Quality – HPA

Our stance on hop selections

Pixel3 — Sun, 18 Apr 2021 23:51:50 +0000

HPA recognise the important role that hop selections play in the beer industry. We understand flavour profile can differ from season-to-season and lot-by-lot. For this reason, brewers who visit US hop farms are often invited to select the specific bale lots they want to purchase and ultimately use in the brewery. Their decision to offer selections is largely driven by variable quality outcomes due to a large number of independent growers who are spread across diverse geography all contributing to the yield of a single hop variety. You can view a video of sensory experts conducting our crop 2021 US hop selections below as well as listen to our Head of Sales & Marketing Owen Johnston share his thoughts on this topic with Matt Kirkegaard from Brews News here, or you can just keep reading.

You know how some people say making beer is easy because there are only four key ingredients? Well we all know there are a number of things a brewer can do differently to optimise the process specific to their brewery setup, and create a different outcome to their fellow brewers. Growing hops is no different. There are a number of things a grower can do differently to optimise the process specific to their farm. This can lead to significant variability in quality outcomes because of differences in fundamental decisions around fertiliser and irrigation practices, as well as secondary matters such as winter ground cover cropping, weed control, soil compaction, terrain and terroir.

As Oceania’s regional representative of the global BarthHaas group, we are responsible for establishing effective procurement procedures and coordinating a supply chain that will deliver international hops with consistent quality outcomes for our brewing customers. Our role within the global network, the close relationships we hold, and the combined purchasing strength of our contracted brewing customers afford us priority at the international selection tables. This ensures we are presented with quality hops to select from that are supported by significant quantities. To further optimise the outcomes of this process we encourage our brewing customers to regularly communicate which variables they value most and what analytical ranges they want to see in the end product. This is particularly important, since the hops presented at selections are just a small portion of the total crop. Joining us at the international selections tables is an opportunity we offer some of our brewing customers each year to better understand the process, have input into the selected batches and know who else had input into the selected batches, while still being able to hold us accountable for the quality of the end product.

Our involvement in international hop selections may seem contradictory to our decision not to offer Aussie hop selections. On the contrary, we are in a unique situation compared to the international growing regions that are experiencing increasing diversity. HPA are a relatively small, independent, vertically integrated business that has sole custody of our proprietary hops across all stages of the hop production process, from cultivation and growing all the way through to packaging and sales. They are cultivated specifically for our Australian growing regions that produce just 1% of hops around the world. Our farming practices are governed by a no-nonsense quality management system that adheres to the internationally recognised ISO 9001 and HACCP certifications, which ensures best practice and procedural uniformity across both growing regions. The timing of our post-harvest production process also has a particularly significant impact on quality outcomes. Fortunately, our business model and substantial infrastructure capabilities currently allow us to ensure the entire crop is packaged within eight weeks of finishing harvest.

An intimate understanding of our proprietary hops and an exceptional level of quality control over the hops from bine to brewery is our most important point of difference compared to other businesses in growing regions that choose to offer selections. This doesn’t mean we don’t experience some variability in quality outcomes, but we can minimise these variabilities by being in full control of the whole crop from the very beginning to the very end. As a result, instead of offering selections we have made it our mission to deliver the highest possible quality outcomes with the lowest possible flavour variability through blending. This means we distribute equitable hops to all of our brewing customers. Some might consider this approach egalitarian, but it’s our objective to manage our proprietary hops in a way that will deliver the best long-term outcomes and allow brewers to trust their performance in beer.

We undertand our approach to selections does not embrace the nuances of a given hop variety’s flavour profile, which can really excite some brewers. But we also know the majority of our brewing customers would admit they are under a lot of commercial pressure to make consistent beer. No matter how much we might want to celebrate choice and diversity in beer, there is a consumer confidence piece we need to consider. When a beer drinker falls in love with one of our brewing customers beers, whether it be on tap at the pub down the road or off the shelf from their local bottle shop, it’s important that beer tastes the same next time they drink it. This consistency encourages a level of brand loyalty that forms the foundation for future growth. We see it as our role to help our brewing customers achieve future growth by presenting consistent, high quality hops and giving them one less production challenge to face.

All current and potential brewing customers are encouraged to visit our farms during harvest so they can meet our team, better understand our production process, observe our commitment to consistent flavour profiles through quality management, and come to appreciate the connection between brewers and hop growers who really are mutually dependent on one another.

