How much water is needed?

[Rincon]

Oh man, the more i do this AG brewing and the more i read the more i realise I know nothing!

So roughly for the brews I've done so far I've used 16l of water for my mash and another 16l for sparging for a 23l batch of beer, after the boil I have to top up a couple of litters.

However Ive never really based that on anything other than the first time I did this AG brewing that's what I was told to do.

Now Im trying to work out what that would have been based on.

Is there a general guide/formula for working out how much water is needed for both mash and sparge?

Thanks

 

[geetee]

I will tell you how I do it and why and I am sure others have their variations and may have different reasons.

Start with your grain bill weight in kg. You will need a water/grain ratio of approx 2.5/ 2.7. I use 2.7 but others may use a more or less stiff mash according to what grains you are using.
Deduct the mash volume from your final target volume to give a sparge volume. Assume that the grain will hold 1lite per kg of grain and add this as extra.

I always assume that this is just an approximate value and will heat extra sparge water and continue to sparge until refractometer shows last running approximately 1008.

Once you boil you will lose water with evaporation according to your kit.
I take the final post boil volume and the final gravity. If gravity is too low you can continue to boil to evaporate off (or add extract) or if high then liquor back to target. I always expect to liquor back at the end, it's part of the process.

I think you can fix your mash ratio according to beer style and then the amount of sparge is whatever it takes to get best extraction to reach your target
Please correct me if I am wrong!

 

[duncans]

I agree with geetee.

2.5l water per 1kg grain for the mash. I do the same again for sparging but I could do more and I think most people do. Only reason I don't is that my kit can't handle a large Boil volume, so I sacrifice little efficiency.

Anyway, 1008 on your sparge liquor and if you measure pH don't let it get too high or you will end up pulling tannins out apparently. I would guess pH 6 would be starting to get too high.

 

[YeastFace]

I have a spreadsheet I'll try to upload later. What is the volume of your mash tun?

 

[YeastFace]

Here you are - https://drive.google.com/file/d/0B5COVFYpSUW_UXVhckw3dl9sQlk/view?usp=sharing

You'll obviously need to amend some things for your equipment. I'd double check the strike water temp on an online calculator as this has been set to my equipment.

 

[Rincon]

I have a spreadsheet I'll try to upload later. What is the volume of your mash tun?

brilliant, thanks!! My mash tun is a 45 litter igloo cooler

 

[Rincon]

Thanks everyone, thats really helpful.

Its funny how much there is to learn yet you can still make good drinkable beer with little knowledge!

Seems ive made some really nice beer with little knowledge but Ive spent a lot of time on here reading and learning, Ive realised that I really have so much to learn - and also getting distracted with so much more i could buy haha

 

[Fil]

loss due to dead space and evaporation are brewery specific, even with 2 identically equiped breweries the evaporation rates can differ.

the only answer is to brew take notes and adjust volumes accordingly to suit, after 2-3 brews you shoud have the info you need.

for the boil off rate (evaporation) havig 2 elements and a dipstick with final target volume marked can help you monitor the progress and switch on/off the 2nd element to accelerate or slow the rate of boil off during the boil.

 

[Bunglebrewsbeer]

All this is handy to know as I'm looking at going down this route soon from my current BIAB set up.

 

[serum]

There's a lot of trial and error but I find 40l gives me the right volume for a 23l batch with a vigorous boil

 

[Bunglebrewsbeer]

Sorted. I have made note.

 

[clibit]

17 litres is a hell of a big loss for a 23 litre brew. Presumably a long boil, but if you lose 5 litres or so to grain absorption that still leaves another 12 to evaporation and trub losses.

 

[Bunglebrewsbeer]

My BIAB I tend to use approx 35l to get about 23. But even that had produced less at times.