A Water report is the first step in understanding your brewing water. If you pay a monthly water bill, then you already have access to your report. I used to get it in the mail once per year. You should be able to call your water company and request one or go online and get it. Personally, I like to know my specific water - especially if I am running it through another filter. The best way to do this is to send a sample to Ward Labs (1-800-887-7645). Their W-6 "Household Mineral Test" is $21 and will tell you what you need to know. I have sent several samples to them and they usually have the results 2 days after they receive it. Simply take a 12oz or larger water bottle, rinse it out several times with the sample water, and sent it to their P.O. Box with a note. Include your name, address, what test you want (W-6) and your email address. They will send you the results in a .PDF file and you can pay with your credit card on their web site. Keep in mind that your water will not be the same throughout the year. You may want to send in a sample every 3-6 months to get a real idea of your water's minerals, pH, and carbonates. More about this in Salts section.
The single most important part of the water report is the buffering capacity of the water (aka: alkalinity/bicarbonate). The pH does not matter if the water has a low buffering capacity. The amount alkalinity/bicarbonates is what gives that water a low or high buffering capacity.
This should not be confused with hard water. Hard water is the amount of calcium and magnesium and other trace minerals in the water. Since, calcium and magnesium are desirable, it is good to have hard water.
A buffer is defined as a solution that resists changes in pH when acid or alkali is added to it. Since malt is naturally acidic it will cause the water to drop in pH. The desired mash pH is 5.2-5.4 at room temp or 4.9-5.1 at mash temp. When you get your water report, note the bicarbonate and total alkalinity. Either of these can be used to figure the buffering capacity of your water.
Water makes up more than 90% of beer's total mass. At the same time, many homebrewers don't consider water an ingredient. Who knows, maybe your water will make great beer for you and the styles you like. However, for those of us who want to fine tune our brews, it is very useful to know how to adjust our water to fit the beer styles we make.
Avoid Chlorine in brewer’s water. It can ruin the flavor and aroma of your beer. Since municipalities use chlorine to provide the public with healthy clean water, it will need to be removed. This can be accomplished by adding campden tables, boiling the water, or running the water through a carbon filter.
Campden tables are easy to use and effective. Add 1 tablet to 5 gallons if you have very little chlorine in you water, or up to 1 tablet per gallon if you have a lot of chlorine. Add the tablets to your brewing water before mashing or adding anything to the water. I would give it a little time to work. Click here for an in depth discussion of the matter. Personally, I do not like adding anything extra to my beer. On the other hand, campden tables break down chlorine into products that yeast use for nutrients.
Boiling the water can evaporate the chlorine over time. The amount of time to boil is often quoted as 15 minutes. However, if some studies have shown that it can take up to 2 hours to boil off the cloramine (a chemical sometimes used by some municipalities to treat the water).
The best choice by far is to run your brewing water through a carbon filter. This is my choice. I have well water with a high iron count. Therefore, I have a chlorine injector, carbon filter, and water softener. I do not want the softened water in my brew because the softening process exchanges the ions I want with sodium which I do not want. I simply bypass the softener and voila, clean non-chlorinated water.
An under-the-sink carbon filter works as well. However, for those who love to build and create their own equipment, here is a DIY project.
If your water is clear and tastes good, chances are you can make good beer with it. If you are already making good beer and want to move to then next level, then continue to the Salts and Acids section.
Let me explain a few things first. When it comes to the mash, there are two kinds of malts: those that must be mashed to convert its starches to sugars and those that can be steeped because their starches have already been converted to sugar in the malting process. Also, pale malts have a higher pH than darker malts when mashed. The most acidic malts are the crystal variety followed by black roasted malts.
Many brewers know that the pH of the mash should fall between 5.2-5.6 (5.2-5.4 is more desirable) at room temperature. The malt will naturally "buffer" the mash to get it close to that range. Let’s suppose that your water is high in these buffers. If you mash only pale grains then the mash pH might be too high (above 5.6). In this case, the addition of some dark and crystal grains can help lower the pH because they are more acidic. Dark beers/mashes favor water with a high buffering capacity and high pH and help to bring the pH into range.
On the other hand, if your water is soft and has a low buffing capacity, then the use of too many dark grains can bring the mash lower than the desired range (below 5.2). Light colored beers/mashes favor water with a lower buffering capacity regardless of pH.
So does this mean that you can only make light or dark beers based on your specific water? No, it just means that some additions are needed. Remember, that if your water is clear and tastes good, chances are you can make good beer with it. If you want to make better beer and have more control over the flavor profiles then continue reading.
There are numerous factors that come from having the correct mash pH. In fact, the pH of the mash sets the stage for the rest of the brewing process all the way to the poured glass. Without getting into too much detail, take my word for it - it is important for great beer.
