What I learned about brew systems at “Big Brew”

On May 3 I was in the parking lot of Maryland Homebrew with a lot of other brewers, participating in their annual “Big Brew” event.

I’ve been doing all-grain brewing for quite a while now, but I have a fairly simple set-up, as did many of the Big Brew participants. But you know homebrewers — they’re a creative lot. People had some pretty fancy rigs. One guy even had the Ruby Street setup.

I spent some time looking at all the different brewers’ gear to get a sense of the benefits of different configurations and methods, and afterwards I tried to come up with a generic diagram of “best practices” for a fancy all-grain brewing rig. Here’s the diagram. Descriptions of all the components are provided below. You can click on the image for a larger version.

Greg Krehbiel's diagram of a generic all-grain brewing system

There are five main pieces of equipment.

  • The hot liquor tun
  • The mash tun
  • The kettle
  • The pump and
  • The wort chiller

There are also two sources of heat, lots of hoses, the frame you put it all on, etc. I’ll explain all that as necessary.

Hot liquor tun — This is where you heat up your strike and sparge water. You can just leave it at that — a simple pot to heat water in — but some people add a coil inside the hot liquor tun to recirculate wort through the hot water. This is helpful to manage the temperature of your mash, but it also helps in getting very clear wort into the boiling kettle because as you re-circulate your mash water, the grains in the mash tun form a very effective filter. It’s like a really long vorlauf.

Mash tun — Many home brewers make a mash tun out of one of those orange or yellow picnic coolers — like the ones you see strapped to the back of a construction truck with bungee cords. But sometimes it’s a metal pot, a converted keg, or something along those lines. The spigot to draw liquid out of the mash tun has to have a filter of some type. Some mash tuns have a false bottom, some have a kettle screen or equivalent, and some have both.

Kettle — This is where you boil the wort, of course. Some kettles are quite fancy, with built in thermometers and glass water gauges, and some are quite simple. Here’s a 20 gallon boilermaker brewpot.

Greg Krehbiel's Beginner's Guide to All-Grain Brewing

If you’re feeling intimidated, don’t worry. You don’t have to do all this stuff to try all-grain brewing. In fact, I often wonder if it’s worth the trouble. I have a very simple system and don’t fuss with half the things these guys try to manage, and my beer comes out pretty well. If you want to read about the basics of all-grain brewing, try my Beginner’s Guide to All-Grain Brewing. It will take the intimidation out of the process.

You don’t have to create a micro-industrial process in your garage to brew beer at home. Still, this stuff is pretty interesting, and if you’re going to have a hobby anyway ….

Systems like the one I’ve diagrammed here rely on a series of hoses and a pump to move liquids from place to place. There are gravity fed systems that use a stand like this one, that don’t require a pump, but for this post I’m going to focus on systems that use a pump.

All the “ins” and “outs” in my diagram need to be connected with appropriate tubing. Silicon tubing is best. The connections are diagrammed above, but I’ll explain them as I walk through the process.

Starting from the beginning, you’ll fill the hot liquor tun with your strike water and heat it to the appropriate temperature. (Just pour the water in the top. The “in” on the hot liquor tun — #1 — is for the recirculating coil, not for the strike water.) The water comes out of the hot liquor tun through #3 above (yellow). That spigot is connected via tubing to #3 on the in (left) side of the pump. #4 on the right (out) side of the pump is connected to the #4 (green) on the mash tun.

Note that extra little diagram involving #2. There are two lines that need to go in to #4. One from the pump and one from #2.

Those gray lines in my diagram on each side of the pump are valves. You start with all the valves closed. To transfer the hot water to the mash tun you’ll open valve 3 and valve 4. (Note that homebrew pumps often need to be primed, so it’s possible you’ll need an exhaust option on the right side of the pump.) Once you’ve transferred the strike water to the mash tun you close those valves.

As I mentioned, some brewers like to circulate the wort through the grains in the mash tun, and through a coil in the hot liquor tun. You can adjust the temperature of your mash by changing the temperature of the water in the hot liquor tun.

To recirculate the wort in the mash, you have to add more water to the hot liquor tun and bring it up to the right temperature. Then you let the wort out of #5 (blue) to #5 on the pump, then out of #1 on the right (out) side of the pump to #1 (grey) at the “in” side of the coil in the hot liquor tun. A hose then runs from #2 (red) to #4 (green) to make a continuous flow. (Note again that little diagram involving #2 and #4. You’ll need to adjust that valve to get the flow from #2 to #4.)

To transfer wort to the brew kettle you connect #5 (blue) through the pump to #6 (pink).

