wa·ter – /ˈwôdər,ˈwädər/ – noun
You may remember a Kräftig television commercial from a few years back, starring some crudely animated fellows singing about the Reinheitsgebot, the now 500 year old German beer purity law. That law states that all German beers are to include three ingredients, and three ingredients only: Malted barley, hops, and water (yeast being an implied fourth ingredient). All of these (yeast included!) are fascinating ingredients that deserve the thoughtful consideration of every brewer, but which fall outside the scope of this here article.
I’m here today to talk about water. Or, to put it another way, a full 33% of the total ingredients used in beer making, according to the Reinheitsgebot. To put an even finer point on it, water makes up over 90% of the composition of every finished beer. In short, no self-respecting brewer would give short shrift to an ingredient that plays such a major role in the beer he or she works so hard to craft.
Before we go any further, raise your hand if you are an extract brewer. If you did not raise your hand, please stand by. Extract brewers: for you, the recommendation is to use either distilled water which is available at your local drug or grocery store, or reverse osmosis (RO) water which is commonly available at your grocery store water machine to brew with. This is because of the way in which extract is produced. The facility that produces the extract conducts a mash and lauter, just as any all grain brewery does, then concentrates the wort into either a syrup called liquid malt extract or a powder called dry malt extract. The water used in the process contains all of the necessary minerals, so any minerals present in the water you brew with are added on top of the minerals already present in the extract. Using distilled or RO water (herein referred to as RO for simplicity’s sake) ensures that you do not significantly alter the mineral content of the finished beer. Distilled water contains zero total dissolved solids (TDS; zero being obviously really damned low), while RO water typically contains between 15 and 30 parts-per-million TDS (only slightly less really damned low). Pretty easy, eh? Cheers, extract brewers!
Okay, all-grainers. Yours is a tougher road to hoe, I’m afraid. But hey, chin up. We’ll get there. You have basically three choices, and the path you choose to walk greatly depends on your existing water, and the goal for each beer. There really is no wrong or right here, and I personally practice all three throughout the brewing calendar. For example, if I want to brew a beer like Pilsner Urquell, using 100% RO will give me a good, soft base with low mineral content appropriate for the style. At the other extreme, a beer like Guinness draught requires a moderate-to-high carbonate content in order to balance the high acidity contributed by the large quantity of roasted barley in the beer. But I digress…
Brew with your existing water as-is: Most municipal water sources in the St. Louis metro area are of excellent quality, with a moderate mineral content suitable for most styles. That’s the good news. One the other side of this particular coin are the chlorine and chloramines used to disinfect your drinking water. If allowed into your wort, these will lead to the creation of chlorophenols (plastic-like, medicinal flavors) in the finished beer. Ah, but more good news! Using a charcoal filter will reduce these compounds to negligible amounts.
A cautionary note for those on well water: some well water contains high levels of iron, making it unsuitable for brewing. If this is the case with your water, it is recommended to use RO or bottled water.
Modify your existing water: This method provides a lot of flexibility. You can add brewing salts to adjust mash pH or push desired flavor perceptions, or you can dilute with RO to lower mineral content. It’s as easy as it sounds while being as difficult as you want to make it.
Use RO and “build” your water profile: This approach gives a brewer the most freedom to create, the most control over the finished product, and is an advanced technique beyond the scope of this article.
Understanding the basics of what minerals are present in your brewing water (and how to adjust them) can take your beer to the next level. We’ve only scratched the surface in this article, but my hope is that the information presented here has piqued your interest enough to spur further reading on the subject. Cheers to you, home brewer!
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