THOUGHT PIECE the carling team
Another Key Ingredient In Brewing – Water – Part 2
Last month we considered the importance in brewing of the calcium and bicarbonate ion, of course there are other ions of significance in the water. Sulphate promotes crispness and accentuates hop bitterness but it can be overdone leading to sulphidic notes as in the famous ‘Burton snatch’. Chloride on the other hand provides fullness, so the ratio between the two is critical. The SO4:Cl ratio in ales might be 2.5:1 while stouts may be 1:3 and milds in between at 1:2.
A new head on an old bore hole. Note the volume meter and there will also be a conductivity meter to alarm if the salt levels change.
Beware also that increasing levels of sodium can be salty and metallic; potassium is soapy while magnesium is very astringent and has aperient properties (as in Epsom salts). Iron gives an inky taste while nitrate can be reduced to nitrites and on to nitrosamines which can be carcinogenic.
Where do brewers get their water from? The public supply is not the cheapest option and the water only has to be potable so may not have the levels of ions suitable for brewing unless it is further treated. There is also no obligation to tell brewers if the source moves, boreholes are likely to have higher dissolved solids than a reservoir. The incoming water will be chlorinated and chlorine can react with various organic compounds in malt to yield phenolic flavours. Chlorine and taints from rotting vegetation in shallow reservoirs can be removed by passing water through an activated carbon filter.
Carbon filters will remove chlorine and taints from incoming water.
Many established breweries have their own wells and boreholes. Water can be pumped considerable distances often from the old family farm lands to the brewery in the town. With many family breweries downsizing and moving premises, some boast that the new location is on the same aquifer so customers should not be alarmed that the beer would taste different. We have seen that since the nineteenth century that you can in fact brew any style of beer anywhere you want.
Many have resurrected old bores on the brewery premises to increase wash water supplies as town prices inexorably rise. Shallow sources give more problems as you cannot stop farmers in the catchment area grazing animals or using nitrate fertilisers unless you own the freehold.
Robinsons in Stockport boast that its bore is as deep as the Blackpool Tower is high (518 feet or 158m). So deep is better but more expensive in maintenance, You need to keep the twenty first century out by a sheath down at least the first 20 m or so. The Environmental Agency will grant an abstraction licence with maximum and total allowed flows. Treatment might include carbon filtration, UV sterilisation, aeration and filter to remove iron and manganese. Chlorine dioxide is often injected if the brewery pipework is extensive. Water is thus a lot cheaper but whether you use your own bore or towns supply you have to pay effluent charges on any volume that eventually goes down the drain.
Deaerated water for beer dilution is made by bubbling nitrogen through a packed column to remove oxygen. This one is by KHS.
Washing wooden hogsheads in the scalding sheds used a lot of water as did old bottle washers and a ratio of 15hL water to one hL brewed would have been typical a few decades ago. Today all breweries should easily achieve seven and most should aim for four but it does depend on the package mix. Effluent costs and environmental awareness means modern plants will be around two.
Brew water is not suitable for all applications in the brewery. Boiler feed needs low solids and water is added to high gravity beer after filtration. If a standard lager is brewed, fermented and conditioned at 7%ABV but is sold at 4%ABV each 100hL at high gravity needs the addition of 75hL of water which must be sterile and free of oxygen which could lead to staling in package.
If you are brewing more lagers or even different craft styles it is better remove all ions by reverse osmosis or ion exchange resins. It amuses me that the Molson Coors brewery in Burton now burtonises its water when brewing the odd ale. Reverse osmosis uses a large pump to force water molecules through a semi permeable membrane leaving the salts behind. The energy costs are high and there is a highly saline residue to dispose of. Ion exchange is older technology where the columns need regular regeneration so that a duplex system is essential if you want to keep going 24/7.
Ultrafiltration units will remove microorganisms from treated waste water.
Can brewers reuse water? Ultrafiltration will produce a pure water which could be used for mashing and is often better quality than that incoming from the town’s supply but there is always the threat of adverse publicity. Waste from bathrooms etc will always go to the town sewer and always has.
In 2017 Stone Brewing in San Diego tackled this challenge faced by the brewing industry head on. Its Full Circle beer was brewed with 100% recycled water from the city’s waste water treatment plant. A lot of brewers recover water but always say it is only used for washing down and never brewing even when the quality of incoming water is inferior to the liquor they have treated themselves! San Diego is planning to use a third recycled water by 2035, which in drought strickened California seems a tad conservative. The brewery could probably have done without the ‘toilet to tap’ and ‘sewer beer’ headlines! They quickly retrenched pointing out the beer was only available at a pure water event for a single day.
Heineken devised its Brew a Better World (BaBW) plan which has driven innovation and collaboration to protect the environment, support local communities and make a positive contribution to society – all with the goal of supporting delivery of the UN Sustainable Development Goals. Heineken is aiming for carbon neutrality by 2040 at its 160 breweries worldwide and says that 30 of them currently brew in water scarce areas where it aims to help replenish the watershed area by reversing deforestation. The UN reckons that two thirds of the world’s population may face water shortages by 2025 and that is only three years away!