In New Zealand, Hop Revolution’s Processing Is Built for Highest Quality

Providing craft brewers with a consistent supply of premium hops requires a group of like-minded experts, problem solvers, and considerable manpower. While growing healthy, vigorous hop plants is the obvious first part of the equation, the field team’s yearlong efforts lead up to four weeks of intense harvesting and processing in New Zealand’s Nelson Tasman region. Having a processing facility that delivers reliably in a time-sensitive environment is a crucial cog in producing a top-quality product.

The Team

After two successful harvests completed at Hop Revolution’s first hop garden, Tapawera, it was time to turn attention to their new Wairua Hop Garden. Quality through innovation is in Hop Revolution’s DNA, and construction of the 3,500-sqm processing facility would be guided by the same philosophy. To this end, a team of local and international experts were brought together by Hop Revolution Engineering Manager, Glen Stebbings and Operations Manager, Jono Trolove, to incorporate original thinking through every stage of the development. Last August the Nelson-based management team of CWG alongside the New Zealand construction engineering firm Calder Stewart, were called on for their expertise and experience in realising projects of this large scale.

Picking

When deciding what type of processing facility would suit Wairua, the top factors considered were reliability, availability, quality, and capacity. Harvesting windows are exceptionally short, and once the bines are delivered to the facility, picking time and efficiency is of the essence. Enter Keith Upson and the team at Upson Engineering. Over the last decade, this local Nelson engineering firm have developed a modern, large-capacity picker based on the Dauenhauer concept, with vast improvements such as the new magazine and pre-loader systems.

The Upson machine is a triple-bank main picker with three cleaning lines. It is fitted out with the patented hook magazine and picker preloading system capable of preloading the machine with up to 15 ton of bines. This means processing can continue even during mechanical failure. At up to 3,600 bines per hour, this machine provides a lot of flexibility to accommodate picking windows.

Drying

Picking is followed by drying and conditioning, and the WOLF three-tier drying system was chosen for its precision German engineering. The system consists of three silos, three kilns, and eight conditioning boxes with two rolling floors. The team made up of local contractors along with Phil Templer and Craig Gosling from Tasman Engineering commenced the kilning and conditioning installation at the beginning of August 2021.

Once picked and waste material is removed, hops cones are kept in the silos until they are required in the kiln. WOLF green hops silos are made of hot-dip galvanized sheet steel and is fed directly from the picking machine. The silo floor is a rolling floor, consisting of overlapping lamellae making a closed surface. This system prevents the hops from touching the ground during transport. In combination with WOLF conveyor belts, the silos are an enormously time-saving requirement due to automatic feeding of the self-monitoring silos.

Modern technology incorporated in the hop-drying process further saves power and time. The WOLF PowerHeaters© are equipped with aerodynamic high-performance fans, distinguished by their stable performance curve and energy-minimized driving power. The air volume is adjusted and regulated precisely as required. As the hops are dried in three smaller layers, and mixed as they move through the kiln, the drying is very even and consistent. Each kiln can produce 200 kg (440 lb) of dried hops per hour, ready to be transferred for conditioning.

The WOLF conditioning system has two advantages: Product is kept off the floor, and moisture levels can be adjusted using the CONAQUA© system. This ensures even conditioning and optimal moisture levels. Each conditioning box holds 10 dried trays ready for conditioning. The optimal air for conditioning is produced by controlling the louver flap servo-motors of the mixed air chamber. If there is too little humidity in supply air, the mixed air is enriched as required by the honeycomb humidifier and a freshwater cascade. An integrated air filter protects the humidifier from contamination, further increasing hop quality. The quality of the conditioned hops can be seen clearly by their gloss and colour intensity.

Baling

The innovation continues with how baling is managed. Hop Revolution’s presses are built locally by Brad Matthewson of Real Steel Engineering. Because hose failures can be catastrophic, Brad has developed a rack-and-pinion style press that avoids having hydraulics near the finished product. This new system is also a lot faster, ensuring bales are delivered quickly and in optimal condition, ready for pelletization, prior to being shipped to craft brewers around the world.

Harvest 2022

Hop Revolution’s state-of-the-art Wairua processing facility’s first harvest kicks off February 2022. By improving every step in the journey from field to bale, their project team ensured that quality and consistency of hop production continues on their Wairua Hop Garden. The unique New Zealand varietals to be harvested and processed from 2022 include Nelson Sauvin™, Motueka™, Riwaka™, Pacific Sunrise™, Kohatu™, and Moutere™.