I came back to Canada and decided to visit some of my old brewing classmates to see where they were working. The first brewery I visited was Monkey 9 Brewing, a brewpub located in Richmond, BC. My friend and brewing classmate from the KPU brewing program, Xander Szymanski, was brewing Dad’s lager beer. This lager beer has the flavour profile of a classic German-style lager. It is crisp and clean with a mix of floral hops. So let’s get into their brewing process!
Xander’s brew day began at 8:30 am. The first thing he did was turn the boiler on so that it could get up to 10 psi of pressure. He needed to get the boiler working so that he could heat up the water for his brew day, and also so he could turn on the steam jackets on his mash tun.
1. Milling
Grain milling began at 9 am and took around 20 minutes to complete. Xander used 9 bags of malt in total. These malts included: Pilsner, Vienna, and Carapilsner malts. Xander had to manually bring all the bags of malt up to the second platform where the mill was located. As you can imagine, this was quite a taxing job.
He then lifted each bag of malt up and poured it into the mill. Xander visually checked the grind of the malt by making sure it was not too fine and powdery. He also made sure that the malt kernels were split and the endosperm was exposed. The milled grain moved through an auger conveyor, which is basically a rotating screw blade within the tube that moves the grain forward.
Once the milling was complete, the milled grain sat above the mash tun in a grist hopper. A hopper is a container for a bulk material such as grain, rock, or trash, typically one that tapers downward and is able to discharge its contents at the bottom.
2. Mashing In
To start the mash, Xander first moved 110L of hot liquor from the kettle to the mash tun. Hot liquor is just a fancy brewing term for hot water. Hot liquor refers specifically to water used for beer production. That means that water used for cleaning and other purposes in the brewery is just called water. The 110L of hot liquor in the mash tun serves as foundation water, so that we aren’t adding grist into an empty mash tun. Grist refers to malt and cereal that is ground (milled) in the brewhouse by a malt mill at the beginning of the brewing process.
When the flow meter read 110L, Xander opened the slide gate of the grist hopper. Beside the grist hopper is a grist hydrator. Hot liquor flowed through the hydrator and mixed with the grist. This ensured that the grist was thoroughly rehydrated. We don’t want any dry lumps of grain going into the mash tun.
Mash Strike Temperature
Xander adjusted the slide gate opening to find the optimum water to grist ratio so that he was not mashing in too dry or too wet. He visually looked for a “lava-like” flow while mashing in. The strike temperature he looked for during mashing in was 62°C. Strike temperature refers to the temperature of the hot liquor (hot brewing water) used to create the mash.
Before hot liquor reaches the grist hydrator it first goes through a temperature gauge. Xander adjusted the flow of cold water from the tap water pipe until the overall temperature was 62°C. Mashing in took 20-30 minutes, and 875L water was used (including the foundation water). Ideally, we would like to run out of grain before we run out of water during the mashing in stage since we don’t want to have the dry grain going in on top.
Once mashing in was complete, Xander mixed the mash with the mash tun rakes to ensure the grain was well mixed. The temperature of the mash was 65°C this time. Xander would like it to be 68°C, so he turned the steam jackets on to bring up the temperature of the mash.
3. Saccharification Rest
A 45 minute saccharification rest followed to allow the enzymes in the grain to convert the starches into fermentable sugars. While he was waiting for the enzymes to do their magic, Xander took off the grist hydrator and cleaned it.
4. Mashing Out
After 45 minutes, the temperature in the mash tun was between 75-77°C. Raising the temperature that high denatures all the enzymes in the mash. This means that all enzyme activity stops and there is no more conversion of starches into fermentable sugars. To raise the temperature Xander turned the steam jacket on. The steam jacket can only be turned on and off and cannot be set to a certain temperature. Thus, Xander had to constantly mix the mash to make sure the temperature in the middle and the sides was even. It took 15 minutes to reach the mash out temp of 75°C. Before he reached the desired mash out temp, he turned the steam jacket off as the residual heat left in the steam jacket continued to raise the temperature.
5. Vorlauf
Xander vorlaufede to ensure the wort collected was clear. Vorlauf is a recirculation process where the wort collected on the bottom is recirculated back on top of the mash until it runs clear. Vorlaufing allows coarse grain to move back to the top of the mash bed, so that only clear wort goes into the kettle. The vorlauf took around 20 minutes for this brew.
During the mash out stage, Xander set up a grant.
A grant acts as an intermediary vessel. If the wort from the bottom is directly drained out the bottom of the mashtun and recirculated back to the top of the mashtun, it may cause the grain bed to be sucked down. A disturbed grainbed equals poor run-off and a potentially lower original gravity (OG) which is why the grant is important as an intermediary vessel.
