Friday 1 October 2021

Brewing Water Chemistry for Beginners


Water is the biggest contributing ingredient in beer - so it's perhaps ironic that it's often the last thing that home brewers look at adjusting or changing in their home brewing journey. This is something I'm certainly guilty of myself - so I'm writing this blogpost to hopefully break down some of the daunting and overwhelming concepts, to make them easier to understand and more importantly, implement into your brewing.

Adjusting water chemistry makes an incredible difference to your beer. It really does take it to the next level and turns a good beer, or a really good beer, into a great beer. For me, it was the missing piece of the puzzle as to why my beers never quite tasted, or even had the same mouth feel as commercially available craft beer.

I'm not a science guy myself - I wasn't particularly good at it in high school - and I think this is why most home brewers shy away from getting involved in water chemistry. It's difficult to understand, and most people probably think "how can I implement something into my brewing that I don't understand?" Thankfully, there is some excellent, and free, brewing software available that takes the guess work and technical aspect out of adjusting brewing water chemistry - so with a little bit of research into what is already in the water you use to brew - you can simply enter some numbers into an app, select a desired beer style, and the software will tell you what you need to add to your brewing water. Simple!

Finding out what's in your brewing water

Before we begin you need to find out what's contained in the water you're using to brew. You can use reverse-osmosis water and start with a blank slate (pure water with no other minerals/salts etc present), or if you're using town water, your supplier will hopefully have water reports available.

If your brewing water is good enough to drink out of the tap without tasting horrible, then that is a pretty good start and you can "build" your water profile from there, which is what I do.

I'm very fortunate living in Sydney, as Sydney water post the results of their water analysis every quarter which has a break down of the key components of water necessary for home brewing. This is specific to my address and is displayed after searching for it on their website.

An example water report showing key components of drinking water

Here are the key elements you should be looking for;
  • Total Chlorine
  • pH
  • Calcium
  • Sodium
  • Sulphate
  • Iron
  • Magnesium
  • Chloride
  • Alkalinity

If any of these values are given as a "range" - then make a note of the average value. Here's a brief breakdown and explanation of each of the core components in a water report.


Chlorine is used to disinfect water supplies to kill microbes that may cause disease. For the purpose of home brewing it is bad and not required. Thankfully it can be easily removed using campden tablets which are cheap, fast acting and effective.


pH is a scale used to determine  how acidic or non-acidic (alkaline/basic) water is. The scale runs from 0-14. 7 is considered neutral. Anything less than 7 is considered "acidic" and anything greater than 7 is considered basic/alkaline or non-acidic. Generally in terms of beer and brewing, we want slightly acidic and generally in the range of 5-6. Water needs to be slightly acidic in brewing to help breakdown the sugars from grains and malts during mashing.


Correct levels of calcium in brewing water can lower pH (ie. make more acidic), help preserve mash enzymes, increase the amount of sugars extracted from grains during mashing (the yield), and improve yeast health.


Sodium is generally referred to as salt. It has no chemical effect in brewing water. Can contribute to the flavour of beer by enhancing it's sweetness but is not generally added unless the particular style you are brewing calls for it.


Used to increase the perceived hop character of your beer and can help accentuate bitterness. Increased levels can lead to a perception of a drier and cleaner finish.


Not required for brewing - low levels less than 1mg/L are fine.


Small amounts are required for mashing. It helps to decrease mash pH.


This is different to chlorine or chloramine. Helps to accentuate a fullness or roundness of flavour in beer and especially enhances malt sweetness.. Concentrations in excess of 200 ppm can give a full malty taste and can help to enhance mouth feel.


A measure of the ability of a solution to resist (buffer) a change to it's pH value when acids are added.

What do I use to adjust my water chemistry?

When starting out, I recommend using the following four (4) items to adjust your brewing water. Just using these will make a huge difference to the taste of your brewed beer. They are also cheap to buy, and you generally won't need to use a lot in each brew, so what you do buy will likely last a long time.

Campden Tablets

Also known as potassium or sodium metabisulfate, a half tablet can be used to treat an entire batch of brewing water and will almost instantly remove chlorine or chloramine from your water. Crush it up before adding to make it more easily dissolved. I use a half tablet in mash water and another half tablet in sparge water.

Calcium Chloride

Calcium adds to water hardness and chloride accentuates maltness, sweetness and fullness. This is added to reduce mash pH to make it more acidic.

Magnesium Sulphate (Epsom Salt)

Similar to calcium sulphate but is not as effective as calcium in reducing mash pH. Can be used to add sulphate crispness to hop bitterness. Too much can have a laxative effect.

Calcium Sulphate (Gypsum)

Adds permanent hardness to brewing water. Helps accentuate hop flavour.

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