Making a good cup of coffee can be a remarkably difficult thing to do sometimes, because people just don’t get taught how to do it properly. Even a lot of baristas working at coffee shops don’t know how to make a proper cup of coffee.
I have formal barista training, as well as being a coffee drinker, so I know a good coffee when I taste/smell one.
Coffee Fact 1:
No matter what sort of coffee you’re making, the water should NEVER actually be at boiling point (100°C). This will burn the coffee, and give it that horrible sour aftertaste. To make the ideal coffee, the water should be between 88 and 94°C. This is hot enough for the coffee to release its flavours quickly, but not hot enough to burn it. A good way to make sure of this at home is to let the kettle cool for a couple of minutes before you pour the water into your coffee cup.
Coffee Fact 2:
You know that creamy, light brown layer that ends up on top of a well-made shot of coffee from an espresso machine? That’s called the crema. It’s formed from the oils in the coffee beans. Something most people don’t know – even instant coffee gets it. If your coffee (instant or otherwise) does not end up with crema on top, the water is too hot and the coffee has been burnt. The crema is what gives all the complex flavours to the coffee.
Coffee Fact 3:
Soy milk is very difficult to get the proper creamy foam required for a good latte, as it does not contain the fat and proteins that help it hold. If your soy latte looks exactly the same as your friend’s full-cream one, you have a good barista. If it doesn’t, don’t complain – very few baristas (particularly at commercial coffee chains) are able to do a good job of soy milk. It also quickly crosses from “nice” to “burnt”, so avoid asking for your soy coffee “extra hot”, unless you know the barista is familiar with the ins and outs of soy milk.
Coffee Fact 4:
A latte should be served in a glass (not a ceramic cup). If it’s served in ceramic, technically it’s a flat white. The whole point of a latte is to get a 3-layer look. You should have a slightly lighter bit at the bottom, then the large “coffee” section, then a strip at the top that is made up of the cream. The top strip should be about one finger width at the most. This is what you should see when you look at the glass:
Coffee Fact 5:
Use the correct grind! If you use the wrong grind for the wrong thing, you will not end up with a nice cup of coffee. If the grind is too fine, the coffee will be over-developed and very bitter. If the grind it to coarse, the coffee will be very bland and under-developed, and will not have released the full flavour profile. Here’s an infographic about what grind to use for each preparation method:
Coffee Fact 6:
As also shown above, the amount of time works with the grind to give the best cup of coffee. If the grind is correct, but the coffee is allowed to brew/draw for too long, the coffee will still be bitter and awful. Too short a time, and it will be bland.
Coffee Fact 7:
Coffee should be kept cool and in an airtight container or it will go rancid. Whole coffee beans keep much better (and longer) than pre-ground, so if you have a grinder, grind only what you will use within 24-48hrs and toss it after this time. If you don’t own a grinder, buy only what you will use in the next week and keep it in the freezer. This isn’t GREAT for the coffee grounds, and can dry out the oils, but it still tastes better than letting them go rancid. I’d really suggest getting a grinder if you are making coffee at home with a machine or contraption. If you live in a particularly hot climate (like me), keep your beans in an airtight container in the fridge and use them within a month of opening the bag you bought them in.