Biosecurity is everybody’s business

Pixel3 — Thu, 13 Feb 2020 09:35:46 +0000

Biosecurity plays a critical role in the Australian hop industry. It keeps our hops free from the world’s most damaging pests and diseases.

Managing biosecurity is the shared responsibility of our staff and every visitor to our farms, as people can unintentionally carry pests, diseases and weeds without even realising.

To limit the risk of these threats to our hops, we ask our visitors to:

Ensure vehicles, equipment and clothing are clean and free from pests and other plant material prior to their visit
Park in the designated areas
Sign the visitor register, clean and disinfect boots at the farm office immediately upon arrival

The biosecurity legislation of each Australian state and territory enforces restrictions on the movement of certain items to protect their unique environments and valuable agricultural markets.

In Victoria, Rostrevor Hop Gardens and Buffalo River Valley are protected by legislation that is focused on preventing any biosecurity emergencies that could affect Victoria and Australia.

In Tasmania, Bushy Park Estates is protected by the island’s natural barrier from mainland Australia and overseas, as well as some of the strictest biosecurity legislation in the world. This is enforced by biosecurity officers and detector dogs. In particular, fresh fruit and vegetables, cut flowers, plants, animal and fish products, seeds, soil and other agriculture related products are restricted or prohibited from entering the state. Pests, diseases and weeds may also travel unseen in mud, or lodged in the crevices of recreational machinery, vehicles and other gear. For this reason, it is important these items are checked, cleaned, disinfected and dried before entering Tasmania.

Fortunately for our international visitors, we are assisted by the Australian Government who operate across the whole biosecurity continuum with offshore, border and onshore measures. They ensure all international travelers and their baggage are screened upon arrival in the country, using x-ray machines, detector dogs, physical inspection and questioning. To ensure you are prepared, check what to do:

You should also check what goods you can bring into Australia each time you travel as import conditions can change. For border clearance do not carry any fresh fruit or vegetables, plants, seeds, meat, animal or wood products, and ensure that your footwear, sporting and recreational equipment is dry and soil free.

Help keep our hops disease free, so you can continue making great tasting beer.

Using hop analyses to optimise the brewing process

Pixel3 — Thu, 21 May 2020 11:21:48 +0000

They say there’s no such thing as a bad beer, but some do taste better than others. We take pride in our hops, and the beers our customers create with them. That’s why quality management is so important to us. We have a range of quality management procedures in place to ensure our farms and facilities are ISO 9001:2015 compliant and HACCP certified. This includes analysing around 3,000 hop samples over the course of harvest, which contribute to more than 25,000 measurements that help us meet customer expectations of consistent hop flavour outcomes year-on-year.

Understanding pre and post-harvest hop analysis is key to producing beer of consistent quality. Hops are a natural ingredient produced by a highly specialised horticultural system in temperate regions around the world, which means they are subject to seasonal variation. Hop analyses give hop growers and brewers alike the opportunity to optimise their processes to achieve consistency and efficiency. This is a very technical topic, so if you don’t have the time or capacity to digest it right now, reach out to your local Sales Rep and they’ll talk you through the high points.

For those of you still with us, the hop sampling and measurement process spans a period of six months. During this time, we go through three phases on quality testing – pre-harvest in-field samples, harvest bale samples and post-harvest packaged product samples:

Pre-harvest sampling tracks the development of hop cones and the accumulation of alpha acids and essential oils across our farms. We systematically sample every paddock across our farms at least three times pre-harvest, with the final sample taking place within 36 hours of the paddock being harvested. The information we receive from these samples confirms whether our planning around harvest logistics is correct, and informs the picking sequence for varieties that cover significant acreage. This picking sequence ensures we capture the best possible representation of each variety year-on-year.

We input proprietary predictive models into a Near-infrared (NIR) analytical system to assess the samples’ alpha acids and oil content. Gland fill, dry matter and cone weight are also measured at this stage. All of these measurements follow a fairly consistent pattern of development in the lead up to harvest, which occurs when the paddock reaches our ideal values. The below graph and associated heatmap provide a visual representation of the day in year that these values are typically reached. However, events such as hot and windy days, heavy rain, flooding or frost can accelerate development.

During harvest we take several composite samples from each lot of hops once they have been baled. Alpha acids and moisture content are the main focus at this point with all measurements produced through NIR. This is crucial to the blending process that enables us to achieve consistent quality outcomes for each variety year-on-year.

Post-harvest we conduct further testing on each lot of final packaged product, including pellets and flowers. The information we receive from these tests is what brewers see on our certificates of analysis (CoAs).

