 65-68F

is it just a matter of using more grain as if i was doing a double batch and then add the water for it later?


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## stux (11/8/11)

I brew 34L collected into 2 15/17L cubes, diluted to 40L for 38L into 2 kegs.

In a 50L pot.

You want to fill your mash as high as you can, squeeze, sparge etc, then fill your boil as high as you can.

I also top up the boil towards the end of the boil so that I end up with 3L of trub after filling the two cubes

Then the trick is to just get the right gravities and ibus.

BeerSmith can work this out if you just use "Top Up Water" in your fermenter, and possible kettle top up too.


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## Thirsty Boy (11/8/11)

If you want to do "simple BIAB" as described in the main BIAB thread, then no, your 50L pot isn't nearly big enough, you will want more like a 70-80L pot to do double batches and not have to worry about sparging, over gravity or be too limited in the strength of beers you make.

Of course if you are willing to complicate your process with one more of those additional steps, then you will certainly be able to squeeze a 40L batch from your keggle.

Me personally, I'm not a fan of brewing more than a few percentage over gravity, i think its a quality compromise. Quite a few people are making what they consider to be pretty good beer brewing significantly over gravity, so its not something that will "ruin your beer" - but for me, the difference in price between a 50L pot and a 70L pot isn't big enough to justify the extra effort and compromise you need to go through to save the money.

Other people will of course disagree (probably stridently) - but IMO your life will be easier and your beer will be better if you buy an appropriately sized pot at 40-50L for single & around 80L for double batches.


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## mfeighan (11/8/11)

i reckon it is doable, i used to manage 60l out of a 70l pot biab, just topped up with water after all that hot break had settled
probably not the best method but it worked


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## sim (11/8/11)

bit of a waste of gas, but if youve got another resonabley sized pot you can boil whatever you cant comfortably fit in that, and add it back at flame out. This is what ive been doing lately for 40 litre batches (50 litre boiler + 10 litre pot).


sim


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## argon (11/8/11)

Here you go... I knew i've written it down before



argon said:


> right... long post but worth it;
> 
> Yep double batch BIAB can be done in a 50L keggle. I've done maybe a dozen double batch BIABs. TAs said before it's best to be done by adding top up water to the fermenter.
> 
> ...


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## milob40 (12/8/11)

argon said:


> Here you go... I knew i've written it down before


yep +1 on the "having trouble getting the bag out", very tight and awkward if the opening is not full diameter, mine is cut about 30mm short so i can fit a lid.
might have to get me one of those pots from cb for double batches.


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