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Reading a Water Report

While there is a great deal of science involved in the entire brewing process, none of it seems to frighten new brewers as much as the science of water chemistry. Something about adjusting water ions using various salts just seems to be tough to grasp for a lot of people new to the hobby. While there is always something new to learn in water chemistry, it isn’t hard to become comfortable in knowing what ions are of importance to brewers and what the effects of various salts are and how to use them. Water chemistry can be tricky and it takes some time to get your head around it fully, which is why it is good to start with the basics. If you are looking to make adjustments to your water then it is very likely you will need to understand how to read your water report. A water report tells you what your water consists of and you can normally get it from your local council or water supplier. There are also companies who will analyse your water for a small fee which may be worth doing.

In some cases you may find a lot of unnecessary information in your water report which can be confusing and in other cases there may not be the information we as brewers are actually interested in, which can be equally confusing! To make things simple, the ions that are of interest to us are;

Calcium Ca+2
Magnesium Mg+2
Total Alkalinity CaCO3
Sodium Na+1
Chloride Cl-1
Sulfate SO4-2

These reports will normally be shown in ppm (parts per million) or in mg/l. The top three ions are highlighted because it is these three that influence pH at various stages of the brewing process. Sodium, Chloride and Sulfate do not affect pH but will affect flavour.

So what should the figures look like on your water report? Well, there are ranges that work well for brewing water and this is where adjustments come into play. Your water report will probably show that the ions in your drinking water don’t necessarily fit into the range that is ‘acceptable’ for brewing certain styles so you will need to be able to make adjustments in order to bring these figures closer in line.

So if we look at each ion in turn we can see what the recommended brewing range is and you should be able to see on your water report where about your figures fall;

Calcium: 50 – 150 ppm

–        Calcium is hugely important for brewing as it affects clarity, flavour and stability as well as acting as a yeast nutrient and it helps with enzyme and reactions. Calcium increases mash acidity and helps with the extraction of hop bitterness. Calcium is also the primary determinant of ‘hardness’ in water.

Magnesium: 10 – 30 ppm

–        Magnesium has many similar effects to Calcium in that it is an enzyme cofactor and yeast nutrient and accentuates beer flavour. It is not as effective when it comes to acidifying the mash and can contribute to astringent bitterness if added in excess.

Total Alkalinity

–        Alkalinity refers to the concentration of carbonate and bicarbonate in your water. Alkalinity raises the pH of your water which can make getting your mash pH difficult when brewing pale beers (you would need to acidify your mash). Water hardness on the other hand refers to the concentration of calcium and magnesium ions in your water. Hardness and alkalinity will typically be shown as CaCO3 on your water report.

–        Total alkalinity is probably the most important figure on your water report as high alkalinity raises the mash pH out of the target brewing range and this can cause issues with your mash.

Sodium: 0 – 150 ppm

–        Sodium contributes a sour, salty taste that can accentuate beer flavours at reasonable levels. Poisonous to yeast and harsh tasting when in excess. As a general rule, brewing with low levels of sodium will result in a cleaner flavour profile for your beers.

Chloride: 0 – 250 ppm

–        Chloride enhances beer flavour and palate fullness. It increases the perception of sweetness, or mellowness, increases beer stability and improves clarity. Above 300 ppm though chloride can have a negative impact on yeast health.

Sulfate: 0 – 350 ppm

–        Sulfate produces a dry, fuller flavour, some sharpness. Strongly bitter above 500 mg/L but this is characteristic of some British ales. Levels of less than 150ppm recommended.

These are the figures that are of the most importance to brewers and are the figures you should be looking for in your water report. Once you have these figures and understand what they mean it should be quite simple to use water calculators to adjust your water depending on the style of beer that you are making.

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