How Important Is Water Temperature When Brewing Coffee?
If you've switched to manual brewing at home, you know that there are a few things to nail down in order to ensure a good cup. In this column, we have previously discussed the importance using freshly roasted beans, getting your grind right, and figuring out the right water to coffee ratio. All of these things are part of ensuring that you end up with the best cup possible. But if you've got the beans, the grind and the dosage right, there's one more thing that's crucial to a good cup of coffee: water temperature.
The Importance of Extraction
You can't make coffee without water, because water is what draws out the flavor from the coffee grounds; what's referred to as extraction. Water temperature is essential in this process, because if your water is too hot, you risk an over extraction, leaving the coffee tasting bitter, and if your water is too cold, you can risk an under-extraction, where the coffee is weak, and maybe even tastes sour.
Of course, there are methods of brewing that use cold water, but because that is an entirely different discussion, for the sake of simplicity, here we are talking about brewing hot coffee.
The Best Temperature for Extraction
According to the National Coffee Association, 195°F to 205°F is ideal for optimal extraction. But water's boiling temperature is 212°F, and that range is actually in reference to the brew temperature — in other words, when the grounds and water are together. So what does this mean in real terms that will help you brew a better cup at home?
Verve Coffee Roasters put together a great video last year to explain the importance of water temperature in brewing (which I found very helpful), and I got in touch with them to learn more.
I asked Macallie Atkinson of Verve Coffee Roasters to help us understand the influence of water temperature on coffee brewing just a little bit better.
First off, 195°F to 205°F is the range where water-soluble flavor compounds most easily dissolve in water. Go too hot and you over dissolve them, go under and they won't dissolve as easily. Which is why when you are brewing coffee at home, it's essential that you stay in that range.
There's no way of getting around this. "If you are going to spend the time, energy and most importantly, money on making good coffee at home, these parameters are vital to your success based on the scientific research that the SCAA as well as several other foundations have conducted," says Atkinson.
If you watch the Verve video, you will see that as long as you are within this range your coffee is going to taste pretty good. As Atkinson says, "the 'optimal' way to brew at home is to simply use whatever method you prefer to bring water to a boil... and to control every parameter as best as you can."
It might be easy to think that one element of coffee brewing is more important than another — i.e. grind over dose — but Atkinson points out that it's important to look at coffee brewing as a whole. "I don't look at the components of coffee in the shape of a pyramid, rather in the shape of a circle, where no part of the process is complete without the other. Quality coffee is useless without proper brew temperature. Grind size is important, yes, as well as with dosage, but non of those variables matter when exposed to improper water temperature," says Atkinson.
In fact, water temperature might is probably the thing that most people tend to forget. "Too often times do I find that water quality is being overlooked entirely. Your coffee is only as strong as its weakest link," says Atkinson.
What's the Best Way to Control Temperature?
But what does all this mean for you the home brewer? There are temperature control kettles out there, but Atkinson recommends "to get more for your money, I suggest you buy a decent thermometer and then you will have added a valuable piece of equipment to your entire kitchen, not just your coffee arsenal." If you are using a thermometer, you want to measure the slurry — the mass of coffee grounds and water that collects at the top.
If you are brewing with a Chemex or a French press, it's also a good idea to pre-heat the vessel, simply by pouring hot water in it. Water temperature "is definitely a control variable that must be paid attention to, mostly due to the fact that the water does cool off during longer pour over or brew times like the Chemex or French Press," says Atkinson.
I know there are some of you readers out there that are thinking "Isn't this a bit extreme all for my morning cup of coffee?" Whether or not you invest in a thermometer is up to you; some people take more pleasure in being precise than others. But if you aren't looking for precise measurements, rest assured that bringing water to boil, then letting it sit for just a little bit before you pour it over the grounds will keep you in that sought after range.
Do you need to worry about water temperature when brewing coffee? Definitely, yes. But how much you worry about it, and how precise you get is going to be up to you. You can brew a good cup without a thermometer, but if you want to bring precision to your brewing routine, where you are 100% sure to brew a solid cup every single time, then it could be a smart investment for you.
What Makes a Good Cup of Coffee
Ultimately, it's important to remember that a good cup of coffee is the result of a variety of elements; good beans, grind, dosage and water. If you are going to invest the time and energy in brewing a good cup, you can't skimp on one of these angles.
So while you don't need to drive yourself crazy about getting an exact water temperature to the tenth of a decimal place, you do want to make sure you're not pouring boiling water on your beans, and on the flip side, that you're not pouring boiled water that has been sitting on the counter for 30 minutes.
At the end of the day, remember this: good beans deserve a good brew.