Brewers can use CoAs to anticipate process changes required to achieve consistent brewing results, and to verify compliance with hop specifications. Our hops are supplied in sealed, oxygen barrier laminated foils that have been back-flushed with carbon dioxide and packed in cardboard cartons. Each carton is labelled with variety, producer, crop year, production date, lot identification number, product type, net weight and bittering potential (alpha acid contents and analysis method). There is no standardisation of hop CoA information in the brewing industry. In their most basic form a CoA will cover the same information as the carton labels, but we also choose to include essential oil content, moisture content and agricultural chemical residue reporting.

Each hop analysis has a different siginificance in brewing:

Since hops that are used in brewing are a food ingredient we are required to ensure all typical food safety requirements are met, and can also provide allergen and residue statements if required.

It is also important to remember that hop CoAs and label information describe the hops at the time of packaging. Chemical changes that affect performance in beer may occur if the hops are transported, stored and/or handled improperly at any stage of the supply chain. We work closely and collaboratively with our contractors to ensure this risk is managed effectively, so that our customers can continue making great tasting beer.

Hop storage techniques that preserve impact in beer

Pixel3 — Tue, 02 Jun 2020 11:31:05 +0000

We recently collaborated with the Independent Brewers Association (IBA) to create a guide to interpreting hop Certificates of Analysis (CoA). A CoA describes the hops at the time of packaging. To preserve their impact in beer, we seal our hops in oxygen barrier laminated foils that have been back-flushed with carbon dioxide. But the degradation of alpha acids and essential oils happens very quickly once the foils are opened and the hops are exposed to oxygen. Luckily, there are some simple and cost effective steps that brewers can take to keep their hops fresh and their beers consistent.

Unopened foils will last up to three years in storage temperatures of 1°C-5°C. But we know that not every foil will be used in its entirety as soon as it’s opened. Once a foil is opened the oxidisation of alpha acids begins almost immediately, and the more volatile oils (ie. Myrcene) are rapidly lost. To limit these chemical changes that directly effect impact in beer we recommend that brewers:

Refrigerate hops in storage temperatures of 1°C-5°C (or lower)
Reseal opened foils
Date and time stamp opened foils

Storage

Hops should be stored in temperatures of 1°C-5°C (or lower) at all times. Storage stability varies from variety to variety. Each hop has different levels of natural antioxidants, and varying susceptibility to oxidation. This can cause them to lose quality faster, even under identical storage conditions.

Regardless of variety, exposure to oxygen, heat and light should be avoided to preserve impact in beer. The quality of hops exposed to high temperatures will rapidly degrade. The higher the temperature, the more they will degrade. This effect has been shown to halve for every 15°C drop in temperature. And hops exposed to high levels of UV light can produce off or cheesy flavours in beer.

Hop pellets degrade more slowly in foils than whole hops. Their compact shape keeps out a lot of oxygen and allows them to be easily vacuum packed to further slow the loss of alpha acids and oils. They also take up less storage space, making it more practical to keep them refrigerated.

While hops are occasionally shipped via refrigerated freight, this is often not the case. Depending on the length and logistics of the journey, hops may be exposed to ambient temperatures for periods of time. Short durations typically have no impact on hop quality, but should be limited to no more than a few days where possible. Hop quality only becomes a factor if pellets are exposed to oxygen, direct UV light, or extreme temperature fluctuations during transit and storage. Foils are specifically designed to protect hops from both exposure to oxygen and direct UV light.

Resealing vs Wrapping

Brewers should not open foils until necessary. Once opened, the best thing to do is reseal any remaining hops in the foil using a commercial chamber vacuum sealer and return to storage temperatures of 1°C-5°C (or lower). The two key features a brewer should look for in a vacuum sealer are to ability to comfortably hold a 5kg foil, and pre-installed inert gas back-flushing capability or the option to fit a separate gas back-flushing kit. These devices start at AUD$5,000 when brand new (example here), but you can often source them second hand from restaurants. They are a particularly good investment for those with brewpubs, as it can be used in both the brewery and the kitchen. Ideally, brewers should reseal the original foils to retain the benefits of the oxygen barrier. But the next best thing is commercial grade vacuum bags. This method should result in a foil or bag that is tightly sealed while still allowing the hops to move around.

If vacuum sealing is not an option, brewers should simply squeeze all oxygen out of the foil then wrap and tape so it is as airtight as possible. The hops should then be placed back in storage temperatures of 1°C-5°C (or lower).

