BROUPON #2: Raymond - Brewing 10 gal on a 5 gal system...

Calling all readers. If you have related experience, please consider helping Raymond out.


Gearing up for the spring party season. I don’t get the chance to brew often, so I am looking for a decent workable method to net 10 gallons on my 5 gallon system, utilizing only one boil.

I have a 10 gallon Gatorade style MLT, using a steel braid and no false bottom. My boil kettle is 7 gallons which I usually max out at 6.25 to 6.5 gallons pre boil. Still brewing on the ol’ electric stove in our kitchen. I have plenty of room for a 10 gallon sized mash, but I don’t have the boil volume, nor the time (patience?) for two boils/cools. My best idea so far was to boil a higher gravity wort and then top up to 10 gal with 2nd/3rd runnings instead of all water.

I’m looking at a low to middle OG (1.050 max), something like an American Special Bitter, mostly two row and c-60 or c-80, a charge of high alphas early in the boil, bunch of late hop additions, US-05. I have beersmith as my software package, so I should be able to ballpark my boil additions based on the gravities of my preboil and extra runnings; provided my following assumption is correct:

Gravity of wort is linear. 5 gallons of 1070 wort blended with 5 gallons of 1030 runnings will equal out to 10 gallons of 1050 wort? Is this correct?



Hey there Raymond,

Hmmm... I'm stepping out of my extract brewing world into your all grain brewing world here so bear with me.

I'm thinking you'll need to boil the second and third runnings. Steriliztion, DMS, etc. Here's an article to help backup that conclusion.


Topping off with good water seems like a better option in your circumstance.

I hope that helps. Thanks for sending in your question :-)

Raymond said...
Good point on sterilization and compounds in unboiled wort. Something I didn’t think about. Was just trying to avoid using flavorless water.
Ok, so to get the end volume that I was looking for I should target 1.080 wort, cut with 1.000 water would net 1.040? I really should just wake up earlier and do two boils, I could make two beers.
Feel free to share on your site. And if you have any better ideas for how to increase volume on a small system, go ahead a let er rip.
My Response
Yeah, I'd say that would do it. If you need to increase the gravity, you could always add some extract at the end of the boil. BeerSmithcan help with late malt additions and hop utilization.
Thanks I'll put this up on the site. Who knows, somebody more knowledgeable might chime in.
Good luck preparing for the party season :-) You're reminding me that I need to brew too.


Steve said...

I don't have beersmith in front of me (at work), but there is a setting in beersmith to account for top off water. You could set that number to X gallons, and it should adjust the rest of your calculations for you. That will take some of the guessing out of it for you, and make it easier to predict the batch.

Adam said...

Thanks Steve!

Steve said...

No problem Adam. Just checked beersmith, and the top off water is located in the equipment screen, in the boiler section.

When you select your equipment for brewday, add in the amount of top off water you want to use, and the final volume you are looking for, and beersmith adjusts the rest for you. That should work for Raymond.