To cool the wort you connect #7 (light purple) through the pump to #8 (dark red), then from #9 (brown) to your fermenter.

I’ve been through this diagram a couple times and I’m pretty sure it all works, but look it over yourself and see what you think. If you see any problems, let me know.

Again, this is all very cool, and I’m half-tempted to create a rig like this myself, but — as one of my fellow brewers reminded me on Saturday — you can make excellent all-grain beer on your kitchen stove with a Papazian-style “zapap” lauter tun. There’s no need to make it complicated. But if the bug bites, I hope this diagram and explanation helps.

“Takes the intimidation out of homebrewing”

Greg Krehbiel's beginner's guide to home brewing

If you’re just getting started with homebrewing, or curious about it, please check out my introductory guide, available on the kindle for just $0.99, or in a (very short) paperback edition.

Reviewers say it teaches the lingo and the basics without getting bogged down in details.

If you’re interested in advanced brewing, please try my recently published Beginner’s Guide to All-Grain Brewing, also $0.99 on the Kindle.

Calculating the volume of first runnings

“First runnings” are the first liquids to drain out of your mash tun when you’re doing an all-grain batch. The first runnings have the most sugar. Subsequent sparging extracts less and less sugar from the grain. I suppose it’s analogous to using a tea bag a second time.

The first runnings are tempting because they are so thick and rich. Sometimes you want to make a really strong beer just out of the first runnings! But that’s not the only temptation. A buddy of mine and I have tried “hot scotchies” on brew day. You mix some of your first runnings with scotch. It’s a particularly nice treat on a cold brew day because the first runnings are pleasantly warm.

My buddy decided to make a batch exclusively for hot scotchies. He wrote as follows.

I am making a batch of wort just for drinking on brew day. I am shooting for 1 gallon of first runnings. How’s this look? 4.5 lbs of grain, 6.75 quarts of water.

That means he’s going to mash 4.5 lbs of grain with 6.75 quarts of water. The question is how much of that 6.75 quarts will come out with the first runnings — because the grain will absorb some of the water.

His ratios assume a grain absorption of about 0.15 gallons per pound. I.e., 4.5 lbs x 0.15 gallons per pound = 0.675 gallons, which is 2.7 quarts. So he should get just a touch over a gallon of first runnings.

This page says “Average grain absorption is 0.15 gallons per pound. It can vary between 0.1 to 0.2.”

But this page says you should assume 0.2.

This page has a more complicated equation that includes liquid remaining in the bottom of the mash tun and in the lines or pump. My friend doesn’t use a pump, but there’s always the chance of some liquid will stay in the mash tun — below the level of the spigot.

I suspect that absorption also varies by the type of grain and by how well it’s milled, so I don’t think it’s possible to get the figure exactly right without some experimentation. Everybody’s system will differ a little.

My recommendation was to go with a little more water.

Also, it’s a shame to leave that extra sugar on the grains. He could sparge a couple times and use that for a mild.

Trying kombucha — and what the heck is a scoby?

Kombucha is a kind of fizzy, slightly fermented, sour tea. It’s supposed to have “probiotics” and all that other healthy stuff, but I don’t pay much attention to that. When I’m sick I go to the doctor.

I like making stuff and I wanted to try my hand at kombucha. First, because it’s crazy expensive in the store, second, because I don’t drink soda (and shouldn’t be drinking beer all the time), and third because … I just like doing that sort of thing. At least once.


My daughter bought me a copy of Emma Christensen’s True Brews, which is a good book to have around the house in case you want to try making anything weird like sake or kephir or … kombucha.

To make kombucha you need a scoby, which is a symbiotic culture of bacteria and yeast. That thing on the plate is the scoby I grew. Essentially it’s a big, gross, slippery fungusy thing that grows in your tea. If that’s over the top for you, don’t try kombucha.

You can buy a scoby from a store, or online, but of course I wanted to grow my own, so I bought a bottle of kombucha from the health food store and used that as a starter. It worked, but it took way longer than I expected. More than two months.

My plan is to make a couple batches of kombucha, but then I’m going to experiment. What would happen, for example, if you used a scoby to ferment a wort?

If you want to learn more about making kombucha at home, here’s a good page.

One thing for you homebrewers to note. The instructions say to use paper towels or cheese cloth to cover the fermenter. “Ah, so primitive,” I thought. I figured I’d improve things by using a fermentation lock.

That was a mistake. You actually need the air flow to make this work. The paper towels (or cheese cloth) are there to keep bugs and dust and cats and things out of your kombucha, but you need the wild bacteria and yeast that’s floating around your house.