Best Before Date

Ideally, once a foil has been opened the hops should be used within a few days to minimise loss of alpha acids and oils. However, any remaining hops that have been resealed or wrapped in their original foil should last up to two months depending on the variety and overall exposure to oxygen.

If the re-sealed or wrapped hops are no longer in their original foils, brewers should label them with their variety, lot code, crop year, alpha acid percentage and weight before returning them to storage temperatures of 1°C-5°C (or lower). This will help determine their expected impact in beer at time of use.

One common test to determine the storage stability of a particular variety is to measure the amount of alpha acids lost over a six month period at 20°C. There is a direct relationship between the losses and the Hop Storage Index (HSI). If you know original alpha acids and the HSI, you can predict alpha acid losses and adjust your recipe accordingly to create more consistent beers. Click here for step-by-step instructions.

Stop the import of damaging pests and diseases

Pixel3 — Tue, 30 Jun 2020 11:40:28 +0000

The Australian hop industry is fortunate to be free from many damaging pests and diseases that affect hop production overseas. Protecting this enviable status should be an absolute priority since their import could cost growers millions in lost production, unacceptable brewing quality, control and containment programs. While federal, state and territory governments are responsible for all pre and post-border biosecurity measures, their personnel are generalists rather than experts. This means onus is on the hop industry to manage any risks associated with the import of hop propagation material. We need to work together to ensure all growers abide by the import conditions, know the key threats, remain vigilant and report suspected incursions.

Despite the fact there are prescribed pre and post-border biosecurity measures in place, it’s very difficult to import hop propagation material safely, even when the import conditions are followed to the letter. The import conditions for hop propagation material are available on the Biosecurity Import Conditions (BICON) system, and include a valid permit, virus-free certification, establishment and disease screening at a government owned quarantine facility. Failure to abide by these import conditions exposes all stakeholders in the hop industry to high levels of risk and may result in a hefty fine or even jail time.

The Australian hop industry is fortunate to be free from damaging pests and diseases that affect growers overseas, but two-spotted mites and other arthropod pests do occur. In the case of two-spotted mites biological control is sometimes possible with the resident population of predatory mites, such as Phytoseilis persimillis, and other beneficial insects that are available for purchase and release from Biological Services.

There are currently no antifungals registered or permitted for use on hops anywhere in Australia. The onus is on growers to take all necessary precautions to stop the import of key fungal, viral and viroid pathogens in Table 1.

Table 1. Key fungal, viral and viroid pathogens that present a threat to the Australian hop industry

