Getting to know your ingredients - Water (part two)

You can make good beers without knowing anything about brewing water.If you are lucky, you might choose an ideal grist for your water profile and things click into place by accident, resulting in the best beer you've ever drank. In general, if it's good enough to drink, it's good enough to make beer from. If you have high chlorine/chloramine levels in your water, you may want to just add half a crushed campden tablet to your brewing liquor to dispel them. Many brewers do this just in case. I'm not aware of any damage it can do if not entirely necessary, and they cost next to nothing. If you're happy to change a little more, please read on;

Water typically composes around 95% of our beer, so it’s very helpful when we start off with the right profile. It is often seen as an advanced topic, and it certainly can be, as can almost every other aspect of brewing when you go into enough detail, but it doesn’t need to be too complicated. 

There is plenty of software and many online applications to help us, so if we’re happy learning ‘how’ and willing to put the ‘why’ on the back seat for a while, you should be able to improve your beers quite easily.

It’s worth noting that brewing is a natural process, not a linear one, so the calculations made on our behalf by the software can’t be 100% accurate, but they should give us a very good indication of what can be changed to adapt our water profile to certain beer types.

I will be using my own water as an example for this post, looking at alkalinity, pH and the ratio between sulphate and chloride.

In order to examine this, I gathered some information from my local water supplier’s website and used a Salifert kH/Alk pack to test my waters alkalinity. This is what I found;

I was unable to obtain the Magnesium and pH, so have estimated them. Fortunately, they aren’t crucial to this exercise. 

The calculator on brewersfriend.com found here is an excellent resource for evaluating and adjusting our water chemistry.

I will concentrate particularly on the water used in the mash. It is important to get the pH here to a suitable range, most often quoted between 5.2 and 5.5 at room temperature. Getting it wrong may result in undesirable tannin extraction, lower efficiency, haze or just a generally lousy beer.
You may notice above, my estimated water pH is 8. This will naturally reduce when adding malt due to its acidity; darker grains imparting more acidity than lighter base malts.

Alkalinity & pH

It took me a while to ‘get’ Alkalinity, and if like me you find practical examples helpful, this video compares alkalinity to pH and assisted my understanding. Alkalinity is basically the buffering capacity in our water. It is the ‘bouncer’ on the door of the ideal pH club. The bigger the bouncer (the higher the alkalinity) the less our malt is able to naturally reduce the pH. For example, with my alkalinity of 28ppm CaCO3, when using 5kg of a 3 Lovibond base malt, my mash pH is estimated at 5.67. If Alkalinity is increased to 150ppm; the malt only brings it down to 5.84.

We can reduce our alkalinity by adding Gypsum (calcium sulphate) or Calcium Chloride (as well as other salts, but let’s keep it straight forward). In this example, it would take a fair amount of salt additions to reduce the alkalinity enough to get down to the ideal pH, which is not ideal. Another option is increasing the acidity. This can be achieved by adding darker malts or acids. Let’s suppose we want to make a pale beer, and are happy to increase the colour to 6 SRM. The calculator shows the acidity of the extra dark malts brings the mash pH down to 5.63 from 5.84. We can then add 150g of acidulated malt to nudge the pH down to 5.41 which is within the ideal range.

Calcium & Sulphate/Chloride Ratio

Returning to my own water profile, I notice my Calcium and Sulphate levels are low. I am reliably informed that the low level of Calcium could be a contributor to hazy beers which I have suffered with. I want to increase the levels of this from 36 to above 50, or preferably around 100ppm. I have a few options here – I could use Gypsum, Calcium Chloride, Chalk, Baking soda etc… etc…
As my Sulphate is also low, I will opt for Gypsum (Calcium Sulphate). A teaspoon (4g) of Gypsum bring my levels up to “normal”.

Another thing to consider is the balance between Sulphates and Chloride. If I wanted a hoppy beer, I would want a ratio favouring Sulphates and the opposite if a more malty beer is desired. After the addition of Gypsum, I now have 21 mg/l if Chloride and 95 mg/l of Sulphate, so the ratio between them is 4.5-1 in favour of sulphate. This is classed as “extra bitter”. 

Let’s suppose I’m making a beer that is only moderately hoppy. I could either add table salt to increase the chloride, or reduce the gypsum addition to half a teaspoon and make up the calcium deficit with half a teaspoon of calcium chloride. I would opt for the latter to keep additions to a minimum. This would bring the Sulphate to 70 mg/l and the Chloride to 42 – the balance now considered appropriate for slightly bitter beers.

To illustrate further, I will show my process of designing a water profile for a stout. The colour is 40 SRM and the grist contains 10% roasted colour, the total weight is 5kg. I will be using 35L of water in total, 12.5 of which in the mash.

After this information is added, because my water is naturally very low in alkalinity, the acidic malt has pushed the pH down to 4.94, so here we actually need to increase the pH. We will do this by increasing the Alkalinity, but I also want to increase the calcium and sulphate whilst attempting to balance the sulphate/chloride ratio towards chloride to help the malt character shine through.

If I add 3g of chalk (calcium carbonate) and 3g of bicarbonate of soda to the mash, this increases my calcium to 50 mg/l, the alkalinity to 105 and crucially, the mash pH to 5.2. I will address the other issues in the boil.

I would like to increase sulphates whilst balancing the ratio with chloride to favour a malty beer. To do this I can add 8g of salt and 4g of gypsum to the boil. The resulting water report looks like this;

The additions I have made give me what I wanted. A pH of 5.2, a suitable amount of calcium and a balance of sulphates & chloride favouring a malty beer.

This way of tackling water using a water calculator is very much trial and error, experimenting with additions and checking levels along the way, always mindful that each salt or acid addition will generally make more than just the desired change to your profile. If you can kill two birds with one stone, you should. Once you’ve played around with the calculator, you become more accustomed to its functions and it starts to look much more straight forward.

I can’t stress enough though, the theory isn’t going to be 100% accurate, but the alternatives are to either ignore the water and hope for the best, or spend huge amounts of time and resources testing and evaluating practical experiments.

I hope you have found this helpful, if you are interested in reading further, I highly recommend John Palmer's How to Brew. This is a comprehensive book detailing all aspects of brewing from beginner to advanced. I have a copy on hand on brew day and have found it helpful on many occasions. 

If you have made it this far, thank you for your efforts.The topic can be daunting and many brewers never get this far. I realise water isn't the most fascinating part to brewing, but it can make the world of difference. To quote John Palmer himself, "with a little knowledge about water, you can turn a good beer into a great one".

Please take the time to read my posts about hops, malt and water part one.