| AROMA |
|
| Much
is spoken of the quality and intensity of dried hop aroma. These are
strong varietal characteristics. There appears to be a general relationship
between the type and heaviness of a hop aroma and the flavor and aromatic
properties of beer. |
| BETA
ACID |
|
| A
soft resin component, beta-acids are not bitter in the natural or
isomerized form. Some of the oxidation products do provide bitterness,
and the beta-acids can be chemically transformed into light stable
bittering forms. |
| CO-HUMULONE |
|
| The
alpha acids exist in three analogous forms, humulone, ad-humulone,
and cohumulone; and the proportions of these analogues vary markedly
with variety. Varieties with relatively low co-humulone levels are
strongly favored. |
| CONE
STRUCTURE |
|
| There
are certain physical properties of hop cones while unimportant in
the brewing process, are strongly characteristic of a particular variety.
Light loose cones are much more prone to shatter during harvesting
while heavy dense cones pick beautifully as they roll well and hang
together. |
| DISEASE
REACTION |
|
| Varieties
can display a wide range of reaction to various hop diseases. Of great
importance in the U.S. are the fungal disease downy mildew and the
viral disease ring-spot. |
| DRY
BALING |
|
| Some
varieties are more difficult to dry than others and some tend to shatter
more than others when being baled. Growers can adjust practices to
accommodate these peculiarities, but the more difficult a variety
the more likely it is that mistakes will be made. |
| GENERAL
TRADE PERCEPTION |
|
| Over
a number of years, a hop variety will find a particular role or niche
within the brewing industry, and its particular properties will become
well known and accepted. This general perception is helpful to brewers
considering the use of a variety new to them. |
| GROWTH
HABIT |
|
| Hop
varieties vary widely in structural aspects such as general vigor,
lateral length, and the overall vine structure. These type of characteristics
can make a variety more or less easy to pick and handle. |
| LUPULIN |
|
| Hop
lupulin may vary in color from pale yellow to an intense golden color.
It is not known if lupulin color affects brewing performance, but
it is a fairly strong characteristic of a variety. It is certain that
the bitter hops have much greater quantities of lupulin than the aromatic
types. |
| MATURITY |
|
| This
is a statement of the time in the hop harvest season at which the
particular variety reaches optimal maturity. Harvesting in the United
States occurs from about August 20 to September 20. |
| MYRCENE,
HUMULENE, CARYOPHYLLENE, FARNSENE |
|
| The
four major components of the essential oils and between them they
account for about 60-80% of the essential oil of most varieties. The
compounds are all highly volatile hydrocarbons; and during boiling
of the wort, most if not all of them, are driven off and contribute
little to hop flavor and aroma in beer. |
| PEDIGREE |
|
| Brief
remarks about the ancestry of a variety. In the case of very old varieties
like Saaz or Hallertau, there is no ancestral information. We know
only that this particular varietal type was selected over many years
by growers and brewers in a particular area. More modern varieties
can often be traced back through two to three generations of crosses
often involving other known hop varieties. It is important to note
that the qualities of a hop variety are only partly determined by
the genes it receives. |
| PICKABILITY |
|
| This
is another characteristic which is of direct concern to both grower
and brewer. If a hop is known to pick well, one can expect a good
clean sample. If a hop is difficult to pick, one is more likely to
see shattered cones and a higher proportion of leaf and stem in a
sample. |
| STORAGE |
|
| Oxidation
of alpha acids removes their ability to be isomerized to the required
bitter isomers. In comparable circumstances, some varieties lose a
greater proportion of their alpha acids to oxidation than others do.
Cold storage and anaerobic conditions can delay oxidation. Some oxidation
of essential oil components is necessary to produce compounds thought
to be important in beer flavors, so controlled aging is important
for hops required for both bittering and aromatic properties. |
| TOTAL
OIL |
|
| This
characteristic varies widely with seasons, varieties, and growths
from 0.5 mls to about 3 mls per 100 g of hops. While the soft resin
are responsible for providing the bitterness of a beer, the quantity
and composition of the essential oils are responsible for the amount
and quality of hop flavor and aroma in beer. |
| YIELD |
|
| This
is the kiln dry weight of hops normally produced by a variety in commercial
production in the U.S. On an average, the aromatic types tend to be
lower yielding and more highly priced than the bitter types. |
|