Providing a quality chemical analysis service for regional hop growers and craft beer brewers in the Midwest.
Brewers Want Quality!
Brewers are fixated on quality! They chose their profession because they are proud of their craft and feel they have a superior product that people will pay for. Each year, more and more home brewers decide to enter the market and try their skills. Each year, the market gets tougher and tougher, putting more pressure on the entire craft-brewing industry. Each year, it becomes more difficult for brewers to build a clientele and tougher to hold onto the share of the market they have already developed. Quality and consistency are essential to their success and existence.
The brewer's customers are expecting a particular character
and flavor in the beer. Disappoint a customer by changing that beer's character
and they are very likely to remember that disappointment the next time they are
standing in the store deciding which brand to spend their money on. It might be
quite some time before those lost customers find their way back to that brewer's
brand again. Disappoint a brewer by messing with his brand loyalty and market
share and they are very likely to remember that disappointment the next season
when they are looking for a source of hops for their brewery. It happens!
Trust and Reputation
As we travel around the region and meet with brewers we occasionally run into brewers with "horror stories" about purchasing inferior hops from inexperienced or unscrupulous growers. Most brewers recall their own pitfalls as they struggled to establish their own business and market niche and graciously overlook the unintended transgressions. For a few, it will be a long time before they trust any local source of hops again. The damage done by those few "bad apple" experiences affects the reputation and therefore the sales of the entire regional hop-producing market.
Brewers understand that hops, probably more than any other regional crop, are a highly variable crop. They understand that quality and quantity are guaranteed to fluctuate from year to year, and they also understand that there is a marketing advantage to using locally produced ingredients in their beers. They also understand that local/regional hop production is a young and growing niche (much like their own industry!) and is worth supporting.
In general, brewers don't mind purchasing hops with a lower
alpha acid content or a lower essential oil content, if the hops are actually labeled
with the correct content. They can readily adjust their recipes to compensate
for variations if they know the variation. However, they get kind of touchy
when they brew a beer believing the content is one thing only to discover later
that it was actually more or less than advertised and there is not much they
can do, after the fact.
Bittering vs. Flavoring
Hops are used in brewing to both impart bitterness to the beer
and to add characteristic flavoring. The two uses draw on two different flavor
attributes of hops. Just as citrus fruits have a sour component that is separate
from their aroma/flavor component, hops cones have a bitter component that is
separate from their aroma/flavor component.
Boiling vs. Finishing
Hop varieties that contain relatively high levels of the bittering component are added to the unfermented beer (known as "wort") near the start of the boiling process. The extraction of these bittering compounds, known as alpha acids, is a slow process and requires 60 to 90 minutes of boil-time. Because of this, these hop varieties are often referred to as boiling hops.
The hop aroma/flavor components come from the "essential oils"
contained in the hop cones. Many of the chemical compounds that make up the
essential oils are not very soluble in water and evaporate quickly at boiling
temperatures. Because of this, these volatile (easily evaporated) compounds are
usually driven out of the boiling wort within the span of only 15 minutes. Thus,
hops used primarily for their aroma/flavoring character are typically added during
the last 5 to 10 minutes of the boil and are often referred to as finishing
hops. In fact one flavor-enhancing technique, known as dry hopping,
actually involves adding the finishing hops after fermentation has begun.
When harvested, the hop cones typically contain between 70% to 80% moisture by weight. To many beer officianados, these freshly harvested, untreated "wet" hop cones are at the very peak of their goodness at this instant in time and will only down-hill from here. It is just a matter of how closely to this peak of perfection they can be preserved. Brewing a beer with these wet hop cones is referred to as "wet hopping" a beer. Unfortunately, unless dried or used for wet hopping these cones quickly become mush and are then only good for composting.
To preserve the value of the cones, they must be dried.
Unfortunately, drying means subjecting the cones to lots of air at elevated
temperatures, two of the big three things to avoid. Drying must be done at as
low a temperature as possible and as quickly as possible to avoid un-necessary
exposure to air. Freeze-drying, by freezing the cones and pulling out the water
vapor in a vacuum system, would be ideal, but not practical in reality. If the
cones are not dried sufficiently (below about 12% moisture by weight) they can
easily be spoiled by mold. If the cones are excessively dried (below about 8%)
they become brittle and easily fall apart, allowing the oil and alpha acid
containing lupulin granules to separate out and settle to the bottom of the
To the brewer, "Freshness" is almost everything. Both the bittering component (the alpha acids) and the flavoring component (the essential oils) are affected by exposure to oxygen, light and heat. Light, air and heat are considered the three biggest threats to hop freshness after moisture. When storing hops it is important to prevent exposure to oxygen in the air by storing them in air-tight containers and protecting them from light by storing them in the dark as much as possible. All chemical reactions tend to run faster at higher temperatures. As a general rule of thumb, most reactions double in rate for every 10 degree Celsius (18 degree Fahrenheit) increase in temperature. Applying this concept in reverse for hops: every 10 degree Celsius decrease in temperature roughly doubles the storage life of hops!
The alpha acids degrade and become less bitter as they oxidize,
while a closely related set of compounds (called the beta acids) degrade into
compounds that add increased bitterness to the beer. though the perceived level
of bitterness remains abut the same as the hops "age", the quality or
characteristic of the bitterness changes. Something similar happens to the
essential oils: as they "age" (oxidize) their flavors change. Some essential
oils that had little or no flavor develop flavor (some good and some bad) with
time and exposure. Other essential oils lose the flavors that they had.
Typically, aged hops take on a variety of cheesy, oniony and garlic flavors
that are not particularly well suited to beer.
The Hop Storage Index
The decrease in alpha acids and the increase in their oxidized
counterparts can actually be measured by a spectroscopic technique that uses
ultraviolet light. The ratio of oxidized remains to unoxidized alpha acids
provides a numerical value called the Hop Storage Index (HSI). The values range
from about 0.24 to around 2.40. The lower the value the better the "freshness"
of the hops.