20L Mash - Make 40L wort by mixing in cold water

[jydell]

Hi Guys

I have done some searching with limited success. I am about to brew 40L (2 fermenters) of mid strength beer (receipe is all grain + sugar). .

Instead of doing 2 seperate 20L batches I was wondering the pro's and cons of doing one 20L Batch at target 1060 gravity (have calculated the grain will fit in malt pipe of my Braumeister) and split 50% into each fermenter with 10L of cold water. The mixing with cold water will bring gravity to target 1030 where I want it.

Pro's (I can see are)
1: 1 mash instead of 2 saves time and effort
2: 50% cold water to mix in will help chill the wort to 18 degrees rapidly
3: No hot side airation issues as will add to cold water (no air contact)

Con's
1. sterilization of cold water may be required (so pre boil it)
2. ?

Any advice / thoughts on this would be appreciated. I am assuming this is not too different to those 10L wort cubes you can by at the brewshop and add water to in the fermenter to get to 20L.

 

[stm]

Spot on jadell. It's just like a fresh wort kit, or indeed like the old kit, extract and partial brews that I used to do.

The con is not really a con - as long as it is reasonably clean town water you are adding, then not a problem. Everyone except us all grain purists (from kits upwards) add cold water to their FV to dilute the wort.

 

[stm]

(I'm impressed - joined in 2008 with one post so far!)

 

[AntonW]

Give it a try i say. Some of the larger brewers do it after fermentation because it allows them to have smaller, well, everything.

I've done it before fermentation and after, and I've found that it works pretty well in both cases.

This is what I've done:

Diluted a 1.065 OG wort to 1.0325 before ferment. The end result was good, But I found it a bit watery, although I expect I would have found the same beer, if brewed to 1.0325, a bit watery also, but maybe not quite so much.

Diltuted worts between 1.060 and 1.095 by between 1/2 and 1/4, after fermentation. I did this by adding between 9 and 5 litres of water to the keg (use a siphon to avoid splashing if you add the water after the beer). This worked out well enough that I'd do it again, and I wouldn't bother diluting before the ferment.

I did the dilutions because I had a mismatch between the size of my HLT, MT and BK, and got sick of making really strong beers, and because I felt like I was wasting my time to make a smaller beer when I could make a strong beer, and dilute some of down to a smaller beer, and have even more beer.

Depends where you are, but most Aussie water is sanitary to start with. You could try not boiling it, and if that doesn't give you the results you're after, boil it next time. I didn't boil it, and generally treat the water as sanitary and haven't had any problems. You can test your water by putting some of it aside in a sanitary jar, and if it grows anything then you know it's not sanitary.

In case it hasn't occurred to you, make sure to scale your hops appropriately.

Other people may have different experiences, but I've found that dilutions are simple don't noticably reduce the quality of your beer.

Good luck.

 

[jydell]

Im a "Long time Listener first time caller".

Thanks for confirming my suspicions brew master. I am now thinking of regularily doing 15L mashes and adding 5L of cold water to fermenter to get the temperature down quickly. Instead of my normal 20L Mash.

 

[stm]

Yes, as Anton suggested, make sure you scale your hop additions for the higher gravity.

 

[n87]

curious on the hops, would you use the same amount of hops that you would if you did a full volume boil of the desired volume?
or do you need to adjust for the higher SG?

 

[lukiferj]

Im a "Long time Listener first time caller".

Thanks for confirming my suspicions brew master. I am now thinking of regularily doing 15L mashes and adding 5L of cold water to fermenter to get the temperature down quickly. Instead of my normal 20L Mash.

Back in my extract days I used to half fill my fermenter with boiled water and then put it in the fridge to chill. After doing a small extract boil and pouring into the cold water, it would get me pretty close to pitching temperature straight away.

 

[stm]

curious on the hops, would you use the same amount of hops that you would if you did a full volume boil of the desired volume?
or do you need to adjust for the higher SG?

The latter - utilisation is lower the higher the gravity (but not directly proportional) - some googling will give you some useful background info, eg:

http://www.realbeer.com/hops/research.html

 

[Bribie G]

Doing a higher gravity brew, more sugars will remain trapped in the spent grains so you will need to use more grain doing one high gravity brew than doing two separate midstrength brews. If you have room in your boiler / fermenter then a longer sparge would be the go.

 

[marksy]

I make double batches and fill 2 x cubes (1.057) and then dilute down to 20L each. I use beersmith to make a recipe based off 32L and then change it to 40L to see the est abv, IBus and SRM

 

[klangers]

High gravity brewing is extremely common commercially - so there's no reason why it wouldn't work!

Give it a go and let us know how it goes.

 

[NewtownClown]

Search for "High Gravity Brewing". It has been going on for a long time.
Forget about trying to sterlise the top up water, you could bring it to a boil to remove chlorine if that is an issue with your water.

Also search for "parti-gyle brewing" which allows a brewer to produce two (or more) different brews from the runnings

 

[dblunn]

Hi, the only problem I can see with diluting after fermentation with tap water would be the dissolved oxygen causing oxidation (beer goes stale quickly). If you boil the water first then the oxygen would be driven off and as a side benefit it would be more sanitary also.
Dave

 

[Bribie G]

Hi, the only problem I can see with diluting after fermentation with tap water would be the dissolved oxygen causing oxidation (beer goes stale quickly). If you boil the water first then the oxygen would be driven off and as a side benefit it would be more sanitary also.
Dave

Exactly. The commercials use deoxygenated water to bring their beers down to "sales strength".

 

[rude]

Just diluted my 90%pils 10% wheat mash got a stuck first runniings stirred sparged and first time with Best Maltz came out 1060 :blink:
So diluted with 4 litres of boiled water
The first mash I did before the above ( back to back brews)100% pils came out 1054 og put 2 litres with this
After reading this thread it has me thinking not a bad way to go got 28 Litres in the first one 26 Litres in the second bonus more beers
Not much head room though in the fermentor