The history of brewing goes back millennia but the principles are the same now as they would have been for our ancestors which is why we teamed up with The Institute of Making to hold a workshop (or should that be workHOP) on brewing. Biochemical Engineering is, at its most fundamental, the use of cells – be they mammalian, bacterial or fungal – to convert a product we have into another one that we want more. Today we often think of the manufacture antibiotics, biofuels or vaccines, but the oldest example of biochemical engineering is using yeast, a single-cell fungus, to change the sugars in grain into beer.
We are very grateful to James Goodman of Howling Hops for his masterclass on Monday 18th July, together with our own James Lawrence and Mike Sulu from The Department of Biochemical Engineering. We were given a brief history of brewing, how beer was could be the only safe liquid to drink as brewing sterilised the drink and water supplies were contaminated for much of human history (regular beer facts provided by The Institute of Making’s Ellie Doney). Did you know that beer was one of the only products not rationed during the second world war?
James Godman runs a commercial brewery but is also a keen home-brewer and gave us some useful advice to make our own beer as the same process takes place in a kitchen or a factory. We were first given the chance to smell and taste some malt, these are grains of barley that have been allowed to begin the process of germination and then baked dry once they’ve just started making sugars, this gives them their distinctive flavour (which you can also enjoy in many products such as chocolates or bread), we also looked at other grains that are added to give the beer different textures or flavours, as well as hops - leaves that help sterilise the beer and add tasty bitterness.
The UCL Department of Biochemical Engineering has a small-scale brewery that can make up to 120 litres of beer, which you can see here. Once the water in the top vat had reached 70 degrees it was added to a bag of malted barley, together with a small amount of other grains for the recipe, then stirred and left for the sugars to dissolve into the water, a mixture called the mash. In the nearby Petrie Museum there is evidence of brewery going back millennia, but they would allow the mash to ferment and then suck the beer out with a straw from a communal bowl.
The mash was then filtered and the resulting liquid, which looked much like beer, was heated to boiling point to sterilise it before it was cooled down quickly with a heat exchange and put in a vat with some yeast to start its two-week journey to becoming beer. We also measured its mass and calculated that the resulting beer will be around 4.2% ABV - this is a requirement of the HMRC licence needed to brew beer (none is needed for home brewing for consumption at home, but we have a special license that allows staff to taste this experimental batch). In a week’s time we will come back and decant it into casks for it to complete it’s transformation.
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Ellie, James (UCL), Mike and James (Howling Hops) introducing the workshop
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Hops, grains and recipes for beer
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Malted barley is very tasty, as well as being essential for making beer!
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Different grains make different beers
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Mixing malted barley with hot water to release the sugars
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Checking the temperature of the mash (water and malted barley mix)
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Adding the yeast to the cooled, filtered raw beer to start the brewing process
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Measuring the density of the beer to be able to calculate its alcohol content
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