Water is the number one subject people ask about. Water is the solvent that brings for the oil from the grounds. Without water, there’s no coffee. Learning about water and how to view it helped me enormously to brew better coffee. As in most things coffee, there are lots myths surrounding water. I want this to be short and sweet. Here’s my quick opinionated practical guide to brew great coffee.
“Hard water won’t extract because it’s already too full of minerals.”I hear it all the time. Don’t think of water as absorbing coffee oils. Think salad dressing. Oil and water don’t mix. Think of heated water being a solvent that removes coffee oil from the grounds and they get mixed into the hot water, making the beverage known as coffee. Also, when water is heated the minerals go into suspension. They are virtually unimportant during brewing. What minerals do is add taste. The reason not to use highly mineralized water is they risk adding a flavor that competes with or clashes with your coffee flavor. If that’s not reason enough, hard water suspended during heating, cools and hardens on the insides of your coffeemaker’s plumbing. It doesn’t take much to clog your coffeemaker’s arteries and interfere with the flow. This causes everything from substandard brewing temperatures, to slowing down brewing to simply halting the process. A coffeemaker manufacturer’s repairman once told me the majority of their service was simply calcium-choked coffeemakers.
If you have highly mineralized water, you should do the following: Drink some. If it tastes good, you can brew coffee with it. If the water doesn’t taste good, you shouldn’t brew with it because it will flavor your coffee, almost always it will taste bad. For bad tasting water use bottled water. For very hard water, you can choose. If you are willing to routinely be running vinegar or Urnex (a good coffeemaker cleaner) through your machine, and use fresh water (better still distilled or low-mineral bottled water) to rinse afterwards, you can continue to use hard water. But consider if your water is hard enough, you won’t save much by just switching to bottled water, compared to buying vinegar, coffeemaker cleaner and bottled water to rinse the machines.
If you use bottled water, check to see that it is low enough in minerals to make a difference. Usually it is lower simply because most bottled water manufacturers do some filtration to make their products consistent… but not always. Some bottled waters are full of minerals and not even any softer (meaning lower in mineral content) than the hardest tap water. The most reliable waters for brewing coffee are so-called drinking water, which are usually highly filtered municipal waters. Most often, they are treated with reverse osmosis filtration, which all but eliminates minerals. Then, the water bottler adds some particles in controlled amounts, just enough to add ‘normal’ flavor – water with no minerals can taste ‘flat’. There are some excellent good-tasting bottled waters, both low in minerals and with good taste that are not r/o filtered, but they take a little patience to find.
Under no circumstances should you use softened water, meaning water that’s been treated with a home water softener. Actually, there is an exception – espresso machines sometimes benefit from softened water, but these are dedicated machines and it’s a special case. I’m still not certain I fully approve of it, but at least it qualifies as a possibility – with espresso. This is not true using drip, vacuum or press pots. Softened water is especially problematic with automatic drip machines, where softened water and ground coffee can combine to make gelatinous goo that will become stuck in your brew basket.
Softened water is virtually undrinkable anyway due to its elevated sodium content. I anticipate the question of alternate softening methods. To be honest, I don’t know, nor do I know if it’s been researched by anyone. I’m eager to learn if any tests have been done.
So, there are the coffee basics you need to brew great coffee minus the myths.