PATHOGEN	SYMPTOMS	OUTCOMES	MANAGEMENT
Citrus Bark Cracking Viroid	Also referred to as severe hop stunt viroid due to its much shorter incubation period. Early season growth is delayed causing the length of internodes to be reduced by as much as two-thirds. The cones on the sparse and shortened laterals are smaller and development is slower. Visible symptoms only take up to one growing season to appear after initial infection.	Caused severe mortality in hops in Slovenia.	Can only be eradicated from the soil by long fallow periods prior to replanting, which would cause major problems since Australia has very limited land available for hop production.
Downy Mildew	Stunted, brittle shoots with downward curling leaves. A distinctive yellowing beginning at the centre of infected leaves may be present before purple to black spores on their underside can be observed.	Caused upheaval in the hop industry in the 1990s. Can result in severe crop damage, and in some cases complete crop failure if significant infection and crown rot occurs.	Infected bines must be manually removed and healthy shoots retrained in their place. No single management tactic provides satisfactory control. Strict attention to growth, prudent irrigation management and timely antifungal applications are needed to manage the disease successfully. Some of these antifungals are copper-based, which presents a major threat as it can inhibit the development of fruit-forward flavours that are characteristic of Australian varieties. Copper is also one of the most widely reported heavy metal soil polutants
Hop Stunt Viroid	Early season growth is delayed causing the length of internodes to be reduced by as much as two-thirds. The cones on the sparse and shortened laterals are smaller and development is slower. Visible symptoms may take three to five growing seasons to appear after initial infection, which frequently leads to propagation and planting of infected material.	Caused severe mortality of hops in Japan, Europe and North America. Can reduce alpha acid yield by 60-80%.	Any infected bines should be removed promptly, including as much root tissue as possible. Because of the latent period, several adjacent plants should also be removed. Sites should be allowed to remain fallow for one season so that any remaining living roots produce shoots that can be treated with herbicide. Farm equipment should also be thoroughly sanitised to remove plant residue that may lead to further transmission.
Mosaic Viroid	Mosaic mottling between major leaf veins that can become necrotic. This is most severe when a period of cool weather is directly followed by a period of high temperatures. Plants can be infected for several seasons without visible symptoms until the appropriate environmental conditions occur.	Infected plants may establish poorly, exhibit weak bines, and often fail to attach to the string. Varieties with Golding ancestry are particularly susceptible, and yield can be reduced by up to 60%.	Use of herbicides rather than mechincal pruning to control basal growth. This may help to reduce transmission to adjacent plants. Application of insecticides to control aphid population may also help to reduce transmission to adjacent plants.
Powdery Mildew	Powdery white masses that develop on stems, leaves, buds and cones. During periods of rapid plant growth, raised blisters are often visible before sporulation can be observed. Infection of burrs can cause abortion or severe distortion as it develops.	Caused upheaval in the hop industry in the 1990s. Can result in severe crop damage, and in some cases complete crop failure due to lost production and unacceptable cone quality. Breeding programs would also experience significant set backs.	Integration of varietal resistance, crop sanitation, fertilization, irrigation and timely application of antifungals throughout the growing season. Some of these antifungals are copper-based, which presents a major threat as it can inhibit the development of fruit-forward flavours that are characteristic of Australian varieties. Copper is also one of the most widely reported heavy metal soil polutants in the world.
Verticillium Wilt	Range and severity vary depending on the aggressiveness of the pathogen. Yellowing of the lower leaves, death of tissue between major veins, and upward curling are common. Infected bines become noticeably swollen and tissue exhibits medium to dark brown discoloration when the plants near flowering.	Caused significant damage in Europe. Plants affected by non-lethal strains in one season may fully recover and appear healthy the following season. In contrast, plants affected by lethal strains will experience a sudden collapse of leaves and laterals that will rapidly kill susceptible varieties.	Can only be completely eradicated from the soil by long fallow periods prior to replanting, which would cause major problems since Australia has very limited land available for hop production.

Australian growers don’t need to look very far for examples of just how devastating the invasion of these key fungal, viral and viroid pathogens could be for the hop industry, particularly because their absence up until this point means that any varieties developed in Australia are possibly susceptible to an outbreak. For instance, it took 5 years and more than $26 million for the Australian banana industry to eradicate Banana Freckle in Cavendish Bananas. Similarly, it took 6 years and more than $1 billion for the New Zeland kiwi fruit industry to recover from Bacterial Canker infecting Golden Kiwi Fruit.

The primary means of importing the key fungal, viral and viroid pathogens is through infected hop plants, from which subsequent propagation can and does occur. If you’re seeking hop propagation material to grow on your farm, at your brewery, or in your backyard, be sure to use a reputable Australian supplier. In other countries, growers have developed programs like the National Clean Plant Network. There is currently no such program in Australia, so propagation should only be made from parent plants that are known to have good growth, yield and are free from pests and disease symptoms. Growers should discuss plant health status with their supplier, inspect parent plants in field, and access plant pathology services through their local Department of Primary Industries (DPI). If you can’t source the hop propagation material you need from an Australian supplier, it is essential that you import certified virus-free material while abiding by the strict import conditions.

Digital resources are also becoming increasingly important to plant biosecurity, providing fast access, download and analysis of information. See Table 2 for some of the online systems are used by stakeholders in the biosecurity system.

Table 2. Digital resources that aid plant biosecurity in Australia

RESOURCE	ORGANISATION	INFORMATION
Australian Biosecurity Import Conditions (BICON) for hop seed, hop tissue culture and hop nursery stock	Department of Agriculture, Water and Environment (DAWE)	• Import conditions • Fact sheets • Contingency plans • Diagnostic protocols
The Biosecurity Portal	Plant Health Australia (PHA)	• National plant surveillance reporting tool • Knowledge bases and data libraries • Shared spaces for committees and working groups • Awareness and information resources
The Australian Plant Pest Database (APPD)	Plant Health Australia (PHA)	• Key reference system for plant pests and diseases • Information on validated pests and diseases of plants with significance to agriculture, forestry, pasture or the environment • Draws information from 18 databases throughout Australia
AUSPestCheck	Plant Health Australia (PHA)	• Surveillance data on the presence or absence of exotic and established pests around Australia • Maps generated in real time provide digital representation of pest status around the country, including during invasions

While the Australian Government is responsible for the majority of pre and post-border biosecurity measures, state and territory governments are responsible for the delivery of plant biosecurity operations and supporting legislation within their borders. Each state and territory has a different approach to preventing the spread of existing and exotic pests and diseases, primarily due to the varied climatic conditions and legislative frameworks across the country. See Table 3 for details regarding the department that is responsible for plant biosecurity in your state or territory.

