Midwest Hop and Beer Analysis, LLC

Providing a quality chemical analysis service for regional hop growers and craft beer brewers in the Midwest.



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Hop Testing FAQ's


Top Why Test Who Tests Us Certification

Why Test?

We have developed a PowerPoint presentation, complete with slide transitions and animations, which you can view at Why_Test.pptx. Since not all platforms are cross-compatible, We've converted the original presentation into a PDF type format available as Why_Test.pdf. The original slide transitions and animations are not available in this format, but the information is there and the file should be a little faster to download.
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Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils

Who Tests Us?

Midwest Hop and Beer Analysis, LLC is a supporting Corporate Member of the American Association of Brewing Chemists (ASBC). We also are active participants in the ASBC's "Check Sample" program, in which each lab participating in the hop analysis program receives monthly test samples of hops all drawn from one particular lot of processed hops for analysis. Samples preparations are rotated through a three month cycle of pelleted hops, powdered hops and hop-extract. The hop varieties, storage conditions, etc. are unknown to the receiving labs. Each lab analyzes the sample for α-acid and β-acid content and the Hop Storage Index (HSI) and submits their findings in a report to the ASBC. The ASBC tabulates the values from all of the participating labs and publishes a monthly update of the results and an accompanying statistical analysis. Currently, there are about 20 National and International labs that participate in this service on a regular basis, with four or five more submitting results sporadically. We are extremely proud of how well our lab compares in relation to the performances of many of the other labs.
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Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils

Pre-Harvest Testing Packages

Pricing

If harvesting for alpha acids content,
test for alpha acids content.

If harvesting for moisture content,
test for moisture content.

Due to the repetitive nature of pre-harvest testing, growers everywhere have asked us to find a less expensive test for determining the proper time to harvest. I have looked into a variety of options and have decided to offer a less labor-intensive version of our standard test.

We usually run duplicate tests on samples, but will only run single samples of these tests to reduce time, labor and material usage. We will also leave the moisture testing component up to the grower, as an additional cost-cutting measure. The reduction in labor and time also ensures we can continue to provide rapid (24-hr) turn-around times on these tests!

Determining Moisture and Essential Oil Levels on the Farm - Instructions

Though your farm-determined moisture and oil levels won't be as accurate as lab-determined values, they don't need to be accurate for the purpose of determining harvest-readiness: they only need to be consistent! If your moisture values are consistently high or consistently low, your adjusted α-acid or essential oil values will also be consistently high or consistently low. However, the Pre-Harvest test is designed to monitor the change (increase) in α-acid or essential oil values as they approach a peak value and level off. If the technique is consistent the results will peak and level off at the same time as the actual values.
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Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils

Harvest Test Package

Pricing

We use the testing protocols developed by the American Society of Brewing Chemists (ASBC) and accepted as standards in the industry. This test package utilizes three ASBC protocols: ASBC Hops-4C "Moisture Content by Routine Air Oven Method", ASBC Hops-6A "Alpha Acids and Beta Acids Content by Solvent Extraction and Spectrophotometry", and ASBC Hops-12 "Hop Storage Index by Solvent Extraction and Spectrophotometry".

This test-package is designed to serve as a check on the current condition of the hop sample. All samples are processed in small batches so they can be closely monitored throughout the process. In addition, we often choose samples at random on which to run duplicate tests, as part of an internal check/control system. No system, however, is totally flawless. Contact us if any concerns about test results arise and we will gladly run a duplicate test on the sample, at our expense. (Please provide the requested sample amount in order to cover any need for duplicate tests.)

For the grower, this test-package provides accurate information on the current Hop Storage Index value and the levels of moisture, α-acids and β-acids in their product. It also provides predictions of what the α-acid and β-acid contents would be if the moisture content were adjusted to 0% and 10% moisture by weight. The 0% moisture values are a handy starting point for calculating predictions at any other moisture content (see the Calculations section), while the 10% moisture values provide a common reference point.

