Wednesday, March 30, 2011
Adjusting brewing water
I have finally reached a point where ignoring the brewing water quality/properties is no longer possible, so here we go, starting a whole new chapter in brewing beer, water chemistry.
I recomend for anyone planning to go this path is first get a water analysis done for your brewing water. That is a requirement before you start doing anything. You must first know what is in your water before you attempt to change anything. A complete water analysis only cost around $20 at wardlabs.com and has everything you need to know. I have investigated other labs but you cant beat this price.
Second, you will need to get a water PH tester. Prices will vary from $50 to many hundreds of dollars, but I recomment something around $100. You can get very good PH meters in that range, at least good enough for brewing beer.
This post is not intended to teach anyone water chemistry since I'm just starting and not an expert in any aspect, but feel free to use this as a start point.
Once you get your water report, you can then identify what types of beer would better suit you water profile or what changes you would need to make to your water to fit the styles you want to brew. Basically, the more minerals in the water or the more "hardness" (to a certain degree), the best for darker beers. The less hardness, the better for lighter beers.
There will be cases where your water has so much stuff in it ( calcium, sulfates, chloride and others) that you just can't use it for brewing. For those with this water profile, the only way is to either mix it with reverse ormosis water (RO) or distilled water(DI) in order to lower the concentration of these minerals. In some extreme cases, a brewer would have to use DI water only, trying to add some vital minerals from ground up.
The basics of brewing water chemistry is to make adjustments to your brewing water in order to:
1)Allow your mash PH to be between 5.2 to 5.4, which is the mostly recommended range. This will increase your mash efficiency and overall beer quality.
2)Provide vital minerals that help your yeast health, improve yeast fluculation and therefore get more clear beer, and stablish a beer profile that you like, malty, bitter, etc.
The first on this list is considered the most important goal, the mash PH. Mash PH, from what I learned so far, is driven my two basic variables:
-Grain bill, specially the crystals and dark roasted grains. These malts are known to drive the mash PH down.
With your water report and your grain bill, you can use few free tools on the web to estimate what your mash PH will be, as well as the amount of each minerals, like calcium, magnesium, chloride, sulfates, etc on your mash water. I have checked few of these tools and have posted the links to each of then at the "technical stuff" page, on the top menu. Try all and choose one that you like best. All pretty much do the same thing for you, you plug in your water composition, the type of beer you plan to brew, and it lets you make additions showing the estimated mash PH and final mash water profile.
These are some basic guidelines on what your mash water should contain:
=>Calcium(Ca) - From 50 to 150 ppm - good for yeast health and beer clarity. Also increase mash efficiency.
=>Magnesium (Mg) - From 10 to 30 ppm - important yeast nutrient. This may come from the barley, so adding Mg may not be necessary, but it would not hurt to do so.
=>Sulfate(SO4) - From 50 to 350 ppm - acentuates bitterness
=>Sodium (Na) - From 0 to 150 ppm - at low concentration it can accenuates the sweetness of the beer.
=>Chloride(Cl) - From 0 to 250 ppm - acentuates the sweetness and maltyness. The Cl to SO4 ratio is claimed to define the beer profile, from bitter to malty, but some argue that the actual amounts of Cl and SO4 are as important and that Cl should stay below 100ppm and SO4 to a minimum.
All these elements will define, together (specially Ca), how much you water is succeptable to PH changes, or in order words, how easy would the PH change. This PH change will come from the grain bill, specifically from the crystal and roasted malts once added to the mash water.
A basic rule for water hardness would be, as CaCO3 ppm:
Soft: 0-60 => good for any styles of beer. May not require any salt additions, depending on the style you are brewing.
Moderate: 61-120 => Best for ambers up to brown ales
Hard: 121-180 => Best for dark styles like stouts and porters. Mixing with RO or DI water may be necessary
Very Hard: >181 => Mixing with DI water is required to lower mineral concentrations. The rate of mix will depend on how high the concentrations are and the target beer style, but using 100% RO or DI water is commom practice
The most commom salts/minerals used to adjust brewing water are listed below:
-lowers mash PH, add calcium and SO4, lower Cl/SO4 ratio
-lowers mash PH, add calcium and chloride, raises Cl/SO4 ratio
-lowers mash PH, add magnesium and SO4, lower Cl/SO4 ratio
-raises mash PH, add sodium, no affect in Cl/SO4 ratio
Non Iodized Salt(NaCl)
-no affect on mash PH, add sodium and Chloride, raises Cl/SO4 ratio
-raises mash PH, add calcium, no affect on Cl/SO4 ratio
I have soft water and here are two examples of what my approach would be to adjust my water when brewing these styles of beer:
My water profile:
As you can see, my water has almost nothing in it, close do DI water, so I can expect I will need to add some minerals in any styles of beer.
Brewing a light pale ale:
Total grain bill(lb)=12
Crystal malt used(lb)=2
Roasted malt used (lb)=0
Expected SRM=8Mash water volume(gal)=4.5
Intended beer profile = malty
Plugging all informatin above into one of the tools I listed, this would be my mash water profile:
From that we can see that the mash PH is too high, so the first step is to add something to lower the PH to between 5.2 and 5.4.
One route to lower PH is by just adding acid, like lactic or phosphoric acid. That route is fine IF you already have minimum amounts of some important minerals, like Ca, Cl and Mg.
Because the water lacks of almost anything, the Ca, Cl and Mg are much lower than recommended minimums, so what I would dois to add these minerals and lower PH at the same time.
-4g of calcium chloride(CaCl2)
-3g of Epson Salt(MgSO4)
I lower my mash PH to 5.4 and at the same time I raise these minerals to:
-Ca from 8 to 72
-Mg from 1 to 17
-Cl from 4 to 117
-SO4 from o to 69
These are values that falls between the recommended range and I also get a Cl/SO4 ratio towards a malty profile.
Now, adding a small amount of lactic acid, about 0.5g, I would lower the PH further to 5.37.
The listed salt additions would be added to the mash water before adding the grains. 15min into mashing, a sample is taken for a PH test to confirm it is within 5.2 and 5.4. At this point, if the PH is too high, some acid can be added and stired to lower the PH. If the PH is too high, some baking soda or chalk could be added to raise PH to the target value.
From my experience so far, you can get pretty close to your target PH and no late salt additions are necessary.
Brewing a Stout:
Total grain bill(lb)=14
Crystal malt used(lb)=1
Roasted malt used (lb)=0.75
Mash water volume(gal)=5
Intended beer profile = malty
Plugging this info into the tool, I get the following mash predictions:
As seen, the PH is too low. That is because the water is soft and PH is easily lowered by the acidity from the crystal and roasted malts. All minerals concentration as also low, just like the previous example.
So basically, we need to add something to raise the mash PH. From the list of commom salts used, we could add either baking soda or chalk to rise mash PH.
Adding 8g of baking soda would raise our mash PH to 5.26, which is on target.
I would also try to add some calcium and chloride, no a lot so I don't lower my mash PH, but just enough to reach the recommended minimums.
Adding 3g of Calcium chloride would provide 51 ppm of calcium and 80 ppm of chloride and PH would be 5.22, still on target.
As last option and to garantee that you have magnesium enough for you yeast to be happy, 2g of Epson Salt could be also added to raise Mg from 1 to 11 ppm. That would still keep the mash PH on target and final Cl/SO4 ratio would be close to 2, suggesting a malty beer profile as planned.
At last, here are the tools I'm using for my water testing, have worked great so far, so take these as suggestions in case you are planning to start adjusting you water. The first is the precision scale to weight the salts to be added and second the PH meter.