Water Treatment
Q: I've heard that water is very important in all grain brewing. Why?A: Unless your name is Walt, beer is 90-95% water. The content of your water can have a dramatic effect on the taste of the beer you brew. The water that comes out of your tap has a number of ions dissolved in it. Some of these ions affect the flavor of the beer and some of them affect the pH of the mash. Having said that, if your water tastes good out of the tap, then it's almost guaranteed to make some sort of beer. So if you want to just brew with your water and see what happens, I'm not going to fuss at you. But if you want to dig a little deeper, read on...
Q: What are these ions and what do they do?A: There are six ions that are important for regulating pH and contributing flavor. These are:
- Calcium (Ca) - This is one of the most important ions. It helps lower mash pH and also assists in enzyme activity during the mash. It is generally a beneficial ion although too much can cause haze and it can also precipitate phosphate, which is necessary for the yeast.
- Carbonate (CO3) and Bicarbonate (HCO3) - These ions are usually lumped together because they really do the same thing. They buffer the mash pH and prevent calcium from lowering it. It also impedes enzyme activity and can contribute a harsh bitterness in hoppy beers. In general terms, the more carbonate your water has, the more calcium you need in order to counteract these effects.
- Magnesium (Mg) - This ion also lowers mash pH but isn't as effective as calcium. In concentrations greater than 30 ppm it can also contribute a sour-bitter flavor to the beer.
- Chloride (Cl) - Enhances the sweetness of beer in concentrations greater than 250 ppm.
- Sodium (Na) - Gives the beer a round smoothness in concentrations of 75-150 ppm. This is why you'll sometimes see someone adding table salt (NaCl) to a glass of beer.
- Sulfate (SO4) - Enhances hop "sharpness" in hoppy beers. This can be good or bad depending on the style of beer. In the presence of sodium, this sharpness becomes harsh and the only solution is to reduce hopping rates.
Q: What other factors should I be concerned about?
A: Those six are the main things but there are a few other things to watch for:
- Iron - Iron will obviously impart a metallic taste in high concentrations. But it can also cause haze and hinder yeast activity. Unless you get your water from a private well, iron is rarely a problem.
- Chlorine - Not to be confused with chloride, chlorine is used in many municipal water supplies to prevent the growth of bacteria. Most of the time this is not a problem as it will simply boil off. However, in high concentrations it can cause a phenolic "band aid" flavor in your beer. If this is the case, you should let your brewing water stand in an open container overnight to let the chlorine evaporate. You can also filter your water with active charcoal to remove more than 99% of the chlorine.
- Chloramine - Chlorine's evil twin. Used for the same reason as chlorine but it doesn't boil off or evaporate. It must be removed by treating the water with campden tablets.
There are a few other ions that can cause unwanted flavors but these are rarely a problem so we won't go into them here.
Q: How important is my water's pH?
A: Not very. You would think that the higher the water pH, the higher the mash pH would tend to be but that's not how it works. Mash pH is primarily governed by the relative concentrations of calcium and carbonates in the brewing water.
Q: How do I find out what's in my water supply?
A: One of our members, George Schmidt, has compiled a database of water profiles from across the country. Check in his database [Edit: Database is currently off-line.] to see if your zip code is listed. If it isn't you can usually obtain this information by calling your local utility company. Sometimes the utility will post this information on a website so try googling for that also. If they are uncooperative or if you use a private water supply, you can obtain a water analysis from Ward Laboratories for $15. Order test W-6, the household water test. Once you have your water analysis, please visit George's website and enter your information into his database.
Q: What should I do if my water is too high in carbonates?
A: There are a few things you can do, depending on how much trouble you want to go to and what you want to accomplish.First of all, it might not even be a problem if you primarily brew dark beers. Dark roasted malts are more acidic than pale malts and they will counteract the effects of the carbonates. This is why before water chemistry was understood, only dark beers were brewed in places like London and Dublin where the water was high in carbonates.But if you want to brew pale beers, you'll have to take some sort of action. The easist solution is to simply add more calcium to the mash. You can add calcium in one of two ways: calcium sulfate (a.k.a, gypsum) or calcium chloride. Because gypsum also introduces sulfate ions, this is best used in hoppy beers like pale ales, IPAs, barleywines, etc. In other types of pale beers such as pilsners and tripels, calcium chloride is better so that you avoid the sharp hop bite from the sulfate ions.
Another solution is to boil all of your mash water before hand for about 30 minutes. Heat causes the carbonate ions to bind with the calcium and precipitate as calcium carbonate (chalk). Once the water has cooled, you'll notice a dusting of white powder in the bottom of the pot. Simply rack the water off of this precipitate. However, note that you must have sufficient calcium in the first place or no reaction can take place. Provided there is enough calcium, boiling will remove all but about 30-40 ppm of bicarbonate. For every 5 ppm of bicarbonate removed, about 3 ppm of calcium will also be removed. If your water is high in carbonates but low in calcium, this is not a solution for you.