For the brewer, this test-package provides a way to accurately verify the condition the hops at the time of purchase and, through changes in the Hop Storage Index, to monitor the condition of the hops as they sit in storage.
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Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils

Certification Test-Packages

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These test-packages have been developed at the request of both brewers and growers to meet a marketing certification need and to develop a higher level of trust between hop producers and hop consumers. It also meets the needs of a growing industry that is intent on establishing itself as a proud source of high-quality, family-farmed and locally-produced hops. (Think of the well earned reputation of locally grown produce!)

The Certification Test-Packages bring that same level of quality assurance to the testing process and to the products being tested. Each test is conducted a minimum of two times. Any discrepancy between the results of those two sets of tests will prompt additional repeat tests. Moisture testing will involve the definitive "Moisture by Distillation" method.

The α-Acid version includes moisture content by distillation and the Hop Storage Index, the alpha-acid content and the beta-acid content as determined by the standard "Solvent Extraction and Spectrophotometry" method. The Essential Oil version includes moisture by distillation and the total essential oil content, also by distillation. (Be sure to provide enough material for testing, as specified on the testing page)

Seeing confirming documentation presented by the grower/provider is an additional indication of their willingness to stand behind the quality of their product and go the extra mile to care for their product. (If they are willing to come forward on their own with documentation on their product, you can be pretty sure they step up to the plate on other, behind the scene, activities that enhance the quality and reliability of their product.)
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Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils

Moisture Testing

Pricing

Moisture content is a factor in the storage ability of the finished product: too dry and the cones fall apart and the lupulin settles to the bottom of the container; too moist and mold degrades the quality of the hops. When pelletizing: too dry and frictional heat in the pelletizer causes degradation of the bittering acids and drives off some of the essential oils in the hops while to much moisture will again lead to spoilage. The ideal moisture content is considered to be around eight to ten percent.

There are many methods that pertaining to drying plant matter: some are consistent and work well but are impractical on the desired scale, while others are practical but the results are not consistent or are erroneous. The definitive method for determining the moisture content in hops involves a somewhat complex, solvent-based distillation system. The results are repeatable, precise and accurate, but it is not a very practical system (the hot solvent presents an explosion hazard). Drying in an oven is easy and practical, but to be repeatable, precise and accurate it requires a tightly controlled and highly consistent environment.

Fortunately, most of the time, a food dehydrator can provide results with enough precision and accuracy to provide meaningful results. Lower temperatures require longer drying times but reduce the problems of evaporating some of the more volatile (more easily evaporated) essential oils. Plus, there is always the risk that the sample never really gets completely dried. Higher temperatures can ensure that drying goes to completion and requires shorter drying times, but there is an increased risk of driving off the lighter essential oils. It is a balancing act that will involve some at-home trial and error, and patience.
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Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils

Essential Oil Testing

Pricing

When asked to explain the role of essential oils in hops, I often ask people to think about citrus fruits like lemons, limes, oranges, grapefruits, etc. They all contain the same sour-tasting compound, citric acid, and the same sweet-tasting compound, sugar, but they all smell and taste different due to differences in the essential oils they contain. Hops all contain the same bitter-tasting compounds, the α-acids and β-acids, but they all smell and taste different due to the different essential oils they contain.

Some hops are prized for their excellent bittering ability; and the more bittering ability they have the more prized they are. Other hops are prized for their excellent aroma and flavoring abilities; and the more flavoring ability they have the more prized they are. Hops that are used primarily for their bittering ability are often referred to as "bittering hops" or "boiling hops" because they are often added to the kettle at the beginning of the boil and remain there throughout the boil. Hops that are used primarily for their aroma and flavoring ability, however, are commonly referred to as "finishing hops", due to the fact that they are added near the end of the boil, in hopes that their prized flavor and aroma doesn't all get boiled away.

For those hops that are prized for their bittering ability, when to harvest depends on when the bittering component, the α-acids, are near their peak concentrations and quality. For those hops that are prized for their aroma and flavoring ability, when to harvest depends on when the flavor components, the essential oils, are near their peak concentrations and quality. However, the α-acids and the essential oils don't always reach their prime at the same time.

If harvesting for essential oils content,
test for essential oils content.

If harvesting for moisture content,
test for moisture content.

Top Why Test Who Tests Us Pre-Harvest Harvest Certification Moisture Essential Oils