Does Water Quality Affect the Taste of Your Coffee?
Selecting the right quality of water matters a lot. And while the quality of water varies throughout regions of the world, filtered and tap water are commonly used to brew coffee as they are easily available in most places.
But it’s not just a case of whether hard water (high PPM) is bad and soft water (low PPM) is good. What actually matters is what the dissolved solids are and what they’re doing to the brew that really matters.
Depending on your location, your tap water will have a different mix of minerals such as calcium, magnesium and sodium which will determine whether the water is higher in minerals (hard) or distilled (soft).
When it comes to coffee, roasted beans are full of compounds like citric and lactic acid and eugenol (and we know that you know that dear coffee barristers!) which exist in different variations- giving it complex and varying flavours. Water itself is complex with varying levels of calcium and magnesium which affect the taste of your coffee – and therefore your life…
It’s What Inside That Counts
Magnesium and calcium generally make up the bulk of dissolved solids in water and both are beneficial to extraction. Magnesium tends to bring out fruitier more acidic and delicate notes, whereas calcium brings out more chocolatey, creamy, heavy notes. It is important to have a balance of both these minerals when brewing coffee, however, in specialty coffee softer water with higher levels of magnesium is preferred to help promote and nurture complex acidity.
Some hard water compounds tend to be sticky and hang onto compounds in your coffee. If eugenol hangs around, your coffee will have a ‘woodsier’ taste. While magnesium is a sticker compound that delivers a stronger cup of java. Water with a high level of bicarbonate may render a bitter cup of coffee.
High magnesium (hard water) can produce a stronger, more flavourful coffee compared to softened or more distilled water.
Achieving Perfect Water for Coffee
There are various filtration methods used by high-end specialty coffee shops to get softer water. Here are a few of the methods with their pros and cons:
- Reverse osmosis (RO)
- While RO is a popular filtration method used, it can be expensive. A semipermeable membrane removes unwanted particles and chemicals with more expensive models being able to remineralize the water with important minerals. Without remineralising the water with magnesium and calcium, coffee can end up tasting flat. (Lack of magnesium and calcium however is good for machine health though.) Another downside with RO systems if that for every 1 litre of filtered produced, 1 litre of water with filtered minerals is wasted.
- Calcium Treatment Unit (CTU)
- This is a popular and more affordable filtration system with the aim to remove calcium thereby preventing a build-up of limescale in your equipment. From a long-term cost perspective, this saves you money, as limescale build-up over time can cause major damage to your coffee making equipment, and therefore damage to your life! A con of CTU’s is that they filter a certain amount of minerals and still produce relatively hard water.
- Magnesium-Enriching Filter
- One of the latest additions to the coffee offering at Climpson and Sons, original East London Coffee Roasters, is the BWT magnesium enriching filter called Bestmax Premium.
