Yakima Chief – Hopunion has an extensive Quality Control department that includes two laboratories which are responsible for all quality checks from harvest to final product. All analyses are done in accordance with The American Society of Brewing Chemists (ASBC) and European Brewing Convention (EBC) methods. The working copies of these methods are maintained in YCH’s ISO 9001 standard operating procedures (SOPs). Within the lab, technicians perform a variety of hop analyses that aid in the production of YCH HOPS’ premium hop products, gathering data such as brewing values (alpha and beta acids), moisture, oil content, dry matter and more.
There are four different methods that YCH uses to measure various brewing values in hops:
● The most common method of analysis is by UV Spectrometer and is often referred to as brewing value analysis. It provides alpha and beta acid concentrations as well as Hop Storage Index (HSI), which states to what degree a hop product is oxidized.
● The next method is by High Performance Liquid Chromatography (HPLC) which provides alpha and beta acid concentrations by using the International Standard Extract produced by the ASBC and EBC; it also provides the percent cohumulone and percent colupulone.
● The remaining two methods provide alpha acid concentration by utilizing titration and conductance as described in EBC method 7.4 and 7.5.
● Both YCH labs participate in industry ring analysis to track the accuracy of the results.
In addition to acid measurements, YCH’s labs also measure percent moisture by oven or distillation, total oil by distillation, and oil components by Gas Chromatography (GC) throughout the harvest season. Each delivery of 200lb hop bales is tested at the receiving site for moisture and temperature. Once bales pass the initial quality control check, samples are taken from every tenth bale and placed in a bag making a composite of the entire delivery. The lab grinds these samples and analyzes them for alpha, beta and HSI. Any subsequent deliveries of the same lot are treated the same. Once the lot closes (is done delivering), the lab combines all of the samples and performs analysis for total oil and oil components. Data is then entered into YCH’s ERP allowing lots to be chosen for samples, leaf repacks, and/or pellet blends. The goal is to make consistent blends of high quality pellets for all customers.
Hop analysis doesn’t end with harvest, in fact, it’s just the beginning. Once production begins on the new crop, samples are delivered to the lab to check quality on all products. For leaf repacks, where bales of hops are repackaged into smaller quantities, samples are taken from the bale lot to the lab for brewing value and oil analysis. YCH compares the new data collected at repackaging to harvest data to better understand how the hops are storing. For pellet lots, samples are taken at an interval determined by the number of pallets as described in YCH’s standard operating procedures. Each sample of the lot is sent to the lab for brewing value analysis. The lab uses this data to track alpha variation within the pelleting process and works closely with production personnel to ensure all pellet lots are of a consistent quality. When the lot is finished, the lab combines all the samples to make a composite and analyzes for total oil and oil components, by HPLC and lead Conductance Value (LCV). The comprehensive data collected within the lab is used to provide customers with accurate and valuable information.
Pellets headed to the extract plant to produce CO2 hop extract are analyzed before and after extraction to track extraction efficiency. Once extraction of the pellet lot produces enough CO2 hop extract to make a complete lot, the extract is sampled and the lab analyzes by UV or HPLC for total oil. The alpha value produced by either UV or HPLC is used to calculate how many grams of extract is needed in a tin to meet the specified grams of alpha required. All of the lab results for the final product are made available to customers via a Certificate of Analysis.
YCH also has a laboratory service section, Alpha Analytics®, which offers third party lab services to hop growers and micro brewers nationwide for hops and beer. The available analysis services for hops include dry matters, moisture, brewing values, and total oil with oil components. Before harvest, growers can send wet hop cones to the lab for analysis. Dry matter tests are performed on wet cones, telling the grower how much dry matter, or conversely moisture, is present in their hops. As hop cones ripen, the dry matter increases to an optimum point that ensures the best pick-ability of the cone from the bine. In addition, the % alpha and oil increases as the lupulin gland matures. The brewing values, total oil, and oil components methods require that the hop cones be dried to 8-10% moisture. Once maturity is reached, the alpha and oil will start decreasing as the hop cone over ripens, resulting in the overall quality reducing as the concentrations of alpha and oil decreases. Pre-harvest lab analysis can help ensure that hops are picked during the ideal harvest window and contain their peak total oil and brewing values.
The beer testing service by Alpha Analytics® is offered to both professional and home brewers. Analyses include IBU, pH, color, and batch analysis using Anton Paar that provides results on alcohol, extract, calories, and more. All analyses are done according to standard methods to ensure accurate results.
The goal of YCH’s Alpha Analytics laboratories is to help brewers of all sizes produce the best beer possible by providing accurate results for their hops and beer.
For more information regarding these services, please visit www.alphaanalyticstesting.com.