Table 3. State and territory government departments responsible for plant biosecurity

STATE OR TERRITORY	DEPARTMENT
ACT	Environment Planning and Sustainable Development (EPSD) Directorate
NSW	Department of Primary Industries (DPI)
NT	Department of Primary Industry and Resources (DPIR)
QLD	Department of Agriculture and Fisheries (DAF)
SA	Department of Primary Industries and Regions (DPIR)
TAS	Department of Primary Industries, Parks, Water and Environment (DPIPWE)
VIC	Department of Jobs, Precincts and Regions (DJPR)
WA	Department of Primary Industries and Regional Development (DPIRD)

It’s critically important that anyone who is not prepared to invest the time, money and effort required to abide by the import conditions simply make do with the hop propagation material available in Australia. It’s time to work together to ensure all growers abide by the import conditions, know the key threats, remain vigilant and report suspected incursions that could threaten hop production, the brewing industry, and a future full off delicious hop-forward beers.

Interpreting hop certificates of analysis

Pixel3 — Thu, 04 Feb 2021 12:37:32 +0000

Understanding hop analysis is key to producing beer of consistent quality. Hops are a natural ingredient produced by a highly specialised horticultural system in temperate regions around the world, which means they are subject to seasonal and lot-by-lot variations. Hop analysis gives brewers the opportunity to optimise their process to achieve consistency and efficiency.

This information is intended to be a high-level practical introduction to interpreting hop analyses, and their relationship with brewing performance and beer quality. It will not explore the hop production process or how these parameters are controlled by the hop suppliers.

Hop requirements in the brewery

The basic attributes of hops should meet the following requirements:

Normal colour, specifications, flavour and aroma
Intact and appropriate packaging and product type
Accurate labelling as to variety, origin, production date and bittering potential
Free from contamination and safe for use in beer production

Product types

Hop suppliers typically provide certificates of analysis (CoAs) for dried whole hop cones or hop pellets, but they can also provide CoAs for alternate product types upon request. For instance, green hops are available during harvest, have a very short-shelf life, and typically make up a minor component of the annual hop requirement for a brewery.

Dried whole hop cones are the most natural, unprocessed product type, and can be used to form a filter bed when straining the boiled wort or dry hopping. They are picked, dried and pressed into bales, which can be broken down into smaller, vacuum sealed quantities.

Hop pellets are dried whole hop cones that have been milled into powder and pressed through a pellet die. Different milling technology allows for the production of various pellet types. The most common are T90 (standard), T45 (lupulin enriched) and pre-isomerised.

Certificates of analysis and specifications

Brewers can use CoAs to anticipate process changes required to achieve consistent brewing results, and to verify compliance with hop specifications.

Most product types will be supplied in sealed, oxygen barrier laminated foils that have been back-flushed with inert gas (carbon dioxide or nitrogen) and packed in cardboard cartons.

As a minimum, each carton should be labelled with variety, producer, crop year, production date, batch identification numbers, product type, net weight and bittering potential (alpha acid contents and analysis method). There is no standardisation of CoA information. In their most basic form a CoA will cover the same information as the carton labels, but some more detailed CoAs may include additional information such as essential oil content, moisture content or agricultural chemical residue reporting.

Typical hop analyses and their significance

Drivers of variability in analytical hop quality outcomes

Accuracy and inter-laboratory error in hop analysis

When assessing compliance with hop specifications, it is important to note many of the methods published by European Brewery Convention (EBC) and American Society of Brewing Chemists (ASBC) for measuring the above analytes have high standard deviations and inter-laboratory error. The ASBC run an international check sample service that is focused on the analysis of bitter acids using titration, spectrophotometry and high performance liquid chromatography (HPLC). There are currently no inter-laboratory comparisons made for determination of moisture content, oil content or essential oil profiles.

Food safety issues

Hops that are used in brewing are a food ingredient. This means producers are required to ensure all typical food safety requirements are met. Suppliers should be able to provide allergen and residue statements.

Beyond CoAs

Hop CoAs and label information describe the hops at the time of packaging. Chemical changes that affect performance in beer may occur if the hops are transported, stored and/or handled improperly at any stage of the supply chain.