There are three salts that raise the pH of the mash and three salts that lower the pH of the mash. I mash with grains that “must be mashed” and add the dark and crystal malts (that can be steeped) during the last ten minutes. This means that mostly pale malts are use in my mash during the saccarification rest (the temperature at which starches are converted to sugars by enzymes). In his book “Making Better Beer,” Gordon Strong recommends a process that I incorporate in my brew sessions. He suggests that adding the dark and crystal grains at the end of the mash will subdue the harsher flavors that come from these grains. Just like cold brewed coffee, it has the flavor of coffee without the bitterness. The shorter the time that dark grains are in hot water, the less bitterness is extracted. There is a minimum time to mash like this. About ten minutes is needed for the most of the sugars to go into solution. Using this method, I have to lower the pH of the mash by adding one of the following salts: Calcium Chloride adds calcium and chloride; Calcium Sulfate (Gypsum) adds calcium and sulfate; Finally, Magnesium Sulfate adds (you guessed it) Magnesium and Sulfate and lowers the pH slightly. These three salts do not lower the pH of water. Instead, when they are added to the mash they react with the phosphates and make the mash more acidic.
If you have to raise the pH of your mash due to a very low buffering capacity of your water and/or the abundant use of dark and crystal malts in the full mash, then there are three salts that can be added: Sodium Bicarbonate (baking soda - pH 8.4) raises the pH by adding alkalinity; Calcium Carbonate (chalk - pH 9.4) adds calcium and raises the pH; The third salt is Sodium Carbonate. This maintains a pH of about 11.4 and is extremely effective for raising pH and. It should not be necessary to use this but if you do, it can be made from sodium bicarbonate.[procedure coming soon] These three pH raising salts do not mix with water very well. They work better by being added directly to the mash.
Keep in mind that the above six salts do influence the mash pH, but only a little. The majority of the buffers are in the phosphates of the malt itself. Even acid additions only change the mash pH slightly.
Next are the salts that help bring out certain flavors in beer. They are Chloride (not Chlorine) and Sulfate. A malty beer will favor more chlorides. A more hoppy beer will favor Sulfides. The general ratio is 2:1 or 1:2. In other words, a beer with a 2 chloride to 1 sulfite ratio will enhance the malt and give a rounder, fuller flavor. A ratio of 1 chloride to 2 or more sulfites will accentuate the hops and provide a more crisp profile. [Note: A malty black beer can benefit from a 3:1 chloride to sulfate ratio and some brewers have been known to go as high as 1:9 chloride to sulfate ratio - but not me.]
As for the rest of the ions, the goal is to keep them in check. Calcium is important for the yeast in fermentation. Generally, 50-150ppm is acceptable. Magnesium is needed, but in very small amounts 10-30ppm. Sodium is not necessary for fermentation, but a little (<150ppm) can enhance the flavor of beer, just like is does to food.
CONCLUSION (TO WATER AND SALTS)
All this may be a little overwhelming, so I bring it all home. Normally, any six of these salts would be added to the mash because they require heat and a lower pH to go into solution. There have been questions raised about how much the salts go into solution during a one hour mash rest. I have come up with a solution. (Note, this works for the 3 salts that lower mash pH. I have never had to raise the pH in my mash do to using the “Strong” method). I prepare the water, add the salts, add phosphoric acid to a pH of 5.5 ish, and letting it rest for 3 or more days. The salts all integrate into the brewing liquor. Giving it a shake once or twice wouldn’t hurt.
At normal pH levels, adding phosphoric acid can precipitate calcium from the brewing water. When lowering the pH to 5.5 this is not a concern. [Note: Some brewers use lactic acid to lower pH, but lactic acid can also add sourness to beer if over used.]
A great instrument to reduce all this complexity is the EZ Water Calculator. This is a simple but powerful tool to figure the additions needed for your brew water. I use this every time I brew. Simply plug all the numbers in, including acid addition, and you’re on your way. [Note: I have figured that 10% phosphoric acid is the same as 14% lactic acid]. Notice that this calculator has a target of 5.4-5.6 pH. While this is acceptable, many professional brewers these days shoot for 5.2-5.4. Just don't overdo it. If you are adding salts by the spoonful and more than 2tsp/gal of 10% acid, then you might be going too far. Take it slow and experiment. It took me several brews to get it right - and then my water changed. Such is a brew day.
This is what I do. My water is high in alkalinity, so I add 1 gallon of distilled water to each of 2) 5 gallon jugs. This cuts the alkalinity by 20%. Then I fill the jugs with my chlorine free water, add brewing salts depending on the style of beer I am brewing (2:1 or 1:2 ratio) and add phosphoric acid to attain a pH of about 5.5 (a pH meter helps). Then I let it sit for 2-3days to allow the salts to integrate into the water. I tried pulverizing and boiling the salts, but they did not go into solution any better than just letting it sit. This lower pH helps the salts to go into solution. At the pH of typical house water, some of the salts will not readily go into solution.
The other advantage of have all the brewing water at a pH of 5.5 is that during fly sparging, you will not draw out the astringency of the malt husks as the buffering capacity of the mash reduces.