Plants and People Beer-making
Beer is proof that God loves us and wants us to be happy---Benjamin Franklin.
FERMENTATION Sugar Carbon dioxide + ethanol
Ales • Brewed with "top-fermenting" yeasts at temperatures from 10-20 ° Celsius. • Ales include bitters, pale ales, porters, stouts, and barley “wines”
Lagers • Brewed with "bottom-fermenting" yeasts at colder temperatures of 2-10 ° Celsius for a longer period of time than ales. • Lagers include Czech-style beers, bocks, doppelbocks, Munich, Vienna, Märzen, and pilsner beers, as well as malt liquor.
Hops Humulus lupulus Bracts from the female inflorescence
Yeast Saccharomyces cerevisiae A unicellular fungus that reproduces by budding.
Malting Malting is the soaking and sprouting of the grains. Grains that are “active” contain the enzymes that will break down the proteins and starches in the grain. The resulting sugars are what will be fermented by the yeast. Grains are dried after malting. An amylase protein molecule
Mashing Mashing turns the starches in grains into sugars. Enzymes present in the grains themselves do much of the work. Malted grains are heated in water, and at the end of the process, the temperature is raised to deactivate the enzymes. The resulting sweet liquid is called WORT.
Sparging Sparging involves rinsing the grains in the mash to obtain all of the sugars.
Boiling/Hopping Boiling concentrates the sugars in the wort and kills any bacteria that might affect the flavor of the beer. At this stage the hops are added. Boiling releases the aromatics in the hops.
Cool down The concentrated wort must be cooled to a temperature that is safe for the yeast. The boiled wort is strained into a clean brewpot and chilled to 15.5°C (~60°F.)
After this point, everything that touches the wort must be sterile or sanitized!
A HYDROMETER is used to measure specific gravity, which indicates the percentage of sugar in the wort. This figure can be converted into an indication of the percentage of alcohol in the finished beer.
Yeast is added to the cooled wort, which is poured into a sanitized fermenter.
Fermenting During fermentation, yeast convert the sugars in the wort into alcohol. Carbon dioxide is released. There must be a way for the carbon dioxide to escape, so we will be using an airlock.
Racking and Bottling Racking draws the beer off the yeast. The beer is then bottled. Depending upon the type of beer, additional fermentation may be encouraged in the bottle.
Siphoning beer away from the yeast into the bottling bucket. The beer is next siphoned into bottles.