For how long can I leave the water in my French press?

QUESTION:

When making coffee in a French press, is it okay to leave the water in with the grounds for an extended period of time? I ask because I refrigerate my coffee for the next morning and I like it strong!

ANSWER:

Well, that's not what I would do if I wanted a great cup of gourmet coffee each morning. Making coffee in a French press only takes a few minutes, and you'll get a better cup of coffee by starting a fresh brew.

The problem with leaving the coffee grinds in the water for too long is that all the oils finally seep out of the coffee grinds and into the water. This gives your coffee a bitter taste.

It's for this reason that most brewing systems (think of the classic drip brewer) have water flowing through the coffee grinds and into a carafe. The water stays in contact with the grinds for long enough to extract their flavor, but not so long that all the oils are transferred, resulting in that bitter flavour.

As for a strong cup of coffee...that's easy to deal with when you use a French press. Just add more coffee, or grind the coffee finer. Using a finer grind is a perfect way to get stronger coffee from the same amount of beans.

For more information about the various elements involved in brewing great coffee, read our page on how to make coffee.