Hard water is high in dissolved minerals, largely calcium and magnesium. When hard water is heated, such as in a home water heater or in an espresso machine, solid deposits of limescale (mostly made up of calcium carbonate) deposits itself in any and all components where water flows through.
Signs of limescale buildup include:
1. taking longer to heat up the water and consuming more energy in the process
2. clogging and narrowing of water pipes
3. machine break down completely
4. coffee tasting off
If you've noticed any of these signs, perhaps it's time to give your water tank some loving maintenance, a good clean with some descaling liquid, puly caff detergent and prevention of calcium build up with a water softener.
Singapore's water mainly comes from rainfall and recycled waste water, and is considered relatively soft at an average of 64ppm (parts per million, or mg/L). However, this is not consistent across the country and depending on where you live, it can range from 24ppm to 148ppm (source: PUB).
As a comparison for our neighbours & overseas buyers, Malaysia has a national standard of 225ppm, and if you get fresh water saturated with minerals from the mountains, can get measurements of up to 350ppm or more. This means that coffee drinkers in these countries use more water softener per L of water compared to a coffee drinker in Singapore, where the same quantity of resin softener will last 3x or more water.
The Lelit softening resin utilizes Ion exchange to remove all hardness minerals by swapping the calcium and magnesium ions in water for sodium ions. The strong acid cation resin softener is great for drinking water and preventing limescale buildup in ANY espresso machines with a tube in the water tank to connect the resin. This process does not remove chlorine or any sediments in the water.
However, while we try to prevent buildup in our espresso machines, removing hard minerals from your water entirely results in a flatter, less flavourful coffee profile. Hence, the SCA recommends levels of 60ppm and a study by Carr recommended levels as low as 30ppm for optimal flavour extraction.
We hope this shows the impact of one small component of water on flavour for home brewers and to encourage beginners on your coffee journey. Coffee extraction continues to be both an art and science as we work with the many, many different factors which affect the final drink.
Other cleaning materials for machine maintenance:
Cafetto Espresso Machine Cleaner:
Puly Milk Steam Wand Cleaner:
Puly Grinder Cleaner: