It’s the age old question of wannabe home Baristas everywhere, what is the perfect temperature for coffee? A good cup of coffee doesn’t just happen; you have to work for it. Many different variables like quality beans, fresh grounds, proper grind size, uniformity of grinds, grind to water ratio, quality of the water and of course the temperature of water all work together to produce the ultimate brew. Scientific research carried out by SCAA (Specialty Coffee Association of America) and other independent bodies confirm that all of these factors are vital to how good your cup of Joe turns out. Considering the fact that coffee is mostly water, it is surprising that most people tend to ignore it the most!
Water is the component that drawthe aromas and flavours out of the coffee grounds; without it there is no coffee! The temperature of the water is a cardinal component in the process of extraction. This is because if the water is too hot, over extraction will result, producing coffee with a burnt taste that is bitter. If on the other hand the temperature of the water is on the low side, grinds will be under extracted and the coffee will turn out weak and perhaps somewhat sour. Like so many things in the world of coffee, there are no hard rules; some people like iced coffee while other take theirs extra hot. Luckily, there are a few guidelines and best practices that can help you brew the perfect cup for you and your guests.
Ideal Coffee Brewing Temperature
Let’s start with the ideal temperature for brewing coffee. There tends to be this general perception that hotter/longer = better when in fact, most experts agree that the ideal temperature for brewing coffee typically ranges from 195 °F (91 °C) to 205 °F (96 °C) with the best results achieved closer to 205.
You’ll notice that neither of those temperatures is above the boiling point, and there’s a very good reason for that. Although it feels counter-intuitive, boiling water is actually detrimental to your coffee. While coffee has many wonderful things we want to extract, there are also certain unpleasant elements which will add excessive bitterness, burnt notes, or other undesirable characteristics. If you use boiling water to brew your coffee (admit it, we’re all guilty of this one) you’ll begin to release these undesirable compounds and will actually burn the coffee as well, which will all show up in the flavor! With that in mind we can begin to think of brewing as a balancing act where we want to sufficiently heat up the coffee to a point where we’re extracting all of that goodness, but not so much that we start getting the bad as well. We want those bad elements to stay in the grounds!
Luckily, the laws of nature have been watching your back. Water boils at about 212 °F (100 °C) which is very close to our ideal temperature and experiments have shown that simply removing the water from heat and pouring it into another container (like a coffee mug) will almost instantly reduce the water to roughly 203 – 205 degrees. In fact, those tests were done with pre-heated glass vessels so if you’re transferring your water directly into a French press, mug, or some other vessel which hasn’t been preheated, the water may cool down further to roughly 197 degrees! The main take away here is you don’t need to worry too much about the ideal temperature of water, you may actually see much better results just from preheating whatever vessel your coffee is about to be poured into!
Similarly, if the temperature of the water is too low we’ll also be left with an inferior final product. As you can probably imagine, this has the opposite effect of brewing too hot or too long. When our water temperature is too low the water cannot properly extract all the oils, aromas, and flavors you’re hoping to get out of a premium cup of coffee. As such, you end up with a taste that’s flat and unexciting.
If you plan to use a Chemex or French press to brew your coffee, you need to account for the cooling down of the water during the brewing process. The cooling down effect of water can be minimized by preheating the brewing vessel. Just add hot water to it and allow the carafe to heat up before using it for brewing.
Best Temperature for Serving Coffee
So we know how hot the water needs to be when we’re preparing a cup of coffee, but what about when we’re finally ready to serve it to guests? What is the ideal temperature for serving coffee? Well, as you can imagine, this will depend on several factors such as your guests’ personal preferences and what type of coffee you’re serving. With all that said, a general rule of thumb is that coffee should be served somewhere between 155 °F (68 °C) to 175 °F (79 °C) with most people preferring it at the higher end of that range. You should keep in mind that some specialty coffees call for a lower serving temperature so always follow the directions.
It’s also worth noting that some coffee experts prefer to drink their coffee much cooler, closer to 130 °F (54 °C); which would feel downright tepid to you or I! One noted coffee tasting expert George Howell has been tasting coffee for more than forty years and he prefers his drink closer to 130 ºF. He purportedly said that the lower temperatures allowed the drinker to experience the subtler tastes found in the coffee which simply could not be enjoyed at the near scalding temperatures of the average cup of coffee. His logic makes perfect sense. Temperatures of around 175 ºF are hot enough to burn your tongue, and it would be hard to taste much of anything at that stage! If you do happen to buy some specialty coffee, you might consider trying it out at lower temperatures next time.
Coffee Brewing Explained
The reason coffee temperature is so crucial comes down to a few different factors you might not expect.
Grind size is another factor that can influence how good your final cup of coffee is. I’ll try to spare you the science lesson but basically, how effectively the water can extract the coffee flavor is dependent on surface area. Think of it this way, if you were to put one solid cube of coffee into hot water, it likely wouldn’t work out too well. That’s because the water can only break down the 6 outer walls of the cube; the center of the cube won’t be touched until the outer walls are gone. But if you cut that cube in half making 2 cubes, suddenly you have 2 extra walls you can work on at once. Cut those two cubes in half once more and you’ve added an extra 4 walls. Keep doing that until you end up with cubes the size of individual coffee grains and you’ll begin to understand why grind size is a factor.
So the extraction process gets exponentially easier as the grains get smaller, so the finest grinds are the best right?! Wrong! Again, it’s all about balance and the issue is that finer grinds make it easier to accidentally extract those undesirable compounds we discussed earlier. In fact, in the Spanish village where my father grew up, the local coffee master is known to adjust his grind depending on how humid it was that day! Remember, finer doesn’t necessarily mean better.
One other thing to keep in mind is that if you’re using bad water, you’ll end up with bad coffee. Most experts will tell you to use bottled spring water when brewing coffee, particularly premium coffee. Personally, this feels like a bit of overkill and I’ve found that municipal tap water filtered through my trusty Brita Water Filter usually does the job just fine. The one thing I wanted to mention on the subject of water is to avoid using soft water or distilled water. This is not advisable as these are missing the minerals typically present in water which play a big part in the extraction process.
Water to Coffee Ratio
The final consideration you’ll need to think about when brewing the perfect cup of coffee is just how much water and coffee to use. The golden ratio for coffee is roughly 2 tablespoons for every 6 ounces of water but keep in mind that this can be adjusted as needed according to special brewing instructions or personal taste.
Well, we’ve taken a look at coffee temperature and several of the other factors that go into brewing the perfect cup of coffee. Hopefully, this quick guide will help you get the absolute most out of your next cup!