Olde Main's Brewing Process - The Mighty Fist of Brewing
The four main ingredients, “that are the fingers on the mighty fist of brewing” are barley malt, water, hops, and yeast. According to the German purity law called the Reinheitsgebot these are the only four ingredients allowed in beer. While we at the OMBC do adhere to this law, certain beers, like our Dinkey, call for other flavoring agents to achieve their signature taste. The “thumb” that allows the mighty fist of brewing to grip the war hammer of beerdom is the brewer.
Malt – where is pointer?
Barley is a cereal grain like oats, rice, wheat, sorghum, and corn. Barley must be malted in order to be used in the brewing process. To make malt one must soak the grain in water and allow it to start to germinate. This process is call steeping. Water is taken up by the kernels and the plant begins to grow. Starch conversion also begins during this stage, although on a very small scale. Then the kernel is kilned to stop the germination. Kilning is the drying of the malt kernels. The length of time that the kernels are kilned determines the final color of the malt. The germination process is very important to the brewer because this is when the enzymes used in the brewing process are formed.
Water – naughty, naughty tall man
Water is extremely important in the brewing process. The brewing process uses, on average, 6.5 volumes of water to make one volume of beer. There are three types of water: Product, Process, and Service. Product water is the water used in the actual beverage. Approximately 92% of beer is water. Process water is cleaning and sanitization water for all tanks, brewing vessels, hoses, and product lines. Service water is used primarily with systems using steam as a heat transfer medium. Steam acts to heat the kettle and is used to transfer heat throughout some breweries. At the OMBC, we use a direct-fire, 400,000 btu burner to heat the kettle.
Hops – ye olde ring finger
With the advent of civilization (which, incidentally, many scholars believe was directly tied to the creation of some of the first beers) many things were added to beer in an attempt to enhance the flavor and preserve the final product. This was a terrifying and experimental time for beer – without careful management of the beer additives, things could get wonky. People added all sorts of things including common table salt, iron, strychnine (not for long), various fruits, and herbs. Hops were chosen for a number of reasons. They are thought to have an antimicrobial effect that helps preserve the beer. This coincides with ethanol produced in the brewing process to keep the final product free from contamination. Hops are added directly into the kettle and the heat extracts a unique bitterness and certain aromatic agents that enhance the palatability of the beer (i.e. the “nummers” factor). Bitterness and aroma depend of the variety of the hops. They are grown in all parts of the world because the world wants beer!
Yeast – pinky, the mightiest of all fingers
Early beer was made as far back as 5000 B.C. in Egypt. It is only a relatively recent discovery that yeast is a vital component in making beer. Yeast converts simple sugars into ethanol and carbon dioxide in the absence of oxygen in a process called fermentation. Brewing yeasts are labeled into three categories: Ale, Lager, and Weizen (wheat) yeasts. This will be discussed in more detail under fermentation in the brewing process.
Brewing Beer: The right way, the wrong way, and the Olde Main way.
Milling consists of crushing the grains, but not into wee little bits. They are basically smooshed in half to expose the sugars inside. We use a Roskamp two-roll mill made right here in Waterloo, Iowa. We dump, by hand, anywhere between 1000 and 1500 pounds of grain into the mill 50 pounds at a time. The idea is to break the grain in half and leave the husk (outer covering) intact. The husk acts like a filter later in the process. The malt is now called grist.
After milling, the grist falls into a hopper where our friend, Mr. Auger, transports it up into a magical vessel called the mash tun. This is a time consuming process due to the large batch sizes and relative compactness of our auger. Weep not for us, for we make the beer…
Mash Tun – the magical homeland of worty num-nums
Grist is combined in the mash tun with hot water from the hot liquor tank and then that mix is called “the mash.” This mixture looks and feels like oatmeal. (Sidenote: in brewing terminology, liquor is just another name for water. We don’t keep 500 gallons of hot vodka handy… not all the time, anyway.) Here the mash sits at an ideal temperature of 150°F. This is when the enzymes from malting come alive and convert complex carbohydrates into simple sugars. The majority of these sugars are maltose. The mash tun has a false floor (basically a grating) at the bottom. This allows us to remove the sugar solution while keeping the husks and grain in the mash tun. This is also where the husks act as a filter. After an hour, we remove the sugar solution, now called wort (say it with me, WERT) and pump it into the kettle. The spent grain (now weighing well over 1000 pounds) is then hand-shoveled into a cart and donated to Iowa State University to feed research cattle.
Hot Liquor Tank
This big ol’ tank holds hot water that was heated in the kettle overnight prior to the brew day It holds 21.5 bbls (1 barrel = 31 gallons)of water when full (more when we overflow it to create our signature waterfall effect) and is also hard to climb out of once inside.
Wort enters the kettle at about 155°F. We fire up the burner and start the clock when it reaches 212°F. Typically, our recipes require a boil of one hour, though many other varieties of beer need longer boils to properly concentrate the fermentable sugars. Once the boil begins, hops, flavoring agents, and fining agents are added at different times during the boil. Early hop additions contribute to the final bitterness, while later additions add more aromatic qualities.
When the boil is finished, the hopped wort is pumped through a loop to create a powerful vortex of doom, capable of dragging unwary sailors down into the murky depths of this hoppy quagmire. No, seriously, we create a whirlpool to force vegetative matter from hops, coagulated proteins, and any loose botanicals to the center and bottom of the kettle… of doom. This forms, in very technical brewing jargon, “the trub” or, as we refer to it, dookie mountain. Gathering all this particulate matter allows us to pump the wort from the kettle and leave the ickyness behind. The whirlpool lasts for roughly 30 minutes. We typically use this time for having a quick pint or the occasional game of “Would You Today?”
Heat exchanger/ Cold Liquor Tank
The wort must now be cooled. This is done to prevent the yeast from dying when it is added to the wort. It is brought from boiling (212ºF) to about 65ºF. Cold water is pumped through the heat exchanger on one side whilst the hopped wort is pumped through the heat exchanger in the opposite direction. The two liquids never touch, but there is a tremendous heat transfer from the wort to the cold water. This allows the wort to enter the fermenter at a safe temperature for yeast.
Yeast is “pitched” into the cooled wort and then pumped into a fermenter. Ale yeast traditionally ferments at ~62ºF. Ale yeast also floats to the surface after the sugars in the wort have been used up. Lager yeast sinks to the bottom when the sugar supply is exhausted and ferments at colder temperatures ~50ºF. This is the main difference between the two types of beer. Ale and Lager represent two huge families. Color is not a determination between ale or lager – the process is. Fermentation at colder temperatures takes longer to complete. . A lager takes 4-6 weeks to finish and age. Ales take about two weeks to finish.
Filter and Carbonation
From the fermenter some beers will go through a filter. Not all beer is filtered. The wheat beer is not filtered… so there. This helps to clarify the product. All our beer passes through a pinpoint carbonator to help polish the carbonation in the finished product. Rule of “thumb”: 2.5 volumes of carbon dioxide per volume of beer, more or less as style dictates. Also, it is important to drink the beer that spills out of the filter during processing. This can be as much as 5 or 10 gallons, so get to it, Sally.
Ageing and Conditioning
After carbonation, the beer is stored in a serving vessel. Ageing depends on the product and the type of beer.
Bottle, Keg, or at the Pub
The beer travels directly from the serving vessels to the either the taps at the pub, a keg, or reaches the bottling line. Then it finally reaches your own “Beer Enthusiast Union” mug, and ultimately, your gullet. From there, the journey of this delicious libation is entirely in your hands… or maybe a little bit lower.