The secrets of beer

Like cooking, brewing beer can be considered an art, or a series of chemical reactions. Far from being in opposition, these two aspects are combined by the brewers: they play with science to produce beers of better quality, avoid excessive variations in taste, or on the contrary explore new palettes of flavors.

Chloe Bourquin
special collaboration

Cereals, water, yeasts and hops. The ingredients for the beer recipe seem quite simple at first glance. “But for it to taste like beer and look like beer, each ingredient must be chosen carefully,” says Mario Jolicoeur, professor in the chemical engineering department at Polytechnique Montréal, who teaches an engineering course there. brewing for almost 10 years.

For example, water contains certain minerals that influence the chemical reactions that take place during brewing. There is also a wide variety of cereals that can be used (barley, wheat, oats, etc.), the germination of which is stopped at a more or less early stage, to give different malts. “We can play on the humidity and the temperature of the drying of the malt to go from a very pale grain to a roasted grain, with shades of chocolate, coffee…”, illustrates Mario Jolicoeur.

What about hops? “We add it at the beginning or at the end of boiling to play on the bitterness, but also to give a floral or vegetal character. In this way, the properties of the beer are built by adding flavours”, specifies the professor. Essential to fermentation, yeasts also make it possible to develop particular aromas. “We can use several yeasts, even certain bacteria to produce lactic acid and acidify the beer; this is particularly the case for sour beers,” explains Mario Jolicœur.

Rigorous quality control

Once the ingredients have been selected, we get to the heart of the matter: brewing. It is then a question of proceeding with rigor. “A small mistake at the beginning of the process can lead to a very big deviation in taste at the end,” emphasizes Mario Jolicoeur.

To avoid such a situation, “we check the temperature and the duration of each step, as well as the acidity and the density of the liquid, in order to predict in particular what the final alcohol percentage will be”, explains Mike Doucette, researcher at the within the Applied Research and Innovation Network of the New Brunswick Community College.

Some microbreweries call on external laboratories, such as that of Mike Doucette, to support them in setting up a new recipe or in adopting good practices. Others have chosen to push the scientific aspect further: the microbrewery Grimross, established in New Brunswick, has for example set up a laboratory on its premises, in order to test samples of beers produced there every week.

“We check the alcohol level, carbonation and oxygen levels, bitterness, color, clarity…”, lists Devin Kearney, quality control technician at Grimross. “We want to make sure customers have the same experience every time they open one of our beers. »

A scientific and gustatory playground

It is also possible to play with all this underlying science to innovate and explore new palettes of flavors. “In small craft breweries, we try to surprise the consumer. Chemists then try to determine which compound is responsible for this or that flavor, and advise brewers to continually invent new recipes,” says Professor Dale Wood. The latter set up a certificate in brewing sciences at Bishop’s University, in Sherbrooke, to train a dozen students each year in the ingredients, processes and analysis methods specific to the brewing of beer.

“When you use the right ingredients and do it right, it becomes hard to miss a beer. If a beer is not bad, it will find its audience, because there are always people who like beers that are out of the ordinary, whether they are very bitter, very floral, or even tasteless. nothing at all,” smiles Mario Jolicoeur.

Towards a 100% local beer?

Researchers are also helping brewers replace certain ingredients imported from the West with malt or hops grown in Quebec, to move towards a 100% local beer.

Upstream, Quebec producers work with scientists to meet the needs of breweries. “We don’t have the same climate or the same type of soil in Quebec as on the West Coast, so hops, for example, can taste different if grown here,” says Dale Wood. “We can then carry out analyzes and advise producers on minerals to add to their soil. »

Each microbrewery has its own recipes, its know-how, but also its own ingredients (local or imported), which explains the great diversity of Quebec beers. “I often encourage people to travel across Quebec and go to small towns to sample local beers. This is where you find really unique and interesting products,” says the professor.

Chloé Bourquin, author of the article and freelance journalist at The Press, is a doctoral student at Polytechnique Montréal. She has no connection or affiliation with Mario Jolicoeur, a professor at Polytechnique Montréal cited in this article.