Interview: graduate gives beer an engineering upgrade

The first sip of a pint is always the best, say some enthusiasts of the amber nectar.

But a lesser-known fact is that one of the key steps in the brewing process can actually diminish its flavour, says chemical engineering graduate, Jack Ramsey.

Beer is thermally pasteurised in order to inactivate yeast and other organisms to increase shelf life, but this process can have a negative effect on the beer’s flavour.

Ramsey was recently presented with the Undergraduate Project Prize by the Institution of Chemical Engineers (IChemE) for his project to improve the pasteurising process of beer to speed up production and improve taste.

It was a bit of a revelation for me discovering that all beer didn’t have to taste the same

Chemical engineering graduate Jack Ramsey

He says he first became interested in craft beer a few years ago after a visit to a craft beer bar in Newcastle.

“It was a bit of a revelation for me discovering that all beer didn’t have to taste the same.

“Since then I have tried to relate as much as I could from my degree to brewing and food and drink processing. Including writing my dissertation on ways that breweries can become more energy efficient and completing a case study on a craft brewery for one of my business modules.”

Loughborough University offers master's students the chance to complete a research project at an overseas university as part of a professional development project.

Under pressure

Ramsey decided to explore the alternative methods of pasteurisation such as high pressure processing (HPP) and thermosonication, a technique that combines heat and ultrasound.

“I came across Filipa Silva’s work at the University of Auckland on non-thermal pasteurisation of beer; the opportunity to try and develop methods to improve the taste of beer really excited me,” says Ramsey.

“I asked her if I could join her research team for a semester and she kindly agreed.”

With the help of university supervisors, Ramsey decided that comparing the inactivation of yeast ascospores in beer as a result of thermal pasteurisation, HPP, and thermosonication, would be very useful.

“To conduct the experiments we first sterilised some beer and then inoculated it with the yeast ascospores,” says Ramsey.

“We then pasteurised the beer using the three different methods at various operating times and conditions.”

By counting the number of yeast ascospores that had survived, the team was able to model the yeast inactivation curves for the three processing methods.

“My research found that HPP and thermosonication could achieve a similar inactivation of yeast as thermal pasteurisation, meaning that they could offer viable alternatives for industry,” he says.

Hopefully breweries that currently employ thermal pasteurisation will consider these alternative techniques meaning that they can distribute better tasting beer

While thermosonication still uses heat to inactivate yeast, it takes less time and lower temperatures to achieve the same inactivation as thermal treatment alone. Ramsey says this indicated it could have a diminished effect on the beer’s taste.

“We also found that unlike thermal pasteurisation, the inactivation curves of yeast by HPP and thermosonication were non-linear. These inactivation curves are vital for the design of pasteurisation systems in industry.”

Looking ahead, Ramsey says HPP appears to have the largest potential as an alternative to thermal pasteurisation of beer.

“Studies have shown that it has a minimal effect on the beer’s taste, and studies like mine have successfully shown that it can increase the shelf life of beer and have modelled the inactivation of yeast that would enable the design of full-scale systems.

“Hopefully breweries that currently employ thermal pasteurisation will consider these alternative techniques meaning that they can distribute better tasting beer.”

Heights to scale

Ramsey says he became interested in studying engineering while doing his A-levels, but didn’t initially know which discipline to choose.

“I was particularly enjoying my chemistry lessons, so I started looking into chemical engineering, and I managed to arrange a tour of a petrochemical plant near my home,” he says.

“I was amazed by the scale of the operation and how these vast plants were producing the raw materials for things that we all use on a day-to-day basis. The way that chemical engineering relates to everyday life, and the broad range of areas that graduates can go into, made up my mind.”

Ramsey has now finished his chemical engineering degree in the UK, and has moved to Edmonton, Canada, where he will pursue opportunities in either the food and drink industry or the field of biotechnology.

“In the long term maybe I’ll open my [own] brewery but I’ve got a lot to learn before then.”