How much water to add after boil?

I've brewed about 6 beers now and I'm on another now, but just had a thought. I have a pot capable of a 3 gallon boil. I'm using 5 gallon kits. After I've boiled my 3 gallons, how much water do I add to the primary? Do I just add enough water to the 5 gallon line or do I compensate for boil off and only add 2 more gallons no mater where it comes up on the primary?

Top off to five gallons.

You put your wort in the fermenter, and fill it til you get to 5 gallons. Anything lost will be made up when you get to that 5 gallon mark.

I just didn't know if that would 'water down' my wort. My beers have always turned out excellent t, just didn't know if I was not getting the full potential from my wort by adding too much water. Thanks.

Is the 5 gallon mark the correct goal or should the target OG be what I shoot for?

From what I've been told, you work your way up to the 5 gallon mark while keeping an eye on your og making sure not to go out of the range.

There have been times where I have had to go to 5.5 or 5.75 gallons to hit an expected gravity. I am an extract brewer right now.

nasty_rabbit said:

Is the 5 gallon mark the correct goal or should the target OG be what I shoot for?

Click to expand...

scorpionc53 said:

From what I've been told, you work your way up to the 5 gallon mark while keeping an eye on your og making sure not to go out of the range.

Click to expand...

In theory you should top off to the correct OG. However, if it's an extract kit designed for 5 gallons, 5 gallons should be the correct OG. As long as you get your volumes right and add all the fermentables you're supposed to (ie don't forget to add something and don't add anything extra), the only way it'll be off is if whoever supplied the kit/recipe messed up.

Top-off water makes getting an accurate reading very difficult if not impossible. What you could do is take a gravity reading after you chill the wort, but before you top off. With that gravity reading, and the volume of the wort prior to top off, you can do some very easy math, and either know what your gravity at 5 gallons would be (accurately), or figure out exactly where you need to top off to in order to hit the OG you want.

I'd still keep an eye on og. I just filled to 5 gallons once and my og was way off.

Qhrumphf said:

In theory you should top off to the correct OG. However, if it's an extract kit designed for 5 gallons, 5 gallons should be the correct OG. As long as you get your volumes right and add all the fermentables you're supposed to (ie don't forget to add something and don't add anything extra), the only way it'll be off is if whoever supplied the kit/recipe messed up.

Top-off water makes getting an accurate reading very difficult if not impossible. What you could do is take a gravity reading after you chill the wort, but before you top off. With that gravity reading, and the volume of the wort prior to top off, you can do some very easy math, and either know what your gravity at 5 gallons would be (accurately), or figure out exactly where you need to top off to in order to hit the OG you want.

Click to expand...

Yes. In the case of topping off with water, in an extract batch go by the volume, YOUR GRAVITY WILL BE CORRECT even though your hydro reading doesn't appear to be. Read this.

Attention new brewers, yes your original gravity reading is wrong. Don't panic.

Extract brewing is FOOLPROOF, top off to your correct final volume and the real gravity will be correct.

The magic of brewing is that Volume and gravity are dependent on each other.

Your beer is exactly stronger by the amount of water you are missing, so if you make it up with water, then the gravity will correct itself. And in the case of extract, all you have to top off to the target volume, you don't njeed to figure out how much, just top it off.

Same if you have to high a volume of water, your beer is exactly weekend by the amount of water you over shot. You can fix that by boiling further to concentrate the wort to the volume you need. (this is more for AG brewing.)

Every brewing software has a tool called a dillution calculator to help people figure out how much water to top off, when the miss their gravity in all grain brewing. If you plug the numbers of even an extract batch into the software you will see how this corrects itself.

It happens all the time. When you calculate your gravity of your current volume and you then use the dillution tool in beersmith to calculate the gravity after toppiing it off with the amount of water you are missing, you almost always come back to what the original gravity should be. I've topped off when necessary and the beer indeed has turned out fine.

scorpionc53 said:

I'd still keep an eye on og. I just filled to 5 gallons once and my og was way off.

Click to expand...

Read the link I just posted, and you'll see that more than likely despite what your hydromter may say, the REAL gravity will only be correct if your total volume is correct.

Revvy said:

Every brewing software has a tool called a dillution calculator to help people figure out how much water to top off, when the miss their gravity in all grain brewing. If you plug the numbers of even an extract batch into the software you will see how this corrects itself.

It happens all the time. When you calculate your gravity of your current volume and you then use the dillution tool in beersmith to calculate the gravity after toppiing it off with the amount of water you are missing, you almost always come back to what the original gravity should be. I've topped off when necessary and the beer indeed has turned out fine.

Click to expand...

(not directed at Revvy but the others on this thread)

The math in those calculators is actually very very simple.

gravity x volume = gravity 2 x volume 2 (expressing gravity as "gravity units". Basically 1.048 would be 48, and 1.072 would be 72).

So if you've done your boil, and you have 2.5 gallons of wort, and your gravity reads 1.090, and you want a 5 gallon batch, 90 x (2.5)=5 x (your OG). You come up with 45, or an OG of 1.045 if topped off to 5 gallons. Alternatively, if you don't care about the volume but want an OG of 1.065, it works the same way. You'd get 3.46, the volume you want to top off to in order to hit that OG.

And it works the same way for AG brewers (or anyone doing full boil, but most critical for all-grain) to scale down the volume, so you know before the boil whether or not you're going to hit your target gravity, and you can either adjust your boil time, your volume, or add more fermentables to make sure you're spot on.

I do partial boil all-grain (since my stove can't boil more than 5 gallons), and this formula makes life so much easier. No more second guessing my gravity readings.