Commercially malted grains are obtained at a local merchant, and cracked at the store on a roller mill. On the day of brewing, the grist is mashed according to the single infusion process.
About three gallons of water are heated to 172ºF, of which one gallon is added to the mash tun (the container for mashing, in this case an insulated water cooler) and mixed with 1½ teaspoons gypsum or Burton water salts. The addition of gypsum (or other water salts) increases the hardness of the water, which in turn increases the efficiency of the starch conversion and intensifies the bittering effect of the hops. Cracked malt is added to the hot water and stirred thoroughly, then more hot water, then more grain, etc., a process known as striking. The final desired result is a mash whose consistency is neither too dry nor too watery, with a temperature of about 148º - 155ºF.
The mash tun is sealed and the mixture incubated for between 1½ and 2 hours, stirring once about halfway through.
The same vessel acts as the mash tun and the lauter tun, and has a plastic false bottom (a commercial product of Listermann Manufacturing Co.). Towards the end of the mashing, three gallons of water are heated to 172ºF and placed in a bottling bucket (a bucket with a spigot on the bottom). The vorlaufing is performed by draining up to 2 cups of wort at a time into a glass measuring cup and pouring it back onto the mash until bits of grain pretty much stop leaving the tun. Then a rotary sprinkler (another Listermann product) is attached to the spigot of the bottling bucket and hot water sprayed on on the mash (sparging). The rate of draining is adjusted to match the rate of spraying, so that the level of liquid is visible just at the topmost grains of the mash. Finally, the sparging is halted when a little over three gallons of wort are collected.
Recently, I've revised my technique to collect an additional two quarts of wort and add it occasionally during the boil (see below) to replenish the level. Depending on the amount of grain being mashed, this can significantly increase the yield.
The wort is brought carefully to a boil (to prevent foaming and scorching) in a 3.5 gallon stainless steel pot. Once the wort reaches full boil and foam has subsided, any adjuncts are added. Once the boil is back to full, the 60 minute timing begins. Hops are added at different stages: 60 minutes (e.g. the full boil) for bittering, 30 minutes for bittering/flavoring, and 5 minutes for finishing. To improve clarity, Irish moss may be added at 10 minutes before the boil. Volatile ingredients (such as spruce extract) are added at the end of the boil.
During the course of the boil, additional wort is added to keep the level replenished. Care is exercised not to add too much at once, nor to add any past the 20-minute mark (so that all wort added will boil at least 20 minutes to precipitate any proteins).
After brewing is over, it is important to cool the wort as quickly as possible to the temperature suitable for adding yeast. Quick cooling helps prevent other organisms from gaining a foothold. The brew pot is partially immersed in a running cold water bath and the wort stirred constantly until the temperature is lowered to 75ºF - 80ºF. (The spoon, thermometer, etc. are kept sanitized with the aid of an iodophor solution—I generally use ¼ ounce iodophor in 2½ quarts warm water).
Once cooled, the wort is poured into the fermenter through a strainer to remove as much hop residue as possible. (The fermenter and the strainer are both sanitized; at this stage, all surfaces and utensils which come into contact with the wort must be sanitized to reduce the risk of contamination.) Cold water is added as needed to increase the final volume to the desired level. For example, for a three gallon batch I'll add enough water to raise the level to about 3.2 gallons to account for loss during the transfers.
The yeast (often recovered from a previous batch of beer—see Secondary Fermentation below) is pitched (added) and the mixture stirred vigorously. One cup of the mixture is set aside for a satellite fermenter: this is a small fermenter (e.g. a bottle covered with plastic wrap) used to monitor the change in specific gravity over time (an indicator of sugar consumption—as sugars are converted to alcohol, the specific gravity drops until terminal gravity is reached.).
Finally, the fermenter is sealed and fitted with an airlock to allow CO2 to escape without the entry of air. For most batches, the primary fermenter is a 5-gallon plastic bucket with a tight-fitting lid. For lagers, which require longer fermentation times, the wort and yeast are mixed in a bottling bucket and drained into a 5-gallon glass carboy for fermentation.
For ales and steam beers, fermentation takes place at room temperature (66º - 70ºF). For lagers, the yeast is allowed to start at room temperature (12-18 hours) and then transferred to colder temperatures (45º - 50ºF).
5. Secondary Fermentation
During the first stage of fermentation, the yeast engages in its most vigorous activity. After three to four days (longer for lagers), the yeast activity tapers off and the cells began to settle to the bottom of the fermenter. While the beer retains its turbidity (i.e., many yeast cells remain in suspension), it is siphoned away from the sediment (also known as racking) to a secondary fermenter. Generally, the secondary fermenter is a 3-gallon glass carboy, stoppered and fitted with an airlock.
