How many times can you safely microwave a cup of coffee before you have to abandon it and make a fresh one?

How many times can you safely microwave a cup of coffee before you have to abandon it and make a fresh one?

You can check the answer of the people under the question at Quora “how to heat up coffee without a microwave

0 thoughts on “How many times can you safely microwave a cup of coffee before you have to abandon it and make a fresh one?”

  1. Once.
    After that, your coffee-saliva mixture isn’t going to taste particularly fresh and you are either going to have to force it down or simply pour it out. Neither is the way to deal with good coffee.

  2. Depends on where you’re from.
    One classic story in my family:
    SIL-equivalent’s GF tosses an entire pot of coffee down the drain. It was yesterday’s.
    My BF and his son gasp. It was a whole pot of coffee! It was made fresh yesterday! We have a microwave!
    His son says, “Maria, coffee doesn’t grow on trees around here!”
    Maria is from Costa Rica, where coffee very much grows on trees. Everywhere. And no-one drinks yesterday’s coffee.
    (Added later: larger question, apparently ignored: what is going on with a person and a life that you simply aren’t drinking the darned coffee in the first place? Get an insulated cup already!)

  3. When I was in high school I would often get home and be hungry. I’d grab a frozen burrito and go to put it in the microwave only to be thwarted to find my mother’s coffee cup still in there. I’d nuke it for 45 seconds or so and bring it to her. More often than not she would tell me that she had poured that cup of coffee first thing in the morning and proceeded down the forget, remember, nuke cycle all day. One cup. Innumerable trips on the microwave carousel. She would then drink it. Sometimes she’d find that, in addition to the cup in the microwave she will have forgotten one or two others around the house.

    Based on that? How many times are you willing to nuke a cup of coffee? That’s your answer.

  4. Coffee s̶n̶o̶b̶s̶ aficionados may gasp at horror at my answer, but I can detect no difference in the taste of microwaved coffee.
    Yeah, the laws of physics exist at my house, so my coffee goes cold after it has been sitting for a while. It’ll sit there for hours sometimes after I just take a few sips, so I nuke it to warm it up. I think it tastes practically the same as when I first made it.
    I’ve nuked a single cup four or five times. I think it tastes fine.
    I don’t think safety enters into the equation (assuming we’re talking about only one day). Even if you put milk into your coffee and a few little nasty bacteria starts to grow, I think nuking the coffee takes care of them (if they were ever an issue in the first place).
    Anyway, I do this all day long and have never gotten sick or minded any real or perceived change in flavor.
    I’m sure others will be along to disagree. Please write an answer, rather than do it in the comments. Thanks.

  5. I think it depends on whether or not you have milk in your coffee. If you do, then the question is more about how long the coffee has been out. I tend to get worried around hour 5-6 if the coffee is in my thermos (actually Contigo brand) to-go mug. If I just have it sitting out, probably 3 hours or 2 microwaves (whichever is first).
    Because I sip on my coffee slowly all day between patients, I have to keep it warm without wasting time to go to the microwave, and so I spent an exorbitant amount of money on these things called Coffee Joulies

    How many times can you safely microwave a cup of coffee before you have to abandon it and make a fresh one?

    These little beans store some of the heat from your freshly brewed coffee and release it into the coffee over the course of about 5-6 hours. They really only work with a vacuum sealed thermos type container and all of the liquids have to be hot going in. So I heat up my milk and add freshly brewed coffee and for 6 hours in my Contigo mug I have hot coffee, it is pretty warm for about 8 hours.
    If there is no milk/creamer, then I agree with Garrick Saito about unlimited nukes but still the water gets stale after a few hours (probably 4-5 in an open mug, but much longer in a closed travel mug).

    Victor Allen’s

  6. I quit eating microwaving food over a decade ago. To me, once is one time too many. Then again, I only rarely drink coffee now, and much prefer sodas and iced tea.

  7. Safely? As long as you aren’t putting milk or butter in it, as often as you want, potentially until there is nothing but burnt, dried out remains in the bottom of your cracked cup.
    Enjoyably? My answer is less than once.
    The aromatics of coffee dissipate with time. Freshly roasted beans, freshly ground and freshly brewed make for an excellent and flavourful cup of coffee. Every step away from that freshness reduces the potential excellence of the coff…

  8. For me, the answer would be zero times. I try not to drink coffee that has been kept warm for more than 15 minutes. The essential oils are so volatile. If you don’t notice the difference, it might be that the oils in your coffee had gone off before you brewed it.

    Eight O’Clock

  9. OMG what are ya doing? Just looking at it? Or drinking it? No worries about safety aside from the aformentioned cream or milk eventually starting to go bad after a day.
    But taste? Every minute that passes after brewing the coffee starts to oxidize and the flavour changes.
    The main coffee chain in Canada is Tim Hortons and they specify 20 minutes after brewing is the maximum amount of time to maintain ideal freshness. I have had coffee from gas stations and convenience stores that I swear was brewed yesterday and it tastes horrible.
    A good friend of mine can nurse a cup of “Timmy’s” for 8 hours with multiple zappings.
    The microwave will introduce no danger or safety issues with the coffee. Zap away as many times as you like.

  10. Although I will occasionally nuke coffee that has cooled too much, I find that using a Contigo spill-proof mug (14 oz tho they go up to 20 oz) will keep my coffee sufficiently hot for hours. I can increase this time further by filling the mug with very hot water and letting it stand for a few minutes before filling it with coffee.

  11. 0… I don’t think reheating the coffee would get it go bad, but it would make it too bitter to be tasty (I read it somewhere, but have not done any experiment).
    Also, as other people have mentioned, it really depends on how long had the coffee been left for… And if it has milk or soymilk in it. Please be very careful if that is the case, because you don’t want a food poisoning (proteins that went bad can be VERY toxic).

  12. Regardless of whether I am a coffee snob, or a aficionado, or a tyro, I have to coffee to enjoy and savor the flavor, as much as I have it to stay awake.
    And nuking it does make it feel less aromatic.
    Does is really make my coffee less tasty? Perhaps no.
    But does it make my coffee less enticing? Hell yeah!


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