Welcome to this new article, where I will talk about the importance of keeping coffee at an ideal drinking temperature, what this temperature is, how it influences the taste of the drink, how to maintain it and what to do in case the coffee loses temperature after brewing.
As I have already mentioned in other articles, we know that the ideal temperature for drinking coffee is between 50 and 60 degrees Celsius; beyond this range, the taste of the coffee will be affected. This happens because of the chemical changes in the coffee as time goes by; from before extraction until it cools down completely, the coffee progressively changes its flavours and aromas.
If we go to everyday life, many of us do other activities while preparing coffee to optimise our time. Still, despite so much to do, we may forget that the coffee was already ready to drink, and when we remember, it is already cold, so it doesn’t taste as good.
To avoid having to drink a cold coffee or throw it away because we no longer like it, I bring you two equally valid alternatives: to keep the coffee hot for longer and to reheat it if it has already cooled down. Below, I explain the best way to carry out each of them so you can decide what to do if this happens.
How to keep coffee hotter for longer?
As time goes by and the coffee cools down, more chemical changes occur that affect the beverage’s taste. There is a way to slow down these chemical processes a bit, which is to keep the coffee hotter for longer. This is achieved with the help of elements such as thermos flasks or cups that retain heat.
Once the coffee has been prepared and is still hot, you can immediately transfer it to the thermos or cup to retain its temperature. This way, whenever you want to drink hot coffee, you only have to pour it from the thermos or directly from the cup where it remains.
However, it is important not to exceed the time the drink remains in the thermos because if it spends too many hours in the thermos, the flavours can also change. The aromas cannot evaporate, and there will be condensation due to the chemical changes that are still present in the coffee.
How to reheat coffee after it has cooled down?
Let’s run out of time and forget to drink the coffee at the ideal temperature, about 50 degrees Celsius for me, or we don’t have a thermos to keep it warm. There is no need to throw the coffee away if you don’t want to, as you always have the option of reheating it.
Many do not approve of this alternative because the result has been a disaster, an unpalatable coffee completely ruined. However, maybe it is because they are not doing it right; following some recommendations, you will be able to enjoy a good coffee even after reheating it. The key to a good result is not overheating it and using the right brewing method.
What happens when coffee is overheated?
When we overheat coffee in any way, we are overcooking it. Every time the temperature rises, the acids are broken down, mainly chlorogenic acids, which are the ones that contribute to the bitterness of coffee, so the more we heat it, the faster all the remaining aromas and volatile compounds will disappear, as oxidation destroys them.
Some of the solid compounds dissolve again every time the coffee is heated again, but many others do not, which generates more astringency and less body in the beverage. This is why overcooking should not be overdone.
What is the right way to reheat coffee?
After doing a lot of research and despite many divided opinions on the subject, I can affirm that the microwave is the most suitable, if not the only recommended, tool for reheating coffee.
I can say this because, as I said before, the key to getting a good result when reheating is not to overcook. If you heat it directly on the stove, you will have to leave it longer to raise the temperature, and it may overcook. In contrast, in the microwave, you can quickly reach the ideal temperature (in about 40 seconds or so, you can reach 50 degrees Celsius).
NOTE: Remember that when coffee is oxidising, raising the temperature increases the oxidation, so the faster we can act, the better the result.
I also have to say that there is a lot of prejudice surrounding the subject of heating coffee in the microwave. Many claim it can even negatively influence health, insinuating that it is practically the worst thing to do, however, they are just that, prejudices and myths.