When a 3-gallon batch reaches terminal gravity, it is siphoned into two 5-liter kegs and two 22-ounce bottles (a 2.5-gallon batch uses two kegs, a 5-gallon batch four kegs). One tablespoon of corn sugar is added to each keg, and one teaspoon to each bottle: this primes the beer so that the relatively few yeast cells remaining in solution will produce CO2 for natural carbonation, a process known as conditioning.
After as much beer is removed as possible, the yeast remaining at the bottom of the fermenter is carefully poured into a sanitized jar and refrigerated until the next batch. Yeast recovered in this way generally may be reused 4 to 5 times before genetic drift begins to affect its character noticeably.
The containers of beer are kept at room temperature for a few days, then stored at garage temperature until opened. Aging may vary from 4-16 weeks; strongly hopped beers tend to require more aging, but nearly any recipe will improve with at least 8 weeks aging.
Modern practices of sanitation, production, and containment need not and should not be avoided in the name of authenticity. True, many Medieval brewers perpetuated fermentation via yeast cells lodged in the pores and crevices of fermentation vats. Others utilized wind-borne organisms: to this day, brewers in Belgium's Payottenland region rely upon delicate and complex interrelationships between wild microflora that have evolved naturally over centuries. But in most contemporary habitats you never know what the hell's going to fly into your pot.
Indeed, the proliferation in Medieval times of "cures" for muddiness, ropiness, fustiness, and sourness in wine and beer would seem to indicate a preponderance of poor methodology. In his history of Sweden, Franklin D. Scott has this to say about life during the late Middle Ages: "The result [of heavily salted food] was both unpalatability and thirst, a thirst that could be satisfied only with quantities of beer. The ordinary Swedish beer was weak and easily soured, and only the wealthy could afford the German import."
This is not to say that the Swedes were incapable of brewing good beer. Surely there were those whose love of brewing was accompanied by a zeal for observation, experimentation, innovation, and mercantilism. During the 13th - 15th centuries, Sweden's trade economy was utterly dominated by the Hanseatic League: though the scarcity of extant recipes points to a general closeness of trade secrets (or a specific illiteracy of brewers), is it not conceivable that such an extensive network of German traders could lead to a widespread dissemination of ideas and ingredients?
Personally, although I'll brew a more "traditional" recipe now and then, some of my best recipes have come about through the impulse to throw together whatever appeals to me at the time. It's fun! And it is on both the aforementioned necessity of modern techniques and the speculation of Swedish ingenuity that I argue the validity of my approach to brewing.
1. Grains and Malting
A beer is a fermented beverage in which the sugars upon which the yeast feeds are derived from converted starches; the starch conversion distinguishes beer from wines and meads, which contain fermentable sugars at the start. Grains to be converted are soaked in water and dried just before they actually sprout, a process known as malting. At this point, starch conversion enzymes (amylases, a.k.a. diastases) are concentrated in the embryos.
Traditionally, grains are malted by spreading moist grains on a stone floor, raking them regularly, and then drying them. (Michael Jackson, in his Beer Companion, relates an observation of western Norwegian farmers steeping their grains by tying a sackful to a rock in a fast-flowing river). Grains have historically been dried by wind or in kilns.
Smoked grains: In Scandinavia, grains were often dried over an alder wood fire, imparting a smokiness; I have chosen to emulate this effect by adding German hardwood smoked malt to certain of my recipes. Scottish ales—characterized by a heavier malt and lighter hop content—traditionally do not contain smoked malts; however, I have achieved excellent results from the addition of peat smoked malt to such recipes. Nonetheless, it is notable that William Harrison, in his Description of England (1577), disparages smokiness in malts, as does Andrew Boorde in his Dyetary of Helth (1542).
Specialty grains: grains which impart colors and/or flavors are derived by variations in kilning techniques. For example, the sweetness in Crystal malt is obtained by kilning the grains while still moist, causing carmelization of sugars. Roasting malt imparts dark colors and toasty flavors. Specialized strains of barley may impart certain other characters, such as increased maltodextrin content (contributing to a heavier, silkier body and better head retention). Other grains often malted for use in beers include red wheat, white wheat, and rye.
Adjuncts: unmalted grains (such as corn or rice) may be added to the mash; if used in moderate proportion to malted grains, there will be sufficient enzymes for conversion. Commercially, corn and rice are added to make a cheaper, lighter beer. Flaked barley, rye, or oats can add body, head retention, and characteristic flavors to a brew.
