Since your brewing water constitutes the majority of your homebrew, it makes a difference in the final taste of your beer. The minerals present can affect the starch conversion of your grains.
For extract brewers, you don't have to worry about this. The extract will have all the minerals needed from the water at the location that the extract was made. If you are having problems with some off flavors, or can't seem to make certain types of beer by adding your own water to extracts, try using distilled water. If you are adding mineral salts to your water when using extracts, you may be over doing it since these minerals are already in the extract. Call the manufacturer to find out the water profile of the brewery that made the extract. You can then make adjustments from there.
If your brewing water smells like a swimming pool, you can boil it to get rid of the chlorine. Your water may be treated with chloramines instead of chlorine, and boiling won't affect it. You can add a campden tablet (potassium metabisulfite-available at winemaking suppliers) to your brewing water to treat out the chlorine or chloramines. You do get a slight increase in sulfate and chloride ions after using this method though (<10 ppm) and one tablet should treat up to 20 gallons of brewing water. The reaction takes place within a few minutes at room temperature. Another good way to treat your water is by carbon filtering. Using activated carbon should remove most or all of the off flavors including chlorine in your water, but won't affect the minerals.
You can use a water softener only if you are brewing with extracts. Too much of the necessary calcium and magnesium is removed through ion exchange, usually with sodium, for it to be used with all grain brewing. The mash needs these chemicals to convert the starches efficiently, increase the efficiency of the enzymes, and for fermentation later on.
Lastly, you can use bottled water to brew with your extracts. Only use bottled-distilled water to dilute your hard tap water, (RO (reverse osmosis) water will work the same way).
For a more detailed look at treating brewing water for extract brewing, check out John Palmer's How To Brew. His sections on water are some of the most thorough of any of the homebrewing books.
If you are an all grain brewer, brewing water chemistry becomes more important. I recommend you get a brewing water analysis done at Ward Laboratories, inc. It's inexpensive (around $16 or so) and will let you know exactly what's in you brewing water. If you want to learn all about the chemistry of brewing water (also called liquor), it's a complex subject. For the rest of us, here are some brewing water basics.
Water falls from the sky in its purest form, then trickles through rocks and sediment to your aquifer. If those rocks are limestone, which the majority are, your water will absorb calcium and carbonate . If the rocks are dolomite, the water will absorb magnesium and carbonates. Volcanic rock doesn't affect it much, but occasionally you'll find areas of gypsum and the water can absorb calcium and sulfates. All these minerals now in your water make up its hardness. The word hardness was originally used to describe how well a water lathered with soap.
A water's hardness can be of two types. One is called temporary hardness, or carbonate hardness. Temporary hardness is usually evidenced by higher alkalinity which increases pH. Many beers were developed around water high in carbonates. In those days, they didn't understand about water chemistry, but they did understand that when they tried to brew a light, highly hopped beer, they got very harsh, astringent flavors which were not pleasant. By trial and error, these areas found that dark beers tasted great. We now know that the darker malts have enough acidity to lower the pH into the proper brewing range (5.1-5.5) where the tannins aren't extracted. As a result, the dark beers were smooth and balanced with no harsh bitterness. So remember this: If you have high alkalinity in your brewing water, brew more dark beers.
There are ways to get rid of most of the hardness from carbonates. Boiling your water is the best method. Everyone has noticed the flakes floating at the bottom of a pot after boiling the water. These are the carbonates being precipitated out as calcium carbonate. Carbonates depend on dissolved carbon dioxide CO2 (which in water forms carbonic acid CO) to stay soluble. So, remove the CO or carbonic acid and the carbonates will fall out into the white flakes.
Boiling to remove hardness works best with a source of calcium which gives the carbonates something to combine with and allows them to fall out of solution. Calcium can be added to your brewing water in the form of calcium hydroxide (slaked or hydrated lime) or calcium chloride (a common salt). If you have moderately carbonate (alkaline) water, which is found in much of the country (not in wells, which can be much higher), Randy Mosher in Radical Brewing says that you can add about 1 teaspoon (3.5 grams) of calcium chloride or 2 teaspoons (8 grams) of gypsum per 5 gallons of water to help precipitate carbonates. He also reminds us that boiling will not remove all of the carbonates, but should lower it enough that you can make a pale bitter beer.
Other minerals are not welcome in your brewing water. Salts can give an impression of "savory roundness" to your beer as Randy Mosher says. But too much salt will make your beer taste, well, salty. Iron and manganese are both detrimental to the flavor, clarity and yeast health of your beer. The worst of the additions to your water is free chlorine or chloramine. Remove chlorine by boiling or carbon filtering and remove both chlorine and chloramine with a campden tablet.
Finally, two minerals which are beneficial are zinc and copper, as long as they are present in trace amounts. The yeast use these minerals as nutrients. Too much of these minerals can cause problems with off flavors and yeast fermentation.
Water high in sulfate, which causes permanent hardness, gives beer a dry fuller flavor (although it can be too sharp). Above 500 ppm sulfates in water can be strongly bitter. That's why it is kept around 150 ppm by dilution with distilled water, unless the beer will be highly hopped, in which case levels can be up to 350 ppm which will give your beer a cleaner bitterness.
