It was our first main bit of equipment to arrive and although relatively small compared to the rest of our kit, it will help us take a huge step forward in terms of the quality of our beers. The precious cargo I’m talking about is a centrifuge, sent to us all the way from Sweden by beer separator experts, Alfa Laval.
When beer is brewed, one of the by-products is yeast particulates. Historically, brewers relied on gravity to separate out the yeast, which over time will settle into the conical base of the fermentation vessel. To speed up beer production, modern breweries used filters to take out the unwanted yeast and achieve a higher level of clarity in their beers. The problem with this approach is that aromatic and flavoursome hop oils introduced by dry hopping cling onto the yeast and get filtered out along with it. Filtering also introduces oxygen, a brewer’s nemesis, which leads to quicker degradation of flavour. Lower oxygen levels in the beer deliver a fresher, tastier product with an improved shelf life.
The centrifuge separator works by pumping the beer around a cylinder at speeds of 5000rpm or more. This generates a centrifugal force which pushes the heavy solid matter to the perimeter, enabling it to be removed. Using a centrifuge instead of a filter allows us to separate out and keep those highly coveted hop oils, whilst removing the unwanted yeast.
Having used an Alfa Laval centrifuge at his previous brewery, Our Head Brewer Matt is experienced in the benefits they offer;
“Why a centrifuge? There are many conventional ways to clarify beer, everything from letting time and gravity do its work, sheet filters through to diatomaceous earth filters. We selected a centrifuge because it will clarify beer without passing it through filter media which could potentially damage the aroma of the beer. There is also very little oxygen uptake with a centrifuge. We chose to work with Alfa Laval in part because of my experience running one of their separators, but also because of their world class reputation for quality.”
We can’t wait to rig it up and get it running. We’re particularly looking forward to dialling in the clarity of our beers to a specific turbidity and experimenting with the differences in aroma and flavour this fine tuning enables.
Joseph
Founder, Gweilo Beer
