Ask LJ

[coraa]

This one is for the coffee aficionados, and in fact non-coffee-aficionados will probably find it very silly:

Does reheating coffee hurt its flavor? I'm asking because I've been experimenting with making cold-brewed coffee, and it tastes very nice and smooth, but I prefer a hot cuppa in the morning and I'd like to warm it up somehow.

The microwave is the obvious choice, but everything I've seen hollers at me to not microwave my coffee! Only every site that says that seems to be assuming that I would have made or acquired hot coffee, let it cool down, and then microwaved it, so they're really all saying "don't drink stale coffee," which is a different thing. This coffee is fresh and tastes wonderful, I just would prefer that it was hot.

Anybody know?

Comments

[porfinn.livejournal.com]

Just rooting around in my memory of such things, I believe heating coffee can hurt its taste (it seems all heat, even from the grinder, can upset the delicate beans feelings). That's one reason coffee snobs don't like drip coffee makers because the warming plate burns the oils out of the coffee, or something like that. Do you put sugar and cream in your coffee? If you do, then it won't matter too much if you heat it up unless your taste buds are really, really delicate. Charbucks always comes out ahead in taste tests that involve additions to coffee, but usually comes in last if the coffee has to be drunk straight (the tasters think it tastes burnt). I think warming it up in the microwave will not hurt the taste enough to bother you, especially if you are going to put stuff in it. And, of course, I think with coffee the true test is: what tastes good to you and what is most convenient. Try it. (but I would microwave it gently. Nuking it to a warm glow probably isn't advisable :)

[coraa.livejournal.com]

Thanks! I suspect that my coffee habit (always milk, sometimes also sugar) is such that any harm from microwaving would be unnoticeable, but I am curious in the general case. On the other hand, the flavor advantages of cold-brewing (the coffee has very low acidity, which is wonderful for my stomach, although I have to watch it/make decaf because I can drink low-acidity coffee much faster) probably counteract the disadvantages of microwaving somewhat.

[porfinn.livejournal.com]

I will try to find some more concrete details of the process, since I think you would find it interesting. Once upon a time I could spew forth this stuff with cliff notes (something in the reheating process changes the chemistry of the oils, or some junk that I can't remember at the moment), but it seems I have either freed up some room in my brain or fried those particular memory bits. Either way, it will be fun to refresh things. But now I must go play with the fishies!

[porfinn.livejournal.com]

"without" cliff notes. Poor brain. It's especially fried this morning. Doctors are annoying, but in a good way.

[bellwethr.livejournal.com]

Good morning!

What I've read about cold brewing suggests that you can cold brew a concentrated coffee, which you then dilute with hot water as needed.

[coraa.livejournal.com]

Oh, that's a good idea. Since I drink my coffee milky, I could dilute it with hot milk, too.

[willworker.livejournal.com]

Immersion heater?

Steve

[ceph.livejournal.com]

My reading on the subject concurs with bellwethr's--use cold-brewed concentrate with hot water to make an americano sort of beverage.

Here's a forum thread from coffeegeek (home of many coffee ubersnobs) with discussion on microwaving (starts a couple of posts in.)

I've also run across a theory that the problem with reheating coffee is overheating it, and that microwaves tend to heat unevenly thus spoiling the cup as a whole. So perhaps sufficiently gentle heat will do the trick without spoiling the coffee.

[coraa.livejournal.com]

I'm not sure that my taste buds are likely to notice the level of distinction that the people at coffeegeek will, but it's definitely interesting to know.

I'm thinking maybe making concentrate and diluting with hot milk would be ideal, since I like my coffee with milk anyway.

[ceph.livejournal.com]

You could do a blind taste test, just for curiosity's sake--make one mug of coffee with cold-brew concentrate and hot water, then make another mug with cold water and heat it to more or less the same temperature in the microwave, then get someone to mix them up and see if you can tell which one has the iocaine powder was heated in the microwave.

[bellwethr.livejournal.com]

Ooh, I like the idea of a blind taste test!

[ceph.livejournal.com]

I think this calls for a Coffee Science Party.