Treating Sydney tap water for pale ale

Sydney is one of the easier brewing cities in the world for water, and most brewers here never think about it. That is mostly fine. Our supply is soft — low in calcium, low in sulphate, low in carbonate — which means it will not wreck a beer the way a hard, alkaline supply can. But soft water is a blank page, not a finished one, and there are two jobs worth doing before you brew a pale ale with it.

First, get the chloramine out

Sydney Water uses chloramine rather than free chlorine for most of the network. This matters more than it sounds, because the folk wisdom about chlorine does not apply. Leaving water to stand overnight will not remove chloramine. Neither will boiling it — chloramine is far more stable than chlorine and survives a rolling boil comfortably.

If chloramine is still in the water when yeast gets to work, it reacts with phenols produced during fermentation to form chlorophenols. You will taste them at vanishingly small concentrations, and they are unmistakable: plastic, medicinal, like a sticking plaster. Once they are there, nothing removes them.

The fix is trivially cheap. One campden tablet — potassium or sodium metabisulphite — treats roughly 75 litres. Crush it, stir it into your full volume of brewing water, and give it five minutes. The reaction is effectively instant. At that dose the sulphite contribution is far too small to affect flavour or your yeast.

A carbon filter also works if you have one plumbed in, but it needs a slow flow rate to strip chloramine properly. A tablet is more reliable and costs a few cents.

Then, decide what the beer should taste like

Once the chloramine is gone, you have soft water with very little mineral content. That is a good starting point, because it means whatever you add is what you get.

Two ions do most of the work in a pale ale:

• Sulphate pushes bitterness forward and makes the finish drier and crisper. It is why Burton-on-Trent became famous for pale ale.
• Chloride does close to the opposite — it rounds the palate, makes malt read as fuller and sweeter, and softens perceived bitterness.

Neither is better. They are a dial, and the ratio between them is what you are setting. A rough guide that works:

• Crisp, bitter, hop-forward pale ale or West Coast IPA — lean toward sulphate, around 2:1 or 3:1 sulphate to chloride.
• Soft, hazy, juicy modern IPA — lean the other way, 1:2 or so toward chloride.
• Balanced pale ale — roughly 1:1 and let the malt and hops argue it out themselves.

You adjust sulphate with gypsum (calcium sulphate) and chloride with calcium chloride. Both are cheap, both dissolve readily in the mash, and both bring calcium with them, which you want anyway.

Calcium is the one you should not skip

Sydney water is low in calcium, and calcium does several useful jobs at once. It helps mash enzymes work, it drops mash pH slightly toward the range you want, it helps proteins coagulate in the boil so you get a better hot break, and it encourages yeast to flocculate cleanly at the end.

Aim for somewhere between 50 and 100 ppm calcium. In practice, for a 23 litre batch, that usually means a few grams of gypsum and calcium chloride combined, split between mash and kettle. You do not need to be precise. The difference between 55 ppm and 75 ppm is not something you will taste; the difference between 10 ppm and 60 ppm is.

What you can safely ignore

Plenty of water advice is written for brewers dealing with hard, alkaline supplies where mash pH genuinely fights them. In Sydney, with a pale grain bill, mash pH usually lands in a workable range on its own. If you are brewing something very pale and very light — a pilsner, say — a small acid addition can help. For a standard pale ale, it is rarely the thing standing between you and a better beer.

Reverse osmosis and building water from scratch are worth doing eventually, but not first. The order of impact for most people is: temperature control, then yeast health, then water. If you are still fermenting warm in the laundry, adjusting your sulphate ratio is not where your beer is losing points.

A workable starting recipe

For 30 litres of Sydney tap water, brewing a standard Australian pale ale:

• Half a campden tablet, crushed, stirred through, five minutes before you start.
• 4 g gypsum and 2 g calcium chloride, added to the mash.
• Nothing else.

That gets you clean water, adequate calcium, and a mild sulphate lean that suits a hoppy Australian pale. Brew it, taste it, and move the ratio next time based on whether you wanted it drier or rounder. That single comparison will teach you more than any water calculator.

Bring a sample in if you want a second opinion — and if you are chasing a particular commercial beer, tell us which one. Water is usually the last five percent, but it is a real five percent.