Because malting and kilning is a highly specialized and intensive art, I purchase my malts from a local merchant. Although smoking malts is a relatively simple process and may be done at home in a barbecue grill, I have not attempted it at this time; I may do so, however, in a future recipe.
Due to local sanitary conditions, beer historically was recognized as a healthier beverage than water (it was boiled). Nonetheless, the character of the water used in brewing can affect the resulting beer. Personally, I am very happy with the quality of the tap water where I live (the Cheshire neighborhood of Flagstaff, which receives its water chiefly from snowmelt off the San Francisco peaks). Thus, I don't bother to purchase commercially prepared water.
The conversion of starch takes place in the mashing process. Prior to mashing, the malted grains are cracked in a mill. It is desirable for as many seeds to be cracked as possible without creating too fine a grist: too coarse, and not enough seed body may be exposed for thorough conversion; too fine, and you could get a stuck mash (see below).
Selection of a high quality malt, such as a fully-modified two-row barley malt, allows a more complete starch conversion at a single infusion temperature. The single infusion technique is most popular with small brewers, especially in England. The beer recipe described by William Harrison in his Description of England (1577) actually involves three infusions, each using water that has been brought to a boiling temperature. While this was obviously successful, a lower temperature (requiring, however, a thermometer, which is not a period device) optimizes enzymatic activity. I've opted for using the thermometer; what the hell.
A more specialized period technique, used to this day (esp. in Bohemia and Bavaria), is decoction. Decoction involves bringing part of the mash to a boil and mixing it in with the rest of the mash, thus gradually raising its temperature over time. There is some argument that decoction leads to softer, sweeter beers—the sort evidently favored by the wealthy in Medieval Sweden—but it seems unlikely that such a refined technique was widely employed in that period (save by certain monks who had lots of time on their hands).
The sugars that result from starch conversion are separated from the mash in the lautering process. First, liquid is drained through the false bottom of the lauter tun and added to the top again, a process known as vorlaufing: this allows the husks of the grain to settle against the false bottom and form a natural filter, preventing particles of grain from leaving the tun. Next, in the sparging process, hot water is sprayed on the mash while the wort (sugar solution) is drained through the bottom.
Historically, wort has been separated from the mash through a bed of juniper twigs (in Scandinavia), or through a hollow stick inserted into a hole (mentioned in some English recipes), or through layers of straw, husks, or cloth. A later recipe (1869) specifically mentions using a false bottom drilled with holes.
The actual brewing process involves boiling the wort and hops (or other flavoring herbs) together; the boiling time varies, but 60-90 minutes is typical.
Hops: There is some controversy over the earliest known use of hops in brewing. Hops were certainly known in England by the 16th century, and evidence exists that hops were used in Germany as early as the eighth century. The first definite reference to hops in brewing is by the Benedictine nun Hildegarde, abbess of Rupertsberg, 1098-1179.
Bittering hops (a.k.a. flavoring hops) are boiled longer to intensify the bitterness of the brew, while finishing hops are added towards the end of the boil, imparting more of a flowery character and aroma. Dry hopping involves addition of hops directly to the fermenter, to impart more flavor and aroma.
Hops were definitely recognized for their antimicrobial effect. William Harrison, in his 1577 Description of England, indicates that wort and hops are to be boiled together longer during the summer than the winter (to reduce the possibility of spoilage).
Today, there's no such thing as a "period" variety of hop. I purchase commercially grown hops of all varieties and use them according to desired style. The more "classic" hops are the Germanic "Noble" strains (Hallertauer, Tettnanger, Perle) and English strains (Kent Goldings, Fuggles, Northern Brewer). Some of my favorite domestic strains (Cascade, Chinook, Willamette) have a more flowery character. Other delightful, complex strains include Stisslespalt and Centennial. Many of these strains may successfully be used at all stages of the boil.
I generally choose to brew with pelletized hops, because of their superior bittering character. I sometimes use dried, whole hop blossoms or plugs to improve finishing. Hops do grow successfully in Flagstaff, despite frost and hail, especially against the warmer side of the house (south or east). I may try it out sometime.
Other ingredients: Juniper twigs, with berries, have historically been added to the brew in Scandinavia. If I want that effect, and my own junipers are not in season, I will add commercially available juniper berries to the brew. Heather and sage have been used in England; supposedly mugwort was also common prior to the widespread use of hops, but I haven't seen a (historic) recipe that specifically mentions it. Spruce shoots make an excellent addition to the boil, but I generally use spruce extract in such recipes (at the end of the boil).
