By the time I come home from work in the morning, a pot of coffee that was brewed by others in my house (and is still quite full) is slightly too cold by the time I am able to drink it. I don’t want to waste the resources or time brewing a fresh pot, but the coffee always tastes “off” when I microwave it. The flavor is also much worse if it is reheated after cream is in it, but even black coffee leaves much to be desired. What are the best practices for reheating coffee?
Cold-brewed coffee heats well. Hot-brewed coffee that is old (whether on the warmer for hours or allowed to cool) will have pronounced flavors that most drinkers find unpleasant.
If you are concerned about wasting grounds, either brew smaller batches of hot-brewed coffee, or look into cold-brewed coffee. Most groceries carry pre-made cold brew or cold brew concentrate (read the labels to see if added water or milk is recommended), or consider getting a brewing container to make at home in the fridge. It stays good for 7-10 days once brewed so you can purchase or make a week's worth at a time.
Heating it up on the stove top on low temperature. This doesn’t require any special spoons or pots, (though there are some available for purchase), simply use any pot in your kitchen cabinet.
If you are sure to keep it on low temperature, you don’t have to hover over it and constantly stir it with a spoon. This way, you can enjoy your coffee without literally frying away all of the flavor. But please, be patient! If you try to heat it up at a high temperature, it may burn the pot or taste like burnt liquid. Make sure you keep the temperature on low and don’t rush the process, because the only thing that taste worse than cold coffee is burnt coffee.
(Ideal Temperature to Drink Coffee help you test more flavors. )