OG is a measure of the solids content originally in the wort, before fermentation has started to produce the beer. OG is one of the major measurements used to determine the future alcohol content of a beer fermented from a particular wort.
6. Sparging
After the vorlauf, wort collection began in the kettle. Xander began sparging when he saw that there was only an inch of liquid above the grain bed (Sparging is when we spray fresh hot liquor onto the mash to rinse out any residual sugars from the grain).
Xander sparged until it read 600L on the flow meter. He collected 1200L in the kettle, which is full capacity. The sparge took 45 minutes and the temperature of the hot liquor was 78°C.
7. The Run-Off
When the kettle sightglass read 150L, Xander opened the bottom steam jacket on the kettle to start heating the wort. When the kettle had 600L, the side steam jacket was also opened.
The duration of the run-off into the kettle was approximately 90 minutes. Then Xander checked the specific gravity in the kettle. The specific gravity (SG) refers to the ratio of the density of a substance to the density of a standard, usually water for a liquid or solid. The density of wort is largely dependent on the sugar content of the wort. A wort with more sugars in it will be more dense meaning it will have a higher OG. Since more sugars mean more alcohol, measuring specific gravity is important to predicting the beer’s final alcohol percentage. Today, we had an SG of 1.080 and our target SG was 1.070.
Xander also measured the first and last runnings of our wort collection into the kettle with a refractometer. First runnings refer to the heavy wort extracted from the mash at the start of the run-off into the kettle. Last runnings refers to the wort extracted from the mash at the end of the run-off from the mash tun to the kettle.
8. Draffing Out
While waiting for the wort to come to a boil, the spent grain was loaded into compost bins and taken out back. A local farmer regularly comes and picks it up.
9. The Boil
We expected 100L of wort to boil off during the 90 minute boil. Xander measured out his 3 hop varieties: Apollo, Hallertau, and Spalter Select. After 30 minutes of boiling, Xander added Apollo hops for bitterness. Then after 75min of boiling, he added in two of his flavouring hops. After 85 minute of boiling, he added in his last flavouring hop addition. I should also mention that fermcap, an antifoam agent, and whirlfloc, a clarifying agent were also added during the boil.
10. Whirlpool
When the 90 minute boil ended, Xander started the whirlpool which lasted for 25 minutes. The first 15 minutes were with the pump on, and the other 10 minutes were with the pump off. Whirlpool is when we create a circular current in the kettle. The motion is meant to help separate the trub from the wort after the boil. Trub is the term used for the material, along with hop debris, left in the whirlpool or hopback after the wort has been boiled
11. Fermenter Cleaning
After the whirlpool stage, wort is transferred to the sanitised fermenter.
I want to touch on how the fermenter was cleaned. The fermenter was CIP’d with 3% NaOH for 20-40min. The duration of the cleaning time depends on the temperature of the caustic solution. If it is warmer then the duration will be lower, and if the temperature of the cleaning solution is lower then the duration will be higher. After this caustic clean the fermenter was rinsed with water until a neutral pH was reached. Unfortunately at Monkey 9, they only use their caustic once and dispose of it. At some breweries they have CIP tanks where they can reuse the caustic a few times before getting rid of it.
Once rinsed until neutral, the fermenter was rinsed with our sanitizer, peracetic acid for 10 minutes. After 10 minutes, the fermenter was emptied and degassed. The reason it was pressurized the night before was to make sure no outside air was in it. After degassing the fermenter, a blow-off tube was attached to it. A portion of the sanitizer was emptied into a bucket and then the blow-off tube was put into that bucket full of sanitizer. In this way, the carbon dioxide gas produced from the fermenting beer has a “sanitized” environment to pass through. Although the sanitizing power of this solution is already decreased since it has been used once already.
12. Transfer Into The Fermenter
During the transfer, the wort passed through a heat exchanger which works on a glycol system. This is a specific kind of refrigeration system often used to cool a variety of liquids including alcohol and other beverages. To cool the wort to the low temp of 12°C, the transfer was done slowly and took over 30 minutes to do. As wort filled up the fermenter, any air was pushed out of the fermenter and escaped through the blowoff tube.
13. Fermentation
When a couple hundred litres of wort was collected in the fermenter, Xander pitched in some packets of dried yeast.
Dad’s Lager is allowed to ferment for up to 3 weeks at around 12°C before getting conditioned for up to 5 weeks before it is canned.
Conditioning, or lagering, is a form of beer maturation where the beer is stored at a low temperature for a longer period of time. During conditioning, Dad’s Lager will undergo subtle, but significant flavour-altering biochemical processes that are responsible for the crisp and clean taste we usually associate with lager beers. Whew, that was a lot of information, glad we got through it all!
Watch it on YouTube Below
Leave a Comment