If you are interested in the brewing water chemistry, I suggest you read New Brewing Lager Beers by Gregoray J. Noonan. The entire book is directed to those that like the technical aspects of brewing. It's a very good book and one you should have in your brewing library
For those that want to adjust their water for deficiencies, check out John Palmer's How To Brew section Using salts for water adjustment. It is a very good source of information and is indispensable for those that want to adjust their brewing water. Some brewing software have water adjustment tools. Utilize these tools if your water needs adjustment, or if you just want to experiment.
A quick overview of water types:
From Gregory Noonan's book New Brewing Lager Beers he gives the following uses for these common salts:
As an example, here is the analysis done by Ward Laboratories, Inc. of my tap water in South Central Louisiana:
Looking at the report, here is the analysis of my water: The pH of the water is not too important yet. The water must combine with the grain bill in your recipe before the pH should be taken. If the pH is then out of range, it can be adjusted.
The calcium level is below the recommended brewing range of 50-150 ppm as is the magnesium level which should be 10-30 ppm (magnesium is an important yeast nutrient), but as mentioned above, the yeast will get plenty of magnesium from the wort which derived its magnesium from the grains.
The biggest problem is the bicarbonate level of 303 ppm. The proper levels of bicarbonate are 0-50 ppm for pale, base malt-only beers, 50-150 ppm for amber toasted malt beers and 150-250 ppm for dark, roasted malt beers. My water is above even the highest recommended level of 250 ppm. The carbonates can be lowered to the 50-150 ppm level by two methods, boiling or dilution. The problem with boiling is that it can only remove the temporary hardness (which is the lesser of the total alkalinity as CaCO3-249 ppm or the total hardness as CaCO3-80 ppm). In my case the lesser is the total hardness as CaCO3 at 80 ppm. If the total hardness would have exceeded my total alkalinity, then most of the alkalinity could be removed down to the 50 ppm range (which has to do with the solubility constant of Calcium). In my water, only part of the alkalinity and almost all of the calcium (which is low already) will be precipitated when boiled (this is definitely not a good situation). I would need to add back more calcium to equalize the alkalinity.
If I wanted to lower my carbonate levels, there are a couple of methods I could use. One way of lowering carbonates is by adding slaked lime for a calcium source to precipitate the carbonates as calcium carbonate, and the other method is dilution. Adding slaked lime is complicated and must be done with care and precision. Dilution is much simpler and just as effective. I vote on dilution. But, if you want to try using slaked lime, the procedure from John Palmer's book How To Brew is listed here.
Click here to learn about using slaked lime or dilution for carbonate reduction.
Brewing water adjustments can be complex. But, if you are having problems with your beers brewed with only pale malts, or just want to take your brewing to the next level, it is a worthwhile endeavor to learn. In the Brew Strong segment on brewing water, John Palmer says that he thinks your beer's competition scores could go from the 30's up into the 40's by correctly adjusting your brewing water (if your water needs adjusting, and all of your brewing processes and sanitation are correct). The main caveats to remember are: know what your water's chemistry is and know why you want to make adjustments to your water.
The most important aspect of your brewing water's chemistry is its residual alkalinity (RA). If you only adjust one thing, work on that first. Getting the correct RA for your brewing water will insure that you get the proper pH in the mash.
To learn more about your mash's pH and how to adjust it, click here. A very good source of information is John Palmers book, How to Brew. John has worked up a spreadsheet that I often use to make adjustments to my water. Click here to download John Palmer's Residual Alkalinity spreadsheet at the bottom of the page. Once you have the spreadsheet downloaded, enter the numbers from your local water report. Then, each time you brew, go to the spreadsheet and work through the calculations to get the RA required to brew the beer. John makes it easy and all you do is follow the steps, 1-2-3. You have several choices for making chemistry adjustments here. One is dilution. If your water is way out of specs, dilute with distilled, deionized, or RO water. Enter the amount of water in the mash and what percentage you want to dilute it. Another method is by adding acid to the mash. John gives you two sources, hydrochloric acid and lactic acid. These additions will be small, usually around 1-6 ml. And the final method of changing your water chemistry is by adding salts, such as gypsum, calcium chloride, epsom salts, and baking soda. You can experiment with these until you get the final water like you want it.
If you get your water's residual alkalinity in the right range, the next thing to look at is your water's chlorides to sulfates ratio. John has set-up the spreadsheet to give you this ratio. He tells you whether your beer will end up being Very Malty, Malty, Balanced, Bitter, or Very Bitter, depending on the ratio of your water's chlorides to sulfate ions. These can be adjusted using the salts mentioned above. So, once you get the RA in line, and the chloride/sulfate ratio how you want it, you are all set. There is one more (optional) step available from the spreadsheet. You can adjust your sparge water by adding acids. Just input the amount of sparge water you are going to use, and the spreadsheet gives you the recommended amount of acid to add to your sparge water to insure you don't allow your wort pH to climb too high and strip out too many tannins (or polyphenols) from the grains in the mash.
As I get a little more familiar with John's spreadsheet, I'll try to work up a tutorial on how to best use it, but until then, you'll have to do as I do, work through it by trial and error. But just remember, just about every water has a beer that can be brewed from it without any adjustments. If your water is high in alkalinity, brew dark beers (or adjust it to brew light beers), and if your water is soft and low in alkalinity, brew light hoppy beers (or adjust it to brew dark beers). In my case, all I really have to do is filter out the chlorine with a carbon filter and my water is perfect for brewing all kinds of dark beers without any kind of adjustment at all.Back to All Grain Brewing