Do I have to bother with using filtered water in a standard coffee maker?

Question

Since the water is boiled into steam which collects at the top and then goes through the coffee & filter, isn't only distilled water going through at that point?

Answer 1

You only really have to use filtered water if you have very hard tap water with a lot of minerals in it. The minerals can collect in the coffee maker, making it take a VERY long time to brew. It's not exactly distilled water going thru your coffee maker, because not every mineral is dissolved into the steam.

Answer 2

Your standard run-of-the-mill coffee maker uses an inline heater and a check valve. The water flows down through the check valve into the inline heater, where it is heated to the flash point. The steam then blows the boiling water up out of the pipe into the coffee basket, emptying the pipe. When the pipe is empty, the cold water in the tank flows by gravity through the check valve and refills the inline heater. If you put hot water in the tank, the inline heater is much too powerful. It is designed to take a certain amount of time to heat up a load of cold water, but when it encounters hot water it will heat it up in no time and pass the water through to the coffee basket faster than it can filter it.... overflowing basket, water everywhere, and weak coffee. There will also be a lot of steam and rattling - after discharge the inline heater is still hot, until the cold water cools it off. Then it heats up the cold water until it is hot enough to flash. Imagine, though, what happens when hot water drops onto a hot heater - it flashes immediately and explosively, blowing water and steam out with some violence. You could certainly design a coffee maker to run on hot water - all you have to do is put a much, much weaker heating element in it. In fact, commercial coffee makers do use a tank of preheated water - when you push the button it just drops the hot water at a measured rate through the basket.

Answer 3

You don't have to use filtered water. But distilled and filtered are 2 different things.

Any heavy metals in your tap water could be trapped in your coffee maker. But I wouldn't worry about it; the coffee maker will probably crap out before the deposits clog the plumbing.

Answer 4

I think the largest reason is that the water quality could affect the taste of the coffee and/or lime can eventually clog it up.

I haven't ever used filtered water and haven't ever had an issue.

Answer 5

Depends on your tap water. coffee is 99% water so the better tasting the water the better the coffee will taste.