Hello. Im very new to home brewing. Brewed several kits this past summer and have gotten a couple batches that i felt were drinkable. Needless to say im addicted to this hobby. Im interested into starting the all grain process. Ive been buying everything i need and reading a lot about the process however im still unsure about a few things. Like how much strike water you use, how much sparge water is needed, how much you need to start your boil and how do you know you have enough fermentable sugars in your wort? I have two 15 gal brew kettles and i will be using a 10 gal igloo round cooler for my mash tun. Also is there a difference between a lauter tun and a mash tun? Or do ppl just use different terminology for these? Thanks in advance.
I'd recommend for AG beginners to use a ratio of 1.5 quarts of strike water per pound of grain for mashes. There's reasons to have thicker mashes or thinner mashes, but for starting out just go with 1.5 quarts of water per pound of grain.
Calculating volumes of all of this stuff is made easier by using programs like BeerSmith or Brewer's Friend, but if you're the type of person that wants to know how to do it without the programs...
Each pound of grain will take up .08 gallons of space in a mash tun. So if you were to mash with 1.5 quarts of water per pound of grain, in your 10-gallon mash tun you'd be able to hold just about 22 pounds of grain plus the strike water.
22 pounds * .08 = 1.76 gallons of your mash tun volume taken up by your grains
22 pounds * .375 gallons of strike water per pound of grain = 8.25 gallons of your mash tun volume taken up by the strike water
1.76 gallons + 8.25 gallons = 10.01 gallons.
If you had a recipe that required more than 22 pounds grain for a batch, then you could modify the quarts-to-pounds ratio lower. With a 1.25 quarts-to-pounds ratio you could get about 25.5 pounds of grain plus the strike water into your mash tun.
So as you can see, your volume of strike water is dependent on how many pounds of grain that you need in your recipe. If you have 10 pounds of grain for a 1.5 quarts-to-pounds ratio you'll need 15 quarts (3.75g) of strike water.
So that's the water and grains going in. Wort coming out is a different story, since the grains are going to absorb water and not let it go. Typically, grains absorb about a pint of wort (.125 gallons) per pound of grain in your batch. 10 pounds of grain with 3.75 gallons of strike water means you'll only get 2.5 gallons out, not including the deadspace of your mash tun.
Your batch sparge volume should be the difference in between how much wort you get out of the mash's first runnings and how much more wort you need for your pre-boil volume. So now all you need to know is how much pre-boil volume you need.
To answer that, it's easiest to work backwards in the brew day. I'll use my own equipment numbers as an example, since I already know my system.
Let's say that I want ten gallons of finished beer going into my kegs.
I lose about a half gallon of beer from each 6.5 gallon carboy that I use from taking hydrometer samples and from leaving some trub behind in each of the carboys. So I actually need 11 gallons of beer going into my carboys. The amount going into the fermentors is called the "batch size."
I lose about a half gallon of wort due to the deadspace in my boil kettle and from tubing, so I need 11.5 gallons of cooled-down wort at the end of the boil.
11.5 gallons of wort loses about 4% of its volume from boiling temps to room temps, so that means if I have about 12 gallons of boiling hot wort and I cool it down I'll have 11.5 gallons of wort. So I need 12 gallons of boiling hot wort at the end of the boil.
My boil kettle boils off about 2.25 gallons of wort in an hour boil (yes, that's a LOT of water, but I have fat wide pots). So I actually need 14.25 gallons of boiling hot wort at the beginning of the boil.
Going from mash temps to boiling temps means that the wort is going to expand about 2%, so if I have 14.25 gallons of boiling hot wort, then I need to subtract 2% of that volume (about a quarter gallon) to give me the magic "pre-boil volume" I'm looking for, which is just about 14 gallons of wort.
To recap:
14 gallons of wort at the end of the mash
14.25 gallons of wort once that gets up to boiling temps (before the boil really gets going)
12 gallons of wort at the end of the boil
11.5 gallons of wort after cooling it off
11 gallons of wort going into the carboys after leaving some behind in the boil kettle and tubing
10 gallons of wort going into my kegs after leaving some behind in the carboys and hydrometer samples
How much water YOU need will be entirely dependent on your own system and processes. You'll need to do a "water run" and find out how much water you lose each step of the way.
"How do you know if you have enough fermentable sugars in your wort?"
Well, that really depends on the style of beer you're shooting for.
Yes, there's a difference between a mash tun and a lauter tun, but most homebrewers use a vessel that does both things, so they're called MLT's or mash lauter tuns, but yes, often times we do incorrectly call them mash tuns for short.
