A pint of clear
So much beer talk concerns the malts, hops and other adjuncts that go into making a fine brew.
These ingredients are essential to delicious beverages, but the most obvious beer ingredient is hiding in plain sight — water.
Humble H2O generally accounts for at least 90% of a beer’s volume. It is an essential ingredient in our beloved ales, lagers, stouts and sours.
As anyone who has ever found hard white residue in their kettle will know, water is not just a string of hydrogen and oxygen molecules.
It is a chemical with an incredible ability to dissolve other chemicals, and because of this trait, the composition of the water used in brewing affects the brewing process and the final beer produced. The type of water you have will also influence the range of beers that it will brew the best.
Historically, various regions’ or countries’ deserved reputations for certain beers can be traced back to the chemical composition of the water being used to brew their style of beer.
It has long been said that the secret to the unique taste of Dublin stouts and porters was the water that was used to originally brew them.
Dublin water was known to be rich in bicarbonate with low levels of sodium — the perfect blend to enhance the bitter qualities in the brew which balanced the beer’s malty characteristics, resulting in a world-famous stout.
The town of Plzen, the birth place of the iconic beer pilsner, was blessed with remarkably soft, alkaline water, which ensured the optimum pH level in the mash could be achieved, giving way to a beer replete with soft, rich, bread-like flavours and a mellow hop bitterness with pronounced hop aroma. This created a beer whose popularity swept Europe and the world.
Water, and more precisely six main ions in the water, dictate the pH level which influences the efficiency of the brewing process.
Water also affects the beer’s mouth feel and can alter the perceived bitterness of a beer, which has a knock-on effect on the hops required to make it.
As it is largest single component in finished beer, water also directly adds flavour to the beer itself.
Today, brewers can control the chemical composition of the water they use for brewing, enabling a large variety of beer styles to be brewed anywhere in the world.
Water is often de-ionized to remove unwanted calcium, sodium, chloride, sulphate, magnesium ions and various carbonate ions.
The water then can be adjusted by adding specific amounts of these ions in salt form, to get the desired water recipe which will result in the beer style the brewers wish to brew.
This makes the brewing process more predictable, and enables brewers to brew styles of beer that don’t depend on the composition of their water source.
Considering the role that water plays in making great beer, maybe the latest Guinness ad campaign encouraging people to drink Guinness ‘clear’, a form of H2O readily available on tap, is not far off the mark!
Judith Boyle is a qualified chemist (MSc) and accredited beer sommelier. Susan Boyle is a playwright, artist and drinks consultant. See www.awinegoosechase.com. Both sisters are proud to be fifth-generation publicans. Their family business is Boyle’s bar and off-licence in Kildare town