Black Sheep Brewery is taking advantage of an innovative dry hopping system which is significantly improving the company’s hop yield.
The ROLEC DH is helping the Yorkshire brewer meet a growing trend for hop-forward beers by enhancing flavour and aroma. But savings from lower hop usage mean Black Sheep is on track to achieve return on investment (ROI) within just two years.
Celebrating its 25th anniversary this year, Black Sheep combines traditional brewing processes with the highest quality raw ingredients and, where required, adding a little technological innovation into the mix. This was the case recently when the company identified a growing trend.
Head brewer, Phil Douglas, said: “We noticed that taste preferences were changing, with growing demand for hop-forward ales and craft beers. Malted barley and hops are traditionally raw materials added to beer to balance sweetness and bitterness. Beer that is more balanced toward the hop side is considered hop-forward.
“As a result, many brews now require more and more hops — many of which are new world — to enhance this characteristic.”
As ales and craft beers are the focus of production at Black Sheep, the company wanted to react, at first trialling the manual addition of extra hops to the conditioning tank. However, Black Sheep was approached by The Hoptimiser team at Torqueflow-Sydex in December last year and introduced to the ROLEC DH dry hopper. A short trial of a DH45 model led to its immediate purchase.
Phil said: “The big advantage of the ROLEC DH is that it breaks up the hops, thus introducing greater hop character to the beer. Also, thanks to increased surface area and greater contact with the entire beer volume, we can use less hops to achieve the same hop character. The manufacturer says we can use as little as 40% of a traditional dry hop load.
“While we are not at that level yet, we are certainly using less hops, which of course has a financial benefit. As a result, I estimate we are on course for ROI within 24 months.”
The science
The US-manufactured ROLEC DH allows dry hopping to be performed in a pressurised, closed environment that is purged of air using CO2.
The principle of operation is based on a recirculation pump with a chopping impeller. In effect, the integral SBI pump features blending teeth to increase the surface area of the hops. The unit will chop a typical hop pellet up to four times before it is induced (using differential pressure created by the shear pump) into the beer stream.
Importantly, there is no adverse effect on suspended yeast, head retention or any other aspect of the beer. The pellets are chopped to just the right size so they can settle during the dry hop holding period. This method of dry hopping at ground level is also considered far safer than traditional induction techniques.
Phil said: “Simultaneously to hop induction, the ROLEC DH recirculates the fermenter. Since we were effectively already doing this using a rousing system, we were able to use our existing pipework, meaning our new dry hopper fitted perfectly and easily into place. Recirculation can be done as long as desired, but typically for up to four fermenter turnovers.”
The technology
David Lee, managing director at Torqueflow- Sydex in the UK, has launched the Hoptimiser brand to bring the ROLEC DH to the UK craft brewing industry.
He said: “The DH45 is the smallest dry hopper in the ROLEC series and is designed to ensure that breweries of any size can enjoy the many benefits of efficient and safe dry hopping.”
The 4kW motor-driven system offers a pellet capacity of 20kg and a recirculation rate of 3.4 hectolitres per minute. This fully portable unit comes equipped with pump, VFD, input cord and CO2 regulator. All components are sanitary and CIP-able (no additional CIP pump is required).
The ROLEC DH90 offers 40kg pellet capacity at the same recirculation rate as the DH45, while the largest DH250 can hold 120kg of pellets and, with its larger 7.5kW motor, can deliver recirculation rates up to 4.3 hectolitres per minute.
The results
Black Sheep is using its DH45 predominantly to produce beers such as Pathmaker, an adventurous pale ale with a punchy, tropical aroma and a spiky bitterness. Another beer to benefit is Glug M’Glug, a dark IPA named after a mythical beast that, according to Theakson family folklore, scourged the hills and devoured sheep. Suitably, this ferocious ale combines a complex mix of malts with new-world hops.
Darren Norbury, editor of Beer Today, said: “The hop character in cans of Pathmaker, in particular, is remarkable. There’s a huge hit of grapefruit citrus and some resinous aroma when the can ring is pulled and the beer is a really punchy pale ale, bordering on IPA territory.
“The Glug M’Glug (pictured) is the most beautiful rich mahogany colour and very different to the Pathmaker, being a dark IPA (a new style on me — but I do love black IPAs). Berry fruit dominates the aroma here, but although there’s a big malt bill, the hop notes do shine. Impressive!”