You can dilute your water with distilled or reverse osmosis water. Depending on how high your carbonates are, you can often get them into reasonable levels just by diluting.
Acidification is a fairly straightforward process of adding food grade acid to your brewing water. Many acids are suitable but the easist to use are probably phosphoric and lactic acids. Be careful when adding acids to your brewing water. While it's hard to completely wreck a batch by putting in too much gypsum, too much acid can cause a sharp, sour tang. Acidification of sparge water is a very good idea for fly spargers. This technique prevents leeching of tannins from the grain husks during the sparge. Add enough phosphoric or lactic acid to drop the sparge water down to about pH 5.7-5.8.For a discussion of how to use slaked lime to remove bicarbonates from your water, see the next post. [Edit: the next post is missing for some reason - MB]
Q: If I want to add salts or acids to the water, how much should I add?
A: This is almost impossible to answer due to the complex nature of water chemistry. Also your grist composition is going to affect the outcome as well. If you want to invest in a pH meter, you can simply add salts until you hit the correct mash pH (5.2-5.5). However, if you prefer to use trial and error, I'd start with about a teaspoon of either gypsum or calcium chloride and adjust from there if necessary. If you notice a very low efficiency, water chemisty might be the culprit so you can try increasing the dose to see if that helps.
Q: I've heard that some brewers try to match the water in certain cities when brewing beers associated with those cities. How would I go about that?
A: I'm not a huge believer in this technique. First of all, back in the bad old days, the brewers in those cities often rued their water. They adjusted their recipes to accomodate the water, not the other way around. On the other hand, adding salts to water to approximate the water of Burton-on-Trent or Dortmund can sometimes be a good idea. For many other styles it makes no sense whatsoever. For example, nobody in their right mind would add a bunch of carbonate to a saison so that their water was "authentic". Saison brewers hate their high-carbonate water and go to great lengths to acidify it.
But let's say that for whatever reason you're going to try to match your water to another water profile. The first condition that must be met is that the levels of these ions must be lower in your water than in the target water. If this is not the case, you must dilute your water with ion-free water. There are six salts that are commonly used. Below is a chart that tells you for a gram of each salt how much of each ion is contributed (in ppm) to a gallon of water. To pull this off, you're going to have to know your own water profile. You can't get to where you're going if you don't know where you are.
Gypsum (CaSO4) - 61.5ppm Ca + 147.4ppm SO4
Epsom salts (MgSO4) - 26.1ppm Mg + 103ppm SO4
Canning salt (NaCl) - 103.9ppm Na + 160.3ppm Cl
Baking soda (NaHCO3) - 72ppm Na + 189ppm HCO3
Calcium chloride (CaCl2) - 72ppm Ca + 127.4ppm Cl
Chalk (CaCO3) - 105.8ppm Ca + 158.4 CO3
NOTE: Don't use iodized table salt because iodine is toxic to yeast. Instead use kosher salt or canning salt, which are iodine-free.This can get pretty tricky trying to balance out the relative amounts of each salt addition. So I recommend using some software to help out. ProMash and BeerSmith both contain water profiling tools. Another good resource is BreWater 3.0, a freeware Windows utility for analyzing and synthesizing brewing water. Also take a look at Ken Schwartz's water primer.
Q: My city adds chlorine to my water. Is this bad and if so, how can I get rid of it?
A: If the chlorine dose is not very high, it's ok to just brew with it. However, it's always better to dechlorinate it, particularly if the water smells of chlorine fresh out of the tap. You can let the water sit out overnight and the chlorine will evaporate. You can also add a teaspoon of hydrogen peroxide to your brewing water and the chlorine will be removed in about a minute.
Q: I've found out that I have chloramine in my water. What can I do?
A: Chloramine is very difficult to remove from water. It doesn't evaporate out, you can't remove it by boiling and treating with an active charcoal filter only removes about half of the chloramines. The best treatement is to add a half of a campden tablet per 5 gallons of water. Simply crush the tablet, stir into the water (while cool) and let stand for 5 minutes.
Q: Are there any online calculators or spreadsheets that I can use?
A: Here's one: https://www.ezwatercalculator.com/There is also John Palmer's residual alkalinity spreadsheet: English Units and SI Units.
Q: I'm an extract brewer. Should I be concerned about my water?
A: 
Now you tell me! Extract brewers need to pay much less attention to their water than all grain brewers for the simple reason that they don't have to worry about mash pH. However, an extract brewer might want to add some gypsum to an IPA to enhance the hop bite. But it's good to know roughly what sort of water you have. You wouldn't want to add a lot of gypsum to water that already has a lot of sulfate in it.
[NOTE: I'd like to thank Dave Miller, author of The Complete Handbook of Homebrewing. This FAQ leans heavily on you, my man.]
