WEBVTT - BrainStuff Classics: Why Does Microwaved Coffee Taste So Bad? 0:00:01.920 --> 0:00:06.440 Welcome to brain Stuff production of I Heart Radio. Hi 0:00:06.519 --> 0:00:09.680 brain Stuff, I'm Lauren vogel Bomb and this this is 0:00:09.680 --> 0:00:13.080 a classic episode from our archives. In this one, we 0:00:13.160 --> 0:00:15.960 explore a question that's near and dear to my heart 0:00:16.239 --> 0:00:20.320 because I love the taste of coffee. So why does 0:00:20.520 --> 0:00:26.439 microwaved coffee taste so bad? Hey, brain Stuff, Lauren volke 0:00:26.520 --> 0:00:30.000 Bomb Here. Hot coffee is supposed to be hot. Cold 0:00:30.000 --> 0:00:32.440 coffee is supposed to be cold, and that's the deal. 0:00:32.800 --> 0:00:36.280 It's pretty simple. The problem, then, with hot coffee is 0:00:36.320 --> 0:00:38.599 that you can't drink the whole cup while it's at 0:00:38.600 --> 0:00:41.720 the optimal temperature unless you're willing to really guzzle it. 0:00:42.560 --> 0:00:44.800 So when it gets cold, you've got a few choices. 0:00:45.240 --> 0:00:48.280 Drink it cold, reheat it, or just pour that cup 0:00:48.280 --> 0:00:50.440 down the drain and start over with a fresh pot. 0:00:51.120 --> 0:00:53.880 All three of these approaches are either perfectly fine or 0:00:53.960 --> 0:00:58.000 completely barbaric, depending on whom you ask to Some hot 0:00:58.040 --> 0:01:01.480 coffee that's gone cold is revolting to others. The reheating 0:01:01.520 --> 0:01:05.640 process renders it completely undrinkable, but that doesn't stop us 0:01:05.680 --> 0:01:08.880 from occasionally popping a cup of nine hour old office 0:01:08.959 --> 0:01:11.600 Joe into the microwave at four pm to power through 0:01:11.680 --> 0:01:17.000 until bedtime out of some combination of desperation and mild masochism. 0:01:17.319 --> 0:01:21.039 Research into why reheating this humble drink is pretty much 0:01:21.040 --> 0:01:23.760 non existent, but it most likely has to do with 0:01:23.800 --> 0:01:27.560 our sense of smell. Humans aren't great at separating our 0:01:27.560 --> 0:01:31.920 gusta tory that's taste and olfactory that smell responses, and 0:01:32.080 --> 0:01:35.200 coffee has aromas and flavors that hit all five of 0:01:35.200 --> 0:01:37.360 the tastes that can be picked up by your tongue 0:01:37.400 --> 0:01:42.240 and other mouth and nasal passage nerves sweet, salty, bitter, sour, 0:01:42.400 --> 0:01:46.160 and savory. So your personal sense of smell has a 0:01:46.200 --> 0:01:49.240 lot to do with how coffee tastes to you, whatever 0:01:49.280 --> 0:01:53.520 it's temperature, and however that temperature was achieved. That's because 0:01:53.560 --> 0:01:57.520 the chemical makeup of coffee is astoundingly complex. Even though 0:01:57.520 --> 0:02:00.960 its reputation relies heavily on the presence of caffeean coffee 0:02:00.960 --> 0:02:05.200 gets its flavor from around a thousand different chemical compounds. Also, 0:02:05.400 --> 0:02:07.760 the final flavor of the coffee you enjoyed this morning 0:02:08.000 --> 0:02:10.880 was the product of a dizzy ng array of variables, 0:02:10.919 --> 0:02:14.320 including the temperature and weather conditions the beans grew under. 0:02:14.680 --> 0:02:17.600 When the beans were harvested, how they were dried, stored, 0:02:17.639 --> 0:02:20.920 and roasted, and how they were ground and brewed. So 0:02:21.200 --> 0:02:24.440 while the compound three methyl buttinol might make your cup 0:02:24.480 --> 0:02:27.600 of joe taste a little caramel like and ethyl no no, 0:02:28.000 --> 0:02:30.560 it may give it some fruity or notes. Each step 0:02:30.600 --> 0:02:33.760 of the process either brings out or suppresses any one 0:02:33.800 --> 0:02:37.960 of these aromatic compounds differently, which brings us to reheating. 0:02:38.919 --> 0:02:42.120 We spoke with Christopher Hendon, a postdoctoral fellow at the 0:02:42.200 --> 0:02:45.280 Chemistry Department at m I T and author of Water 0:02:45.360 --> 0:02:48.520 for Coffee, a book about how coffee interacts with water. 