The Longest You Should Leave Water In A Coffee Maker Reservoir

So many of us can't get our day started without a (big) cup of coffee, and if you want to save yourself a few bucks, you'll make your latte at home. If a simple, strong cup of Joe is all you need, you don't have to invest in a fancy Nespresso; you can get by with a basic, straightforward coffee maker, or even the reliable, retro Moka pot. Should you opt for a regular coffee maker, you might like to save yourself a step in the morning by prepping your coffee the night before (and if you're really on the ball, you'll set up the timer). But what happens if you're in such a rush to get out the door you don't even bother running your coffee maker? Aside from the grounds, how long is the water good to sit in there? As it happens, it's not nearly as long as you might think.

Fresh (or what was fresh) tap water should only sit in the coffee maker for up to 24 hours before it should be removed, and filtered water has an even shorter window of about half that time. Now, if your water sits in the reservoir for even a few days, it's likely nothing bad will happen. But after two or three days, the liquid can start to change, breeding bacteria that can actually pose a hazard to your health. For that reason, it's best to get in the habit of using the water every day, or "losing" it by dumping it out.

While the fact that sitting water in the reservoir could eventually turn into a bacterial mess that would leave you heaving and gagging once you spot it is a completely valid reason to change the water after 24 hours, it's not the only one. There's a reason experts say that quality water matters when it comes to brewing coffee, and just as you might use filtered water instead of tap when you make your joe, the freshness of the aqua can have an equally significant effect on how your coffee tastes. You can tell when water has been left out to sit for a while; it starts to taste stale, and maybe even a little funny, thanks to the loss of oxygen from exposure to the air. Do you really want that coloring how your coffee — what some of us look forward to all night — tastes? We thought not.

Which leads us to how to dump out the old, unused water from your coffee maker. If you have a coffee maker without a detachable reservoir, it can be a bit awkward, but it's manageable. Remove the pot and the filter, and make sure the machine is unplugged. Carry it to your sink and tip it over on its side until all the water has run out. You might have to dab at it with some paper towels or a dish towel that you don't mind getting dirty to get any water remaining at the bottom that won't drain.