Once you have wort, its time to actually “brew” (from the Dutch brouwen: to bubble or effervesce) the beer. I hope by now you realize that a lot more work goes into preparing to brew than actually brewing the beer. When I do demonstrations, someone always remarks that brewing takes a long time but in reality, the part they see at these events is only about 10% of the total effort and time involved.
Converting the sweet sugary wort into beer involves five main actions:
- Boiling: This step is where we break down the proteins in the wort, kill any undesirable pathogens that were introduced with the water, and flavor the beer. It sounds easy, just add heat until the wort boils. The problem is that there is a lot of sugar and protein dissolved in this work and those substances will cause the wort to foam. Left unchecked the kettle can boil over extinguishing the fire so bringing the wort to a boil requires constant stirring. Once the wort reaches the “break” temperature, the rolling boil will reincorporate the foam into the wort and it can boil unattended until you add other materials to the brew.
- Adding Hops: When and how you add hops and other botanicals to your boiling wort will determine the level of bitterness (IBU) and the “nose” (floral esters) of your beer. Hops added early in the boil allow humulones from the hops to be extracted but the esters will evaporate so these hops add only bitterness. Hops added at the end of the boil impart a flowery scent to the beer but have a very small impact on bitterness.
- Proofing the Yeast: Before you can use your yeast, it should be “proofed” (from the Latin proba: to test). This involves getting a batch of yeast to begin to grow rapidly in a sugar water solution. Proofing your yeast ensures your yeast is viable and the beer will ferment.
- Chilling: Bringing the temperature of your wort down to a level where it does not kill the yeast was a challenge. The chilling process must be done in a manner that prevents contamination but there are relatively few effective ways to do this available to the 18th Century Brewer.
- Natural Chilling: If it is cold on your brew day, you are in luck, even better if it snows. A covered thin metal kettle of beer will chill from boiling to “blood temperature” in a snow bank at a rate of about 10 min/gallon.
- Using Running Water: Depending on the temperature of the water and how easily and fully you can immerse your kettle in the stream, placing your brew kettle in a small creek or river can be more efficient that putting it in a snow bank.
- Using the Kühl Schipp: Belgian brewers employ a shallow tray, open to the air, through which the wort is allowed to flow from boil kettle to fermentation vessel. The wort then cools through evaporative and radiative cooling. It also opens you up to contamination as airborne particles can settle into your beer.
- Wait: A covered kettle will eventually cool to “blood temperature” but this will take about 30 minutes/gallon.
- Fermentation: Once the wort is cool enough, add yeast and transfer the resulting beer into a vessel that is sealed but still allows gases resulting from the fermentation process to be released. Colonial Brewers frequently fermented their beer in wooden barrels which had been fitted with leather flaps over the bung to allow the gases to escape but preventing outside air from entering. I use large glass bottles (carboys) with water locks.
After your beer has been allowed to ferment for about a week, it is helpful to “rack” the beer from on fermenter to a fresh one. This removes the beer from the yeast that have died and fallen to the bottom of the fermenter and helps clarify your beer. It is important to slowly siphon the beer from one vessel to the next, not pour. Eventually, you will observe that your beer stops emitting gases and has completed its fermentation. At this point you can bottle or keg the beer.