0:02:49.160 --> 0:02:53.079 He said reheating coffee in principle can be an absolutely 0:02:53.080 --> 0:02:56.800 fine approach to achieving a tasty beverage. In practice, this 0:02:56.919 --> 0:03:00.079 is not usually observed because people reheat in ways to 0:03:00.160 --> 0:03:04.000 promote the loss of delicious volatile compounds, and so the 0:03:04.040 --> 0:03:07.680 process of heating, cooling, and heating again drives smelling and 0:03:07.720 --> 0:03:12.000 tasty compounds out of the cup. According to Hendon, coffee 0:03:12.040 --> 0:03:14.200 experts seem to prefer a drink that has been brewed 0:03:14.280 --> 0:03:17.919 within the previous five to twenty minutes. It turns out 0:03:18.080 --> 0:03:20.600 most people prefer the coffee as it cools to around 0:03:20.639 --> 0:03:24.040 a hundred and fifty degrees fahrenheit that's sixty five degrees celsius. 0:03:24.639 --> 0:03:26.800 This has to do with the way our taste pathways 0:03:26.840 --> 0:03:30.040 respond to temperature in our food. But when we put 0:03:30.080 --> 0:03:32.240 something in our mouth that's too hot or too cold, 0:03:32.480 --> 0:03:34.880 we can't detect all of the compounds that contribute to 0:03:34.880 --> 0:03:38.280 its flavor. Since coffee has loads of these compounds, the 0:03:38.320 --> 0:03:42.200 temperature of the drink can affect the taste. Brewing the 0:03:42.240 --> 0:03:46.040 coffee brings out certain aromatic compounds, but whether the cooling 0:03:46.080 --> 0:03:50.040 process changes the chemistry seems to be controversial. Hendon says 0:03:50.120 --> 0:03:53.160 it is absolutely benign, while others claim it makes the 0:03:53.240 --> 0:03:56.040 drink more acidic as the coffee is exposed to air 0:03:56.160 --> 0:04:00.280 and oxidizes. Reheating coffee to the same temperature it was 0:04:00.320 --> 0:04:02.640 when it was first brewed might help you reach that 0:04:02.720 --> 0:04:06.000 sweet spot temperature wise, but it also has the potential 0:04:06.040 --> 0:04:09.480 to cause additional chemical reactions that further alter the flavor. 0:04:10.200 --> 0:04:12.680 And if you're reheating coffee that already has milk or 0:04:12.680 --> 0:04:16.599 sugar in it, that's even more in the way of flavors, proteins, chemicals, 0:04:16.640 --> 0:04:21.360 and compounds to contend with. So although many coffee connoisseurs 0:04:21.440 --> 0:04:23.640 will tell you it's a lost cause once your coffee 0:04:23.640 --> 0:04:26.800 goes cold. Others say it's just important to reheat your 0:04:26.839 --> 0:04:29.679 coffee as slowly as you can in order to prevent 0:04:29.720 --> 0:04:34.000 additional chemical reactions. But if you're reheating in the microwave, 0:04:34.240 --> 0:04:37.120 don't worry about ghosts of past foods heated in that 0:04:37.200 --> 0:04:40.680 microwave coming back to haunt your coffee. Hand And said, 0:04:41.000 --> 0:04:44.920 the concentration of the volatile chemical composition of say, splattered 0:04:44.960 --> 0:04:47.799 pasta sauce, is pretty low, so I would be surprised 0:04:47.839 --> 0:04:50.479 if we could attribute the bad taste of microwaved coffee 0:04:50.480 --> 0:04:54.720 to only that. Our advice crank your microwaves power down 0:04:54.720 --> 0:04:57.760 to or lower and sap your cup of coffee in 0:04:57.920 --> 0:05:01.719 thirty second intervals to prevent does faster. But of course 0:05:01.960 --> 0:05:09.880 we encourage you to run your own experiments. Today's episode 0:05:09.920 --> 0:05:13.040 is based on the article hand Signs Explain why microwave 0:05:13.160 --> 0:05:16.159 coffee tastes so terrible on how stoffworks dot com, written 0:05:16.160 --> 0:05:18.720 by Despolin Shields. Brain Stuff is production of I Heart 0:05:18.800 --> 0:05:20.880 Radio and partnership with how stuff works dot Com, and 0:05:20.920 --> 0:05:23.880 it's produced by Tyler Clang. Before more podcast It's my 0:05:23.920 --> 0:05:26.920 heart Radio, Visit the I heart Radio app, Apple podcasts, 0:05:27.040 --> 0:05:28.799 or wherever you listen to your favorite shows.