How much water is used to brew 5-gallons of beer? I seem to remember hearing somewhere (I don’t remember where,) that you use 4-5x the amount of water as in your final volume. (The lost water going into the grains or used for chilling, etc.) So 20-25 gallons of water is used to make 5 gallons of beer. Does that answer sound right?
It really depends a lot on your system.
Extract, partial boil, and chilling in a water bath: Probably a lot less than that.
All grain, full mash and boil, with an IC chiller: It’ll be more but once again that depends on your system (how much you’re losing to dead space, grain absorption, boil off rate, etc). If you’re using an immersion chiller and running the water off and not recirculating/reusing it somehow you could potentially blow through a lot of water.
Chilling is where you use the most. The grains absorb about 0.1 to 0.12 gallon per pound of grain, So if you brew a 5 gallon batch with 10 pounds of gran you only have 1 gallon or so absorbed.
I have started using a pond pump to recirculate ice water once the wort is in the 90-100F range. This minimizes the water used chilling, especially in the range where the delta T between the tap water and wort is small.
Not much water is “wasted” if you use the hot water from the chiller to clean up your gear, and use the rest to water your plants and trees. Some even use the water to fill the washing machine.
Yeah, I’ve always toyed with the idea of running the chiller output into something like a rain barrel where I could measure the amount. Always chickened out cuz I might find out just how much water it uses.
I use 2 gallons per batch ;D
…and 50 lbs of ice :-\
One of these days I’ll get my own ice maker and try to start working towards cost effectiveness.
That’s on my list. Although, my “icemaker” is gonna be a chest freezer - somewhere to keep my hops, cold air supply for my “son of fermentation chiller” and an icemaker for wort chilling. Oh, in order to get my “icemaker”, I’m probably gonna have to let the wifey keep frozen groceries in it too.
Of course ;D
I take the initial heat out with water from my rainbarrel and then switch to a recirculating ice bath. Still uses the water in the ice, but that is about it. Now the problem is I have to pump in both cases and while it saves water, it surely is an electrical hog.
Well, if you are going to count the water used by the chiller, you may as well start counting the water used to clean and sanitize your equipment too. ???
I want about 6 gallons wort going into my kettle for a 5 gallon batch. With my system I will typically use around 8 gallons of water. I’ve never done partial mashes or extract brewing, though I imagine that would lower your water requirements.
Brewing the beer uses the least amount of water, and as indicated it’s the chilling and clean-up that is the bulk of the usage. My opinion is that I’m not wasting anything- just using what it takes to make the beer. Certainly got my process down and with a recirculating pump can chill my wort from boiling to pitching a bit more quicker so that saves some water there- but not that “conserving” is on my mind at that particular moment.
I brew 12 gallon batches and 50 gallons of water sounds conservative. Loosely measured it by timing the fill of a 5 galllon bucket in the chill process and was a little disconcerted to see how rapidly it got filled. 
Then experimented with chilling from about 140F by using frozen 2&3 liter PET bottles as a basis for the ice-water recirc through my IC. Took forever! Wrong approach. Dead end at my brew capacity unless one is able to accept the hour and half chill time. Now I just freeze up a bunch of ice in the deep-freeze and use that to good effect.