On Saturday 26th April 2025 some members of Anglian Craft Brewers headed for CPL Aromas in Bishops Stortford. Our host for the day was ACBs Alan Osbiston. Alan hosted a similar sensory day in 2019 so we convinced him to run it again before he retires from CPL and this group was a good mix of those who visited before and those that where here for the first time.

Alan introduced us to CPL and gave us some background about the science and studies into the sense of smell. We sat a smelling test that consisted of 8 triangle aroma tests where we had to identify if all 3 smells were the same, all 3 different or if one was unique. For each triangle we were also tasked with identifying the smell group – for example floral or spicy. Finally we were given one smell at different concentrations and asked to put them in order of strongest to weakest aroma. This test is used by the company during recruitment with a pass mark of 14 correct answers (Alan did mention that he got them all correct back in the 80s!). I think only one of us managed to get more than 14 but it was interesting that some were stronger at spotting similarities and differences whereas others could identify the aroma group.

With pizza finally ordered we had a look around the CPL facility until it arrived. Anything with an aroma was present in the offices from toilet clearer to expensive perfumes and everything in between. The labs all have special air conditioning that isolates and scrubs the aromas, some have dedicated smelling booths, others simulated bathrooms, as well as instrumentation for analysis, head space analysis, a laundry room and formulation labs.

Alan kindly provided some of his homebrew which we enjoyed as we ate the pizza, and throughout the rest of the day. There were also beers provided by some of the attendees and a Caramel Cookie Chocolate Stout by Vocation – this has lots of non-beer like aroma…

In the afternoon, the focus was on aromachemicals found in the brewing process and finished beer. Alan broke the process down into Mash, Fermentation, Conditioning and Hops and along the way we smelled some associated aromas. From the aromas found in off beer, through esters and phenols we sampled them all, ending with the pleasant aromas derived from hops.

What a fascinating and informative day, thanks to Alan for inviting us to CPL Aromas, for sharing his knowledge of aromachemicals and applying it to the brewing process.