Thursday, 17 April 2014

How water affects beer flavour

It is often said that the balance of sulphate and chloride affects beer flavour, but I haven't seen any evidence to support this. Until that is I dug out a paper from 1981 by Dr David Taylor titled: How Water Composition Affects Taste.

Reading through it my heart sank when I read the line: "Contributions made by various ions are well known, if somewhat empirically." Oh dear I thought, here we go again. Sulphates make beer dryer and enchance bitterness, chlorides make beers sweeter, etc. as I've seen before in other sources. But where's the evidence? Then in the tables that followed there was some. A weak lager and ale were made and analysed for flavour on a scale of 0-5 then compared with different salt additions. 

The salt additions are high but I still found it interesting seeing the effects quantified. 

Differences in taste scores for 1033° lager plus 100ppm chloride as calcium and sodium salts (original beer 180ppm SO4 ions, 200ppm Cl ions)
Flavour + CaCl2 + NaCl
Sweet +0.4 +0.6
Bitter +0.2 +0.2
Metallic -0.5 -0.3
Salty +0.5 +0.5
Body +0.6 +0.5

Drying -0.4 -0.4
Mouthcoating +0.5  0
Bitter 0 0
Metallic -0.2 -0.5

Differences in taste scores for 1038° ale plus 200ppm chloride and 200ppm sulphate (original beer 200ppm SO4 ions and 300ppm Cl ions)
Flavour + CaCl2 + CaSO4
Sweet +0.1 -0.5
Bitter -0.5 +0.2
Metallic -0.8 +0.3
Salty +0.1 +0.3
Body +0.8 -0.8

Drying -0.6 +0.8
Mouthcoating -0.3  -0.8
Bitter -0.1 +0.6
Metallic -0.1 +0.6


  1. "well known" = couldn't find (or couldn't be bothered finding) any references. I jest. This is neat. The additions do seem high, but then the base beers are fairly well loaded already aren't they?

  2. I been reading loads on brewing water recently so it's well known to me anyway! In fact I've got a stack of water stuff on my desk at the moment. Here's an online reference if you haven't seen it:

    And you're right the salts seems fairly high all round.

  3. That was a dig at Dr Taylor rather than at you. See also this kind of thing.

  4. Have you read the Water book by Palmer and Kaminski? Like everything brewing, taste is subjective. Water chemistry tends to have more effect on mash pH than flavour.

    1. Yes, it 's a good book but could have done with being editied down a bit. The pH thing about carbonates and calcium levels is pretty clear but I'd still like to see more stuff about chloride/sulphate levels as well as balance.