By Anja van Zyl, head brewer, Hey Joe Brewing Co.
Based in the Cape Winelands, Hey Joe Brewing Co. brews beer locally and meshes foreign traditions with local twists from production, all the way into the hands of the end-user.
With supposed roots going back to Belgium, the brewery dates back t
o the 60s, owned by a fictional character named Joe who had a deep desire to land in Africa and brew the perfect Belgian beer using African inspired ingredients.
To create the perfect brew, they use glycol cooling in different areas for different purposes. An Aermec air-cooled chiller is used to cool glycol to -4°C. The chiller has a cooling capacity of 66.1kW and a water flow rate of 12 629 ℓ/h. It uses a R410A refrigerant.
A stainless-steel tank is also used to store glycol. The tank has a plate in the middle containing a hole in the centre to partially separate the hot and cold glycol. Warm glycol is pumped from the top of the glycol tank to th
e chiller, cooled and pumped back into the bottom section of the tank. Cold glycol at 0°C is pumped to the brewery to where it is required. Warm glycol is pumped back into the top section of the glycol tank.
Glycol cooling
The brewery uses glycol cooling in the following methods:
Wort cooling
Wort is the liquid extracted from the mashing process during the brewing of beer or whisky. Cold water at 4°C is used in a two-phase SPX plate heat exchanger to cool wort from 96-100°C to either 19°C – similar to ale style beers – or to 12°C. The wort is then extracted from malted barley and wheat that are obtained during a process called ‘lautering’. During this process the liquid wort is separated from the spent grain.
The wort is boiled for 60-90 minutes at approximately 100°C. Wort boiling is done to isomerise alpha acids from hops, concentrate wort (water boil-off), sterilise wort, and boil off undesired flavours like dimethylsulphide (DMS).
The wort is cooled within about 80 minutes depending on the batch size at a flowrate of 30-35hℓ/h. This step is vital so that yeast can be added to wort as quickly as possible at its desired temperature at either 10-14°C for lager style beers or 18-24°C for ale style beers.
Cold water cooling
The cold water used to cool wort is cooled by a small two-phase SPX plate heat exchanger. Dependent on the season, water in an 8 000ℓ stainless steel tank is cooled from 18-25°C to 4-6°C. A circulation pump is used to pump water from the tank through the heat exchanger and back into the tank. This pump is also used to pump the cold water to the wort heat exchanger. This water obtains the heat from the wort and gets pumped to a hot water tank at about 70°C. So, the heat energy is not wasted but rather recuperated for hot water usage at a later stage.
Flash pasteuriser cooling
After fermentation and maturation in the CCT (4-6 weeks), beer are either filtered or centrifuge to removed yeast and other solids where after flash pasteurisation takes place. This involves heating beer to 72°C for 30 seconds to inhibit the growth of potential beer spoilage microorganisms. This process prolongs the shelf life of beer. After the heating phase, beer needs to be cooled again before it reaches the bright beer tank (BBT). Ideally cooling to 3°C is sufficient.
Vessel cooling
After wort cooling, yeast starts to ferment the sugars in the wort while it produces CO2, alcohol and heat. Fermentation is an exothermic reaction where heat energy is a by-product of the metabolic process of yeast fermentation. Therefore, cooling is required on the fermentation tanks (also called the conical cylindrical tank – CCT) to regulate the wort/beer temperature for the yeast to ferment optimally. Too high fermentation temperatures can result in off flavours like fusel alcohol that gives a warm sensation when beer is consumed. Too cold temperatures can cause yeast shock and possibly a ‘stuck fermentation’ where the yeast stops fermenting the sugars in the wort. This detrimental to the final product as there will still be residual sugars left in the beer that not only will make the beer taste sweeter, but it could cause re-fermentation in the bottle, can or keg. This could cause the packaged beer to explode.
Cooling is also required for the BBT when force carbonation takes places. The BBT is a temporary holding tank before the beers are packaged. At this stage, the beers are normally carbonated and need to be kept cold at 1-3°C to keep the CO2 in suspension. If not, the beer will lose its carbonation (CO2) and become ‘flat’ again or un-carbonated. To package beer that is carbonated, the beer needs to be cold to prevent foaming at the filling machine. Together with the cold beer, the BBT needs to be pressurised with CO2. The only exception is when beer is packaged un-carbonated with additional sugar and a secondary fermentation yeast for re-fermentation in the bottle. This method is very popular in Belgian style beers.
The project ran from 2018 to 2019. With equipment installation kicking things off in the Brew house. Equipment installed included a mill, water tanks, coolship, keg machine, bottling machine, centrifuge, pasteurizer, fermentation tank, CIP skid, chiller and boiler. Commissioning from the Brew house officially occurred mid-2018, producing the first brew called, ‘Brouer Maak ‘n Plan Belgian Ale’. At the beginning of 2019, the Keg machine and bottling line were commissioned. Official completion happened at the end of February. There were little to no hiccups coupled with the installation. The entire project only experienced a delay of six months, owing to the building inspectors.
The brewhouse has won four world beer awards. With a restaurant adjacent the brewery, the House entertains guests providing all walk-ins a mix of Belgian and South African traditions.
