Drink All You Want, I’ll Brew More

by Tom Altenbach

I picked the title quotation off the Net. It’s great when you have plenty of homebrew on hand and can make that offer. But for successful homebrewers, the product is so good, it’s hard for many to keep an ample supply in stock.

There are two main ways to increase your supply of homebrew: either brew more often, or produce more beer per batch. For most of us with jobs, families, and other interests, brewing more often may not be practical.

What about increasing batch size? Many in the Draught Board are now brewing 10 gallon batches. That’s double the size of the usual 5-gallon batch, for only a small increase in work. But we can do even better.

For those with two 15-gallon vessels and two stoves, it’s easy to turn out a 15-gallon batch of medium strength all-grain beer. Simply brew a concentrated wort, and later dilute with water. That’s the way the megabrewers do it. It’s also the same principle used by many kitchen stove small-pot extract brewers.

This is how I’ve applied it in going from 10 to 15 gallons. I scale up the grain bill by 50%, filling the mash tun to capacity. The mash may be stiffer than usual because of the need for more grain, but that’s OK. I do the same normal sparge to collect 13 gallons of sweet wort. Next I boil it down to 10 gallons of about 1.090 gravity, depending on the recipe.

So far the procedure is identical to brewing a high-strength 10-gallon batch. Toward the end of the boil, I bring an extra 5 gallons of brewing water to a boil in the other pot. Then I dump it in the wort after the finishing hops, and cool as usual. I use a counterflow chiller, and the output goes directly into three carboys. Cooling the whole 15 gallons at once is easier for me than prechilling the 5 gallons of top-off water, but that would work too. The result of the dilution is 15 gallons of 1.060 wort, a decent brew indeed.

There are a few other changes to the brewing process. Don’t forget to adjust your hop bitterness calculations to account for the decreased utilization in concentrated worts. Scale up your hop additions by 50% to start with, then add more to compensate for the higher boil gravity. Refer to the September and October 1995 Draught Notices for instructions on how to adjust the hop rate.

Don’t forget to prepare more yeast to feast on the extra wort.

Finally, the biggest change for me was in getting over the mental block against "watering down my beer." This method still adheres to the Reinheitsgebot and the Alt’N’Bock quality control code for "lite" beer production. If you get carried away with high volume and really want to feel like a megabrewer, dilute your wort by 50% to make a 20-gallon batch of 1.045 lawn mower beer. Corn and rice adjuncts are optional.

With this system I’m actually undersparging, but it’s never hurt my Barley Wines or Dopplebocks. Although my leftover spent grain may be a little sweeter than if I’d run 5 more gallons through it, I haven’t noticed any obvious difference in extract efficiency.

Boiling a more concentrated wort can increase carmelization. My boiler is direct-fired, but the small flames are spread out over the bottom of my aluminum-clad stainless steel pot. With this set up, there is little risk of scorching, and I haven’t noticed any change in my brews due to more carmelization.

Another question concerns the validity of simple scaling recipes for both the male and hops. I’ve done straight linear scaling to go from 5 gallons to 10 to 15, and I’m quite satisfied with the results. By boosting batch barrelage, you’ll need more reasons than mere thirst to have to buy commercial beers.