Editor's note: this post was written by our summer intern/Sour Guru, Mike Tonsmeire, AKA The Mad Fermentationist and cross-posted to his eponymous blog.
Three years ago I (Mike) did a post on my basic homebrewing process. Since then it has been of the most popular pages on my blog. Several people have told me that it really helped them to see an example of a complete process, rather than reading a book that can be overwhelming with several options for each step. In a similar vein, I thought I'd walk you through a brew day at Modern Times. This won't be enough specificity for you to brew a batch on our Premier Stainless Systems 30 bbl brewhouse, but hopefully it is enough to give you a flavor of what a batch on a three vessel craft system is like.
This particular batch was the third of Lomaland saison. Alex "Captain Kunindra" Tweet walked me through the first half of the brew, before our head brewer Matt Walsh arrived to finish things up. Ironically Alex's first all grain batch a few years ago was a recipe posted on my blog (shortly before he swept the Ballast Point competition that earned him his nickname). Matt has been a brewer for years, starting at Alesmith before stints as head brewer at Karl Strauss, Speakeasy, and most recently Lost Coast. Excuse the photo quality, I brought along my DSLR, but left the memory card in my computer. As a result I had to shoot with my phone.
This big red box is our hot liquor tank (HLT). Purchased secondhand, it is automatically controlled to keep a supply of hot water ready to use for the mash, sparge, and cleaning.
Here is the control board for the mash tun, there is a similar one for the boil kettle, and another for the fermentors. At the moment nothing has been switched on.
Here is the mash tun. The "rakes" on the right side are raised or lowered manually. They stir the mash, and are used to clean out the mash tun. Running the rakes down with the mash tun full of spent grain can cause serious damage.
Unlike homebrewing where the mash water is heated in its entirety to a specific temperature, here the water from the HLT is cut with cold water (via the black-handled valve) to reach the desired temperature as indicated by the thermometer at the top.
To get hot water to the brewhouse we hit the HLT to Brewhouse button. This stops additional water from being added to the HLT or heating.
The clean in place (CIP) is opened so that the hot water is sprayed over the interior of the mash tun to pre-heat it to the target mash temperature.
The valves below the mash tun are opened to allow this pre-heating water to drain. The door used to empty the spent grain is also cracked to allow the hot water to drain.
Here you can see the hot water spray on the manway of the mash tun.
The temperature slowly rises over about 15 minutes.
The hot water drains.
Alex closes the valves, to be trapping water in the mash tun.
About 100 gallons of water is allowed to enter the mash tun without any grain. This lays a foundation so that grain is not forced down onto the false bottom that serves to separate husks from wort during lautering.
Alex continues to dial in the temperature to reach the target, about 11 F above the mash temperature (149 F).
Our flow rate (gallons per minute).
Right on target (after a minute or two of fiddling).
The rakes are turned on to stir the mash.
Once the temperature is on target, and the foundation water has been laid, the auger is switched on to deliver the crushed grain.
The door is slid out to allow the grain to mix with the hot water as it enters the mash tun.
Alex fiddled with the cold water to get the temperature just right as is seemed to be coming in a degree or two high.
When the grain is almost drained from the hopper, Alex ground a final bag of pale malt to ensure all of the specialty malts were "chased" out. This is especially important when brewing a darker beer, as it doesn't take much dark malt trapped in an auger to affect the color and flavor of the following beer.
Crushed grain passing out of the storage hopper and into the auger that carries it to the mash tun.
The mash tun as it fills with hot water and grain.
When all of the grain is in the mash tun, we continue to run the water until we hit the target volume.
The hop extract used for bittering is put onto the boil kettle in advance so it warm up and liquefies (it is very thick and syrupy right out of the cold box).
More valves are manipulated to allow wort to be pumped from the grant back into the top of the mash tun, preparing to vorlauf.
After the 20 minute mash rest, here is what the wort looks like.
The mash tun has two sight glasses to allow us to gauge how the wort is flowing through the grain bed. The one on the left shows the pressure above the plates, and the one on the right is below (it would much easier to see with a stout). If the one on the right is just a few inches below the one on the left, then things are running smoothly. In the difference is greater, then the wort isn't flowing well and you may be in for a stuck vorlauf/sparge.
The valves and pump speed are adjusted so that the wort flows into the grant at the same rate it is pumped out. This is the easiest time to get the flows equal so it does not need to be adjusted later.
After 20 minutes of vorlaufing the wort is flowing much clearer.
Here is the empty boil kettle. The hole at the bottom is for cleaning, wort headed to the chiller will exit the hole at 1 o'clock.
He takes the gravity of the first runnings.
Our final mash temp is only .4 F below our target. It is easy to over-correct. Initially the temperature appeared low, then high. Trusting the water temperature calculations are key, any adjustments need to be slow and subtle.
As enough wort flows into the boil kettle to cover the bottom we turn on the kettle's bottom steam jacket. Unlike many smaller breweries (and 99.99% of homebrewers), steam from a boiler heats the kettle rather than a direct flame or electric element
When the wort drops to level of the grain bed, we begin to sparge with 170 F water. The goal is the keep the sparge water flowing at a rate the keeps it just an inch or so above the grain bed.
As the sparge continues, and the kettle fills, we turn on the other jackets to speed the heating.
When the sparge is complete (signaled not by volume, but by the runnings reaching 2P, 1.008), the spent grain is allowed to drain. When it is reasonably dry, a hopper is positioned under the door.
The door is opened and the spent grain is allowed to spill out (and then encouraged to do so with the rakes).
Once the wort reaches a rolling boil we pull a sample to test the gravity.
We were slightly under volume, but over-gravity, so we added one barrel of hot water. Then a few pumps of foam control followed by 30 IBUs of hop extract (the tins are rinsed to get every drop of extract out).
With 20 minutes left in the boil yeast nutrient and Whirlfloc are added.
A solid rolling boil.
After 60 minutes the steam jackets are turned off and 22 lbs of Saaz hop pellets are added.
There is no hanging out while we're brewing, any downtime (mash rest, sparge, boil etc.) are taken up by other chores like kegging.
After a five minute whirlpool and 20 minutes of settling, the wort is still at 210 F. This is the reason we were getting significantly more bitterness from our recipes on the big system than we ever did in test batches.
The valves are moved, and the connections are made to send wort to the sanitized fermentor.
With the wort ready to run off the oxygen in turned on to be shot into the wort in-line after chilling.
The water from the cold liquor tank (which is chilled to around 40 F) is running full blast to the plate chiller, so the pump speed for the wort is adjusted to achieve the target pitching temperature of 75F.
The oxygenated wort flowing through a sight-glass.
A sample of the wort, just a few tenths above our target OG of 12P.
With the fermentor filled, the line is pasteurized with water from the HLT (which was mostly refilled with "waste" water sent there from the heat exchanger) to prepare it to pitch the yeast.
The 100 L of yeast slurry harvested from Lomaland batch #2 is forced into the fermentor using CO2 pressure.
The now empty 100 L keg is then flushed with hot water to remove any residue.
A local farmer arrived to pick up the spent grain for animal feed.
The fermentor control board, showing we are a single degree under our target for fermentor #3.