Full-volume Boil Question

[maximus4444]

Hey guys, I'm just starting out. I've been reading and watching as much as I can to start my hobby of homebrew.

I'm curious if I am doing a full-volume boil to get a desired 5-5.5 gallons of wort; how much water should I start off with?

I know that after an hour, there would be (I'm guessing here) about a gallon, maybe more of boil-off.

Is there a way to determine the initial amount of water I would need?

 

[chickypad]

It's dependent on several things, probably the most important is surface area of the pot but also humidity, how hard you are boiling, etc. For reference I boil off about .65 gal per hr in my 5 gal pot and 1.5 in my 20 gal pot. Assuming your pot is around 7-8 gal I would plan on abut a gallon per hr then measure it the first time for future reference.

 

[maximus4444]

Yes, my pot is 7.5 gallons. Great idea.

 

[max384]

It's going to be different for every pot (size, dimensions, metal composition) and every burner (how many BTUs, distance from burner, size of burner), and even the humidity and elevation play a role as well. The best thing you can do is to add several gallons of water to your kettle and do a test boil for an hour. This way you'll have a very good idea of what your boiloff rate is, and therefore, how much water you should start with. Dissolved sugars (wort) will change it a slight bit, but not enough to really matter much.

Here's a good online calculator to figure out volumes that you need (but you'll need your boiloff rate for the calculator):

http://www.brew365.com/mash_sparge_water_calculator.php

 

[BrewerBrad82]

It's going to be different for every pot (size, dimensions, metal composition) and every burner (how many BTUs, distance from burner, size of burner), and even the humidity and elevation play a role as well. The best thing you can do is to add several gallons of water to your kettle and do a test boil for an hour. This way you'll have a very good idea of what your boiloff rate is, and therefore, how much water you should start with. Dissolved sugars (wort) will change it a slight bit, but not enough to really matter much.

I totally agree. Grab yourself some homebrews and boil some water. Its all about calibrating your system!

 

[plumbrew]

It's going to be different for every pot (size, dimensions, metal composition) and every burner (how many BTUs, distance from burner, size of burner), and even the humidity and elevation play a role as well. The best thing you can do is to add several gallons of water to your kettle and do a test boil for an hour. This way you'll have a very good idea of what your boiloff rate is, and therefore, how much water you should start with. Dissolved sugars (wort) will change it a slight bit, but not enough to really matter much.

Here's a good online calculator to figure out volumes that you need (but you'll need your boiloff rate for the calculator):

http://www.brew365.com/mash_sparge_water_calculator.php

+1 on a test boil. I was bored a couple of weekends ago and decided to start out with 7 gallons of water in my pot and let it boil for 50 minutes, add the wort chiller and then go another 10 minutes, cool and then see how much was left. Got down to 5.5 gallons so I know pretty much exactly how much I'm going to boil off in an hour. It's worth the test and takes the guess work out when you're boiling live.

 

[maximus4444]

How much wort then should I strive for if I want to yield 5 gallons of beer? Should I be trying to get 5.5 gallons of wort to account for loss to hops, trub, etc.?

I'll be using leaf hops; and from what I've heard, it sounds like they absorb more water than pellets.

Would 5.5 gallons of wort be a good starting point to yield 5 gallons of beer?

 

[max384]

How much wort then should I strive for if I want to yield 5 gallons of beer? Should I be trying to get 5.5 gallons of wort to account for loss to hops, trub, etc.?

I'll be using leaf hops; and from what I've heard, it sounds like they absorb more water than pellets.

Would 5.5 gallons of wort be a good starting point to yield 5 gallons of beer?

I do 6 gallon post-boil volumes. This leaves enough volume so that I can transfer from primary to secondary, and from secondary to keg without having to worry about coming up short.