Adjuncts: Adjuncts to the mash generally take the form of convertable starches, whereas adjuncts to the boil take the form of fermentable sugars. The use of honey or date juice as an adjunct in beer dates to Sumerian times. In Medieval times, the Welsh drink "Braggot" combined ale and honey. However, I have found no "period" recipe involving the simultaneous fermentation of malt sugars and honey or nectar; perhaps it was considered a waste of potential mead, but I have found the effect quite pleasant. Many recipes from the 18th century on substitute other sugars for malt to produce a "small beer" (apparently, this was originally a term referring to beer fermented from wort derived from an Nth infusion of the malt; i.e., the first one or two infusions would provide a stronger beer and a subsequent infusion the "small" beer).
Today, fermentable sugars such as malt extract, honey, fruit, brown sugar, molasses, and maple syrup are commonly added to the brew to add flavor and increase alcohol content. This is almost requisite in producing very strong beers such as barleywine ales and Imperial stouts.
Balance: Attention should be paid to the balance between the sweetness contributed by the sugars and the bitterness contributed by the hops and herbs. In most cases I try to go by the following rule of thumb:
Clarity: The addition of finings (e.g. Irish moss) to precipitate unwanted solids and clarify the beer is a common practice in England, though isinglass or ground oyster shells are more often used. Historically, clarity was not a major selling point until the introduction of the Pilsner style of lager in the middle 19th century. Nonetheless, there is evidence that clarity was of some value in Medieval times, judging from the writings of Andrew Boorde in the 16th century: "...Ale must haue these propertyes: it must be fresshe and cleare, it must not be ropy nor smoky... If the bere be well serued, and be fyned, and not new, it doth gualyfy the heat of the lyuer."
In 16th century England, hopped beers were called "beer" and unhopped beers were called "ale". Technically, however, ales are characterized by certain strains of yeast which exhibit a particular fermentation behavior. Ale yeasts are "top fermenting": that is, the cells concentrate at the top of the beer during their most vigorous activity. Depending on the strain, the yeast cells may actually ride the foam in the fermenter. Historically (and in many breweries today), ale yeasts were recovered by skimming the foam off the top of the beer, thus selecting for this characteristic.
Lagers: Technically, lagering refers to the storage of beer at low temperatures. Ideally, primary fermentation should take place at 41ºF - 48ºF, and lagering at close to 32ºF. The slower fermentation at low temperatures tends to involve a more complete consumption of sugars (greater attenuation) with fewer fruity esters and by-products commonly resulting in ales. As early as the 15th century, brewers in the Munich area would store beer in icy caves to keep it good through the summer. Yeast strains that settled to the bottom of the fermenter (instead of staying in the foam) were selected. Nonetheless, more methodical bottom-fermenting practices did not arise until the early 19th century.
As with hops, no "period" strain of yeast exists today. Michael Jackson, in his Beer Companion, does relate two anecdotes: 1) a porter fermented using yeast recovered from an 1825 shipwreck, and 2) a farmhouse brewer in Norway whose stirring stick carries yeast purportedly dating from Viking times. But brewers today are most likely to obtain their yeast from type cultures.
7. Secondary Fermentation
Secondary fermentation is more widespread among home brewers than commercial brewers. Racking the beer to a separate fermenter—removing it from the bulk of the yeast and hop residue—allows the remaining yeast to rejuvenate; also, some harsh flavors will volatilize. The chief benefit, however, is the relative purity of the remaining yeast that settles out, facilitating recovery.
Technically, conditioning the beer in the cask to promote carbonation is a form of secondary fermentation. Otherwise, historically the technique is uncommon except in certain specialized ales (the Kölsch style of ale, which involves secondary fermentation at low temperatures, is a notable example). Nonetheless, the benefits of the technique outweigh such considerations.
Blount, Gregory, of Isenfir (Greg Lindahl), "Age, Clarity, and Smoke in Medieval Beers", http://www.pbm.com/~lindahl/articles/age_clarity.html
Jackson, Michael, Michael Jackson's Beer Companion, Running Press, Philadelphia, Pennsylvania, 1993.
Listermann Manufacturing Co., "Wanna Mash?", Cincinnati, Ohio, year unknown.
Reese, M.R., Better Beer & How to Brew It, Garden Way Publishing, Charlotte, Vermont, 1978.
Renfrow, Cindy, A Sip Through Time, self-published, Sussex, New Jersey, 1994.
Scott, Franklin D., Sweden: The Nation's History, Southern Illinois University Press, Carbondale, Illinois, 1988.
The Brewery, "Technical Library", http://hbd.org/brewery/Library.html