Filling 2 cornies with one Grainfather brew

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ElthamBrewer
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Filling 2 cornies with one Grainfather brew

Post by ElthamBrewer » Thu Apr 15, 2021 9:22 am

Hi all,

Looking at moving from King Kegs, where I can fit 25L into a single keg, into Cornies at 19L, whilst doing brews on a G30 (i.e., 30L capacity). Being lazy/efficient as a brewer, I'm pondering the best way to get the most beer per brew without too many compromises. What do other brewers with 30L systems (GF or other all in one vessels) do? Just brew a batch with a target of 19L out of the fermenter? It seems I have to do the same amount of cleaning and prep for 25L as 19L so might as well do the larger batch.

The default option I was looking at is continue to do 25L batches, and bottle the remainder, having used the king keg for conditioning for 4 - 8 weeks.

However, I was also looking at liquoring back with the following heath-robinsonesque scheme - use a grain bill for 2x 19L batches in the mash, and enough liquor for 2.7 litres/kg. Sparge as normal for a 25Lbrew. The GF default estimates about 3L/hour boil loss and 1L trub loss, which ends up with 29 litres pre-boil, and 25 into the fermenter as I tend to boil for an hour. So, I could add another few litres to top up the boil in the last 15 minutes say to 28L (my max fermenter capacity with krauzen spilling over), and then post-fermentation top up with cooled boiled water to get 38L to fit 2 cornies. Would going from 28L to 38L be just a bit too much watering down?

Other things I'm aware of - increase water required in the mash for the grain absorption, and also hop utilisation vs original gravity (Wheeler in BYOBA gives e.g., 27.8% at 1035 vs 24.7 at 1050), which I'd have to adjust for in the recipe. Assuming I can get my maths all correct, are there any other obvious pitfalls?

Cheers,

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Cobnut
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Re: Filling 2 cornies with one Grainfather brew

Post by Cobnut » Thu Apr 15, 2021 10:21 am

I’ve not tried watering down post ferment, so can’t comment on that. Doubtless someone else will.

I have successfully liquored back post boil (before cooling/transfer to FV). I recently explained my method in another thread (viewtopic.php?f=35&t=83192), but this only addresses getting to the most your FV can handle.

Another approach might be to invest in some 9/10L cornies as well as 19L ones; a 28L batch would give you a 19L and a 9L. Or stick to 23L batch size and use a 5L growler with one of those corny keg style caps like this: https://www.themaltmiller.co.uk/product ... pense-lid/
Fermenting: Sunshine Marmalade
Conditioning: Festbier, Helles Bock
Drinking: Smoky, lager beer, Irish Export Stout, Hazelweiss 2023:2, Cascade APA (homegrown hops), Orval clone, Impy stout, Duvel clone, Conestoga (American Barley wine)
Planning: Kozel dark (ish), Simmonds Bitter, and more!

f00b4r
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Re: Filling 2 cornies with one Grainfather brew

Post by f00b4r » Thu Apr 15, 2021 10:27 am

Don’t liquor back post ferment unless you have a machine to remove the oxygen from the water and keep it that way.

aamcle
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Re: Filling 2 cornies with one Grainfather brew

Post by aamcle » Thu Apr 15, 2021 10:30 am

You can liquor back, as a base line just calculate your hops to provide the require required bitterness in the final brew. It won't be exact you may need to experiment a little to get it perfect.

As above boiled water is best, oxidation is worse in high hop batches so they need extra care.

If I'm going to use a corny I bottle the rest, a little sugar in each bottle, leave warm to carbonate and bottle condition as normal. You don't need your pressure barrels.


Wth. Aamcle

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Re: Filling 2 cornies with one Grainfather brew

Post by McMullan » Thu Apr 15, 2021 10:40 am

The strategy I use (with a BM) to max output volume is figure the upper limit of the boil volume (that avoids a boil over) and maintain it throughout the boil by topping up every 30 minutes or so then a good final top up. Obviously, the recipe needs to be tweaked to counter any effects of dilution. Mash temp a little higher and add brewing sugar (top tip :wink:) and adjust hopping rate relative to expectations of increased boil volume plus final top up. I can get 1.5 kegs of very nice beer. If you want 2 kegs you might have to top up post-boil (in the FV) too. Concentrated brewing is perfectly acceptable and used by traditional breweries as well as big commercials. Ditto brewing sugar - don't listen to all-grain purists in denial.

aamcle
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Re: Filling 2 cornies with one Grainfather brew

Post by aamcle » Thu Apr 15, 2021 12:14 pm

Many of Graham Wheelers recipes use sugar often ordinary household sugar then there are hordes for beers that use various candy sugars and syrups.


Aamcle

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