lt is the heart and soul of beer. Period. So grab a beer, and let’s talk about it.

Other homebrewers and pro brewers might contend that yeast makes beer, and they would be right. Yeast makes beer what it is, but only based on the raw materials present. For example, let’s say you have a pile of very expensive hardwood. An artist or craftsman could take pieces of wood out of the pile and make a violin or carve a beautiful sculpture. I, on the other hand, could probably only make a campfire…that is, if I also had enough gasoline. The point is that the basic building blocks (malt) are the same and the artist and arsonist (Yeast) both make something different from it.

Treatment of malt in both the homebrew and commercial brewery are very similar. The grain comes out of the bag intact and must be “crushed” to expose the inside of the grain to the mash (“strike”) water. When exposed to water in the 144-160⁰F range, enzymes present in the malt begin to convert starch to sugars that can be consumed by our artist friend, Yeast. However, for this homebrewer, the scale of malt, how it is milled, how it’s moved to the mash tun (where it is steeped in that hot water) and how it is hydrated in a commercial brewery was an eye-opener.   

Freshly ground grain goes into the sieves

First of all, the milling process was much, much bigger. On the homebrew level, most grain mills are either powered by a hand crank or turned with a 3/8 – 1/2” electric drill. Even at a relatively small brewery like the one where I am volunteering, a giant AC motor turns the mill. At the homebrew level, a big beer (think Russian Imperial Stout or Barley Wine) might use 16-20 pounds of grain for a five-gallon batch. On the commercial level of seven barrels (about 217 gallons) even a relatively small ABV beer uses 375-400 pounds of grain.

To start the milling process, we do a crush test on about 6-8 pounds of grain to see if the mill is performing the way it should. The test grain is captured in a bin and a portion removed and weighed. Once we weigh it, we put the grain in a giant, five-layer, multi-screen sieve, where it’s mechanically – and violently – shaken for a minute or two. We take the sieve apart and weigh the contents of each layer of the sieve, with particular interest in the “course grit” and “fine grit” layers. If these two comprise at least 80% of the total weight, the mill is working properly and we are ready to brew.

Grain awaiting the mill

Next step: start the mill and start the auger. Just like at the homebrew level, the mill is inertia-driven and needs to be moving before you start adding grain. Once we start adding grain to the mill hopper, we can never let it run empty, because the auger is dropping the grain through the hydrator while the hydrator is mixing very hot water (about 10⁰F above the desired mash temperature) with the milled grain. If the grain stops, the mash gets hotter than we want it. Sounds easy enough, but the grain bags weigh 50-55 pounds and the hopper only holds about 25-30 pounds of grain, which means you have no time to open another bag. They must all be prepared and staged right next to the mill ahead of time.

The hydrator where milled grain and hot water meet

Something I did not expect about milling and mashing at the commercial level was the strict order to putting grain through the mill. Base malts (80% or more of the total malt bill) go in first and last, with the specialty malts (those to add colors, flavors or character) in the middle. This ensures that base malts are the last malt to pass through the auger, so as not to throw off the next crush test.

While one person puts bag after bag of malt through the mill, the brewer controls the water going into the hydrator, to maintain the desired temperature, while also continuously stirring the mash. Although this doesn’t sound too labor intensive, I assure you it is something to watch. No one who mashes in a mash tun that is not automated (a motor driven mash “rake”) is without blisters and calluses.

The spent grain

Once the mashing is complete, we begin the vorlauf process – recirculating the newly created sugary water (wort) through the mash to further clarify the wort. Since the husks and grain bed make an excellent filter, this part doesn’t take very long. Once the vorlauf is complete, we move the wort to the boil kettle while simultaneously adding hot water from the hot liquor tank (sadly, there is no liquor in the hot liquor tank) to the top of the mash tun to rinse out all of the useable sugar out so that it can be converted to alcohol. When the mash tun is empty, we remove the now “spent grain,” which is then responsibly recycled either into livestock feed or burger and slider rolls for the brewpub. 

July 16: I was carrying my water bottle, a bag with two beers from Massachusetts to drink with the brewers at the end of the day and all the excitement of a kid the night before Christmas. The 10-minute walk from my apartment to the brewery felt like a year.

I arrived five minutes early to find Head Brewer Eric already deep into the day’s tasks. Apprentice Brewer Matt started showing me the ropes immediately, and within 10 minutes, even in the cool morning breeze at 7 a.m., I could feel my brand new brewery hat becoming wet with sweat.

So what do you do on your first day as a volunteer at a brewpub in the tropics? Just about everything.

• First, open up the bar and brewery sliding doors, put out all the chairs and unlock everything for the day.
• Learn how to use a tri-clamp…and how hard it is…and what it sounds like when you drop it.
• Start the caustic cleaning cycle in the fermenter that previously contained the jalapeno beer.
• Repeat said caustic cycle, because the fermenter stills smells like jalapenos. (Note to self: chili pepper oils tend to stick around, so use a designated fermenter).
• Hot-water rinse the fermenter.
• Sanitize the fermenter, three times.
• Build the keg-filling rigs and the yeast rigs.
• Move kegs, fill kegs, deliver keg (that’s right – I delivered a keg to a bar around the corner – after all, I did say I wanted to learn everything).
• Get grain (50 or 55 lb bags), mill grain, learn how to open and how not to open up a grain bag.
• Clean out mashtun, putting the spent grains in giant rolling trashcans for the local farmers to pick up. Nothing gets wasted, the spent grains are either fed to livestock or made into slider buns by a local bakery.
• Eat…and realize that I am beginning to get really sore (already, or just, five hours in to the workday).
• Measure out hops additions…twice, because someone spilled some (someone other than me, thankfully).
• Squeegee everything, always keeping the water moving toward the drain.
• “Pack the heat exchanger with caustic” fresh water rinse, sanitize the heat exchanger before transferring beer to the fermenter.
• Polish three 7-barrel fermenters. Yep, that sucked, but – like a good field day in the Navy –  it has to be done.
• Split a ½ barrel (15 gallons) into three 1/6 barrels (obviously 5 gallons each)
• Move hoses and pumps (all day).
• Clean the grain mill – twice, because I didn’t do it right the first time.
• Learn that a 7-barrel pitch of Cal Ale costs almost $300, which is why they go five generations with yeast harvested from the fermenters.
• Clean up after the boil process while transferring the hot wort through the sanitized heat exchanger (boil temp to 70F) and then into the fermenter. (This step is called “knock out”)
• Get sent home 90 minutes early, because the professionals are pretty sure they almost killed the “volunteer” on his first day.
• Shower and go back for beers.
• Revel in surviving the first day

At the end of that first day I had some pretty big takeaways.

1. Standing on concrete all day is hard on your body, and ridiculously hard on mine. Take Aleve before starting the work day and wear good work boots.
2. Working in a brewery is hot, damp work. If you are not completely soaked with sweat, you will be with brewery water. Make sure you have good, waterproof work boots.
3. Even after having my ass kicked all day, you couldn’t tell by the smile on my face. The adrenaline thrill can pretty much get you through anything.

Over our next beer, we will discuss all things grain.