Suddenly, bad coffee

October 10, 2009 1:01 PM

I have a Cuisinart coffee maker that went from making good coffee to making undrinkably bad coffee overnight. Why is this, and can we fix it?

Things we have tried:
1. Open a new bag of beans. That's not it.
2. Clean out the coffee grinder as well as we can. That's not it.
3. Make coffee on our Aeropress. That tasted fine, so we're pretty sure it's not the beans or grinder.
4. Clean out the coffee maker with vinegar and water. No help.

The coffee the machine produces just tastes awful. My wife describes it as bitter and metallic, and she says that it has a slightly sandy consistency to it.

Our guess is that there's a dead bug in there, although we don't have any evidence of that. The machine (a Cuisinart model) is snap-together plastic mostly, and doesn't lend itself to disassembly, as far as we can tell. But if the only alternative is replacement, there's not much to lose.

posted by adamrice to food & drink (8 comments total)

It seems like you've covered all your bases, but...
If you're using tap water to make the coffee, what are the chances that the tap water has changed recently? It's doubtful this is the cause but if the water has changed taste that might be part of the problem, although that doesn't fit with the consistency. You could also go buy a jug of bottled water and try making coffee with that, see if that affects the taste at all.
Do you know if there is any metal on the inside of the maker that would come into contact with the water? Perhaps there is some rust?
You cleaned it with vinegar and water, was it pretty nasty? If so, did you try cleaning it again?

Those are my best guesses ... if you have nothing to lose, I'd take a tiny screwdriver to it and think about getting a new maker, but that's just me, and I like disassembling things :D
posted by neewom at 1:10 PM on October 10

What's the specific model of your coffee maker? Because we have a Cuisinart in our office that has basically done the same thing. Ours probably isn't the same as yours - the machine is plastic, but the carafe is metal - but we've found what looks like either burnt coffee or coffee-stained rust or at least SOME kind of deposit at the bottom that we can't get out. We've always rinsed and dish-soaped the carafe, but apparently that wasn't enough. Anyway, it's to the point where we've ordered another machine that's a little easier to maintain. So, there's something to consider. Maybe there are some deposits in the machine somewhere that are caked on so hard they can't be removed by the usual cleaning methods.
posted by katillathehun at 1:18 PM on October 10

I would try filtered/bottled water, and also a proper cleaning solution (like Cafiza or Cleancaf); they're no more expensive than vinegar and will do a more through job. Also make sure you're rinsing very, very well after cleaning, any residue will definitely impact taste. Brew the test coffee directly into a clean cup instead of the carafe, if possible.
posted by bizwank at 2:05 PM on October 10

Hmph. I was all set to tell you about the algae bloom that has been making some folks' water taste yucky, but if things taste better through a different maker, well, I don't know. But it seems like too big a coincidence to not mention, so there it is.
posted by dirtdirt at 2:56 PM on October 10

Thanks, all. I'm confident that it's not the water. Our tap water tastes fine, and we just did a taste comparison of tap water vs tap water run through the coffee maker. There's a clear difference. There's also stuff being trapped in the filter that is clearly not coffee-related, although it's not identifiable, either.

And while cleaning deposited crud is a good idea, I don't think it'll address this problem, which cropped up literally overnight. One morning our coffee was fine, the next it was awful.
posted by adamrice at 3:10 PM on October 10

mr. crankylex says the heating element is probably going, causing lower brew temperatures and an under-extracted cup of coffee. The brewed coffee should be at least 194 degrees right after it comes out, if it's less than 190, the heating element is shot.
posted by crankylex at 4:15 PM on October 10

I think your machine has a clogged water filter. On my kinda cheap cuisinart if the filter is spent/clogged up it just bypasses and all the junk thats been collecting on it end up in the coffee. Yuck.

If you have a filter it's probably under the lid where you pour the water in. I hope this helps!
posted by snsranch at 5:08 PM on October 10

+1 on the heating element; coffee brewed at too cold a temperature extracts all sorts of off tastes. If you have a cooking thermometer, try looking at the temp of the just brewed coffee (or if you have one with a probe, see if you can put the probe in the brewing basket while it's brewing). If the just brewed coffee is much under 185, or the temp in the brewing basket is under 195, it's brewing too cold.

If this is the case, you might be able to limp along awhile longer by pre-heating the caraffe, and using hot water for your brewing water, but it's probably time for a new brewer.
posted by nonliteral at 5:25 PM on October 10