Ingredients

On April 23rd, 1516
the *Reinheitsgebot*, or Bavarian
Purity Law was enacted, stating that only water, barley, and hops were to be
used in the making of beer. While these do constitute the primary ingredients
in the making of beer, there are a lot more available to us, including the one
they were unaware of, and the most important: yeast.

**Water**

Water is used during many stages of the beer-making process,
but not just any water will do. The water from different sources can be almost
as different as the beers they produce. The mineral content (or “hardness”) of
water has had a significant impact on the signature beers of Europe.

Pilsners owe their mild character to the soft water of Plzeñ.

In comparison, Munich’s lagers are more aggressive, due to the
higher levels of calcium and magnesium in their source water.

With even harder water being used, Dublin is now famous for
their stouts.

Nowadays, however, brewers can chemically manipulate their
water to suit their needs. For example, a commonly heard term in beer-making is
the “Burtonising” of water. This is the process of adding sulphate, often in
the form of gypsum (a very soft sulfate mineral composed of calcium sulfate
dehydrate) to replicate the composition of the water used in Burton-Upon-Trent,
a town in England famed for the hoppiness of their beers.

**Starch Source**

Starch provides the fermentable material for making beer,
and also is a key determinant of the strength and flavour of the beer.

The most common starch source is malted grain. Barley is the
most popular choice, as its husk contains an enzyme that facilitates conversion
of starch to sugar, which the yeast will then feed on. However, other options
are:

* Wheat
* Rye

* Oats

* Rice

* Corn

* Sorghum

* Buckwheat (which is not actually in the cereal/grass family, but closely related to rhubarb and sorrel)

Each type of starch source can produce different qualities
in a beer. Barley imparts a firm, clean sweetness; wheat has a tart, quenching
quality; rye is spicy almost minty; oats add a silky smoothness. A beer like
Triple Karmeliet features the qualities of the oats, barley and wheat, all in
the same glass.

**Hops**

First recorded as being used in beer in the 9th
century, hops were not the primary source of flavouring in beer until the 16th
century. Combinations of various aromatic herbs, berries, and even ingredients
like wormwood would be combined into a mixture known as *gruit* and used as hops are now used.

* Hops are not just a one-trick pony. They provide many valuable services in the making of beer.

* The resins of hops give bitterness which balances the sweetness of the malt.

* The oils impart “hoppy” aromas that are floral, citrusy and herbaceous.

* Hops have an antibiotic effect which favours the activity of brewer's yeast over less desirable microorganisms.

* Hops aid in “head retention,” assuring you a nice, frothy beer.

* The acidity of hops acts as a preservative.

Hops can be employed in a number of forms: whole cones,
pellets, powder, or extracts. Purists will swear that only whole cones
(sometimes referred to as flowers or, less commonly, strobiles) are the only
acceptable form of hops. However, they have a limited shelf-life, are more
expensive, and stick to everything after cooked, necessitating a thorough
cleaning of one’s equipment.

The use of hops of in the making of beer requires a thorough
understanding of both your ingredients, and the process. Hops added at the
beginning of the boiling of the wort will impart bitterness, but very little
additional flavour or aromas, as the essential oils evaporate. These are
referred to as “bittering” hops.  These
will be high in alpha-acids, which also provide the anti-bacterial effects. “Aroma”
hops tend to be lower in alpha-acids, but higher in beta-acids and essential
oils. These add not only aroma (derived from mostly the essential oils), but
flavour, as well (from both the essential oils and beta-acids). They tend to be
added later in the boil, for a couple of reasons: Not only does one not want
the essential oils to evaporate, but hops higher in beta-acids can impart
off-flavours of rotten vegetables if boiled too long. Hops added within the
final 30 minutes of boil impart flavour. Those added within the final ten,
aroma. Aroma hops can be added after the wort has cooled, while the beer
ferments, a process known as “dry-hopping.” This adds even more aroma. Anyone
who says they don’t like hops in their beer has no idea how important they are
to the finished product.

European “Noble” hops (Saaz, Spalt, Hallertau, and Tettnang)
have about 5-9% alpha acids by weight, and the newer American species typically
range from 8 to a staggering 19% AABW.

**Yeast**

Yeast is the microorganism that is responsible for
fermentation in beer. Yeast metabolises the sugars extracted from grains, which
produces alcohol and carbon dioxide, and thereby turns wort into beer. In
addition to fermenting the beer, yeast influences the character and flavour by
producing esters (fruity aromas and flavours), phenols (spice), and, sometimes,
ketones (buttery, caramel-like taste). Different types of yeast can result in
wildly different beers.

Nowadays, with the multitude of yeasts identified and
categorized, one can select a culture (or, quite often, multiple cultures) from
a list to brew the exact style of beer they plan on making. Some will impart
incredibly distinctive pronounced notes, while others will be very clean, and
lean. BrewTek CL-320 is a yeast that is used extensively in the making of
Dubbels and Tripels, as it produces a complex, dry, fruity, estery profile.

The most famous yeasts in Belgium, however, are the wild
ones found in the Senne valley, where the dry, sour, vinous lambics are
produced; specifically, Brettanomyces bruxellensis and Brettanomyces
bruxellensis. Despised, for the most part, in the wine-making new world for
being responsible for up to 90% of the spoilage of red wine, these yeasts give
lambics their distinctive “saddle-leather” and “barnyard” aromas. These yeasts
have been cultured and incorporated into the making of Flanders Red and Old Brown Ales;
notably, Petrus Oud Bruin and Duchesse de Bourgogne, which share some of the
qualities of lambics.