Full Boil Advice

I brewed Dead Ringer extract this weekend. This was my 3rd brew and my first full boil. I started with 6 gallons of water but by the time it reached the primary fermenter, it was only about 4 to 4.5 gallons. I know some boiled away and some was lost to the sludge on the bottom. Should I start with more water in the boil or should I just add more water to the primary fermenter to bring it up to 5 gallons? I used NB’s 10-gal megapot with the valve. The valve sits up about an inch but it was all sludge anyway? All insights are welcome. Thanks.

stirred but not shaken,

If you’re going for full boil, then you’ll want to start with more water. After a few brews you should be able to dial in your system to hit your volumes dead on. Having said that, there’s nothing wrong with topping off the fermentor, it’s just not “technically” a full boil anymore. You’ll have slightly less hop utilization this route, but it works.


when I want 5 gal into the keg I formulate the recipe for 5.5 gal. you will loose some beer when you leave the trub behind in the kettle and during transfer to your bottles or keg. and I also add 1 gal extra for evaporation during boil. My total boil volume for a 5 gal batch is between 6.5-7 gal depending on the beer.

You also have to account for the volume of the extract you’re adding which changes with every recipe. This is why it’s better to aim for under 5 gallons into the fermenter so you can top off. Otherwise you risk getting a lower OG due to too much volume.