The Importance of Water Ions

A core ingredient of beer but one that is often overlooked, water can have a very important effect on your end results.

This week, Dave from our UK office talks us through the different ions that we as brewers are interested in and what effect they have;
“For brewers, when we talk about our brewing water there are essentially a few things which are important to us. Firstly is pH, and more specifically ‘mash pH’. Get the pH of your mash right (in the range of 5.2-5.5) and normally your pH will fall within acceptable levels for the rest of the brewing process.
So firstly we will look at the pH of our water and what effect the various malts we use in our grist have on the pH (specialty malts are acidic and so will lower the pH of your mash) and we make adjustments to bring the pH into the acceptable range.
After our pH is sorted we will then look more specifically at the ions in our brewing water. The ions will be present in different levels depending on your source water but each ion will ultimately play a role in the end taste of your beer, either directly or by altering the perception of maltiness or hop character.
The ions we are particularly interested in are; calcium, magnesium, bicarbonate (alkalinity), sodium, chlorides and sulfates. So what are the effects of these various ions?
Calcium is extremely important for brewing water. It offers very little in the way of flavour contribution but it is vital for increasing mash acidity (if you brew with very alkaline water), assisting with enzyme activity, extracting hop bitterness, reducing haze and decreasing wort colour. Usually present in levels between 5-200 mg/L. To add calcium you have the option of calcium carbonate (chalk), calcium sulfate (gypsum) or calcium chloride.

Calcium chloride
Calcium Chloride
Useful for promoting proper enzyme activity and also acts as a yeast nutrient, magnesium in small quantities can help to accentuate the flavour of the finished beer. However, at excessive levels it can impart astringent bitterness. Levels should be between 10-30 mg/L.

Magnesium sulphate
Magnesium Sulphate
Sulfates are particularly important in hoppy beers – making both hop character and aroma more prominent and increasing the perception of bitterness. Excessive levels lead to an undesirable bitterness, above 500 mg/L (though this level can be acceptable in some British ales). Normal levels are 0-350 mg/L and gypsum is the most common salt used to add sulfates (though Magnesium Sulfate is an option).

Gypsum (Calcium sulphate)
Gypsum (Calcium Sulphate)


Chlorides enhance the beer flavour and perception of palate fullness, an important aspect of mouthfeel. This ion will also increase ‘sweetness’ or ‘mellowness’ making it highly desirable in malt forward beers. Long term this ion increases beer stability and improves clarity. Above 500 ppm and you will experience a negative effect on fermentation. Usual levels are between 0-250 mg/L.
Sodium can be used to add alkalinity to your brewing water as well as improving the flavour and mouthfeel of your finished beer.  At excessive levels it is harsh tasting, salty and poisonous to yeast. Usual levels are between 2-100 mg/L.
So those are the key ions, their effects and the typical levels they can be found at in brewing water. Remember;
  • To increase acidity you need to add calcium
  • To increase alkalinity you need to add sodium
  • Carbonates have a positive effect on dark malts, mellowing harshness
  • Sulfates have a positive effect on hoppy beers – increasing hop aroma and flavour
  • Your sulfate to chloride ratio affects the balance of hoppy or malty in your beer. More towards the sulfate side and hops will be dominant whereas a greater chloride ratio is useful for sweeter, maltier beers.”

How many of you make changes to your brewing water? Do you find that it has improved the quality of your beers overall?

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