Oakham Ales – Controlling Bitterness and Aroma Through Analysis

Oakham Ales is a multi-award winning brewery with a worldwide reputation for its innovative approach and for the quality and consistency of its brews.

Famous as the first UK brewery to brew a beer with 100% US sourced Citra® hops, hop forward beers are a core part of the brewery’s range. Unique bitterness and aroma profiles are created by layering hop additions throughout the brewing process with 3 additions in the copper, 1 in hopback, a hop ‘tea’ infusion and another in conditioning, making 6 additions in total.

At Oakham Ales, bitterness has traditionally been monitored by aroma and flavour, not by analysis. Head Brewer Mark Tetlow and Quality Assurance Brewer Stewart Poulter wanted to measure bitterness more accurately and chose the CDR BeerLab supplied by QCL, due to its accuracy, ease of use, speed of test, and the non-hazardous reagents used compared to the reference method.

After initial training from QCL and validation with the ILCS proficiency scheme, Stewart started by testing packaged beer to give a benchmark IBU for the finished beer, then tested various stages of the brewing process to determine bitterness development and establish hop utilisation.

“For our size of brewery, the CDR BeerLab® is an ideal tool for QA and process control. It is very easy to use, without needing a lab background and the reagents are non-toxic so it’s easy to implement” Stewart Poulter

The analysis showed that bitterness developed in the 3rd hop addition did not contribute to the final bitterness of the beer as it was likely removed by the yeast during fermentation. The later hop additions allowed Oakham to achieve the final in package bitterness required. There was also an added benefit of the later cold additions contributing more aroma to the beer.

he CDR BeerLab® has become an integral part of the QA program at Oakham, contributing to optimisation of the brewing process and helping to maintain the brewery’s reputation for consistent, high-quality beers.

“Understanding the bitterness process and hopping regime has allowed us to streamline the brewing process to extract maximum aroma from the hops whilst maintaining the correct bitterness levels. By changing how and when we added the hops we kept more aroma in the beer and less going up the chimney!“ Mark Tetlow.

  Beer 1 Beer 2
  15.8 27.3
  15 26.3
  16.3 27.5
Mean 15.7 27
SD 0.66 0.64

 

Graph 1: CDR BeerLab® Bitterness compared with reference method at Campden BRI

Graph 2: IBU Development of a brew