When the idea of improving their coffee comes to mind, most people make the assumption that "better" coffee beans equal better coffee. And while this is true, your coffee beans' quality is only part of the picture when it comes to making your daily cup of joe taste better.
In this article, I'm going to breakdown the most important factors that play a role in brewing coffee - your beans, your grind, and your water - and how you can control them to improve your coffee quality.
One needs only to perform a side-by-side comparison of a cup of pre-ground store brand coffee to a cup of freshly roasted specialty coffee to understand the difference that quality coffee beans make. But, what is it about the beans that makes such a big difference? It's a gross understatement to say that the answer to this question is complicated. Countless books are devoted to terroir, farming practices, processing, and roasting. So, to keep things simple for this article, we're going to start at the end and look at how coffee quality is graded.
There are over 1000 compounds in roasted coffee that are responsible for its aroma and flavor. While not all of these are extracted in the brewing process, and far fewer are discernable to our palette, knowing this gives us a greater understanding of how different one cup can be from the next.
The Coffee Taster's Flavor Wheel by SCA and WCR (©2016) used under CC BY-NC-ND 4.0
When a coffee becomes available for trade, it's the job of a specially trained taster, called a Q grader, to visually inspect the coffee, identify the flavors by cupping, and assign a score to the coffee from 1 to 100. To be qualified as specialty coffee, it must score at least an 80 with a score of 80-84.99 being Very Good, 85-89.99 being excellent, and 90-100 being outstanding.
Once the coffee is in the roaster's hands, it's their job to pull out the beans' absolute best and faithfully represent the coffee's regional characteristics. But, when it comes to brewing your cup of coffee, having quality beans is only one piece of the puzzle. You also need fresh beans.
Immediately after roasting, the coffee holds a large (relative to its small size) amount of CO2 and other gases. These gases seep out of the bean over time, with much of it escaping in the first 24 hours. If brewed too early after roasting, these gases can contribute to an astringent flavor that would otherwise be undetectable. Some coffee professionals refer to this time as a "calming" or "resting" period.
After about a week, the chemical compounds that give coffee all those beautiful aromas and flavors begin to degrade. Depending on the roast level, coffee will become flat and stale after about 2-3 weeks. So, most coffee professionals will say that coffee is best brewed after 48 hours but before three weeks have passed.
A rough illustration of roasted coffee quality over time.
Note that the times above apply to whole bean coffee. Ground coffee degrades at a much faster rate (talking minutes, not days) due to the larger overall surface area. That's why it is absolutely best to buy whole bean coffee and grind it as close to the time of brewing as possible.
Perhaps the most significant variable that you have in your control from coffee to coffee is your grind. There are two aspects of grinding that are important to consider when brewing - ground surface area and ground resistance.
If you remember from your high school geometry class, surface area is the sum of areas of all surfaces of a three-dimensional shape. Generally speaking, the larger the shape, the larger the surface area. But when we are talking about breaking that shape into smaller components, the opposite applies. The smaller the individual pieces, the larger the surface area of all pieces together becomes.
This is an important concept to remember when extracting coffee. Simply put, as surface area increases, so too does extraction.
Another way of thinking about this is in regards to the individual particle size. When water comes into contact with coffee grounds, it must start from the outside and work its way in with each grind particle. So the smaller the particle, the more easily it can extract all of the flavorful compounds locked inside it.
This also comes into play when talking about coffee ground resistance. If you set two identical coffee drippers side by side, put coarsely ground coffee in one and finely ground coffee in the other, and pour water over both at the same time, which will finish draining first? It's like the difference between pouring water over large loose rocks versus pouring water over sand. What's important about this is that - applying what we know about surface area - the longer the water is in contact with the grind particles, the more it will extract.
Now, this all seems straightforward and simple to apply, but there's one more thing that throws a wrench into the mix: grind quality. It's impossible to get a completely uniform grind particle size. When you grind your coffee, you will get some grind particles that hit your target, but also some larger and some smaller.
It may be impossible to get perfect grind quality, but it is possible to improve it. The best way you can do this is by simply investing in a better grinder.
I'll be blunt at this point and say if you are still using a blade grinder, you're doing it wrong. Blade grinders work on the concept that the longer you grind, the finer the coffee will become. But, there is no way to ensure that all the coffee particles come into contact with the blades for the same amount of time. What you end up with is a whole lot of overly ground coffee dust, a slightly smaller amount of coffee boulders, and a tiny amount of coffee ground to the size that you actually want.
On the contrary, burr grinders work off of the concept of space rather than time. Within a burr grinder are two interlocking discs with sharp teeth. The distance between the two discs determines the particle size of the coffee.
This isn't to say that burr grinders are perfect. The fact remains that coffee beans are uneven. No matter the method you use, they break apart unevenly. So, even with the best grinder in the world, you will end up with some dust (fines) amongst your grinds.
At the end of the day, investing in a quality grinder will do more to improve the taste of your coffee than anything else you do. You'll have more control over your grind size and less variation in your grind quality.
Coffee is ~98.75% water, yet water quality is an oft-overlooked part of brewing coffee at home. It is not uncommon for cafés to spend thousands of dollars in setup, plus ongoing costs, to ensure their water is adequately filtered. Sure, part of the reason they do this is to protect the equipment they use from mineral buildup, but they also do this to improve the taste of their coffee. But many, if not most, people at home don't consider where their water is coming from and how it affects their cup's quality.
Minerals are found in every naturally occurring water source. The level of this minerality in our context is referred to as hardness. The harder the water, the more flavor it will have on its own, and while some of these minerals can be good for the taste of coffee, others are detrimental.
Chart detailing water quality standards by SCA. It is neither practical nor necessary for the average home-brewer to achieve this level of control over their water quality. But if you want to try, go for it! If not, I've got some tips below that will help you out without extensive testing.
In addition to minerality, municipal water supplies are chemically treated with chlorine to disinfect and kill germs. While this may not always affect the taste of the water itself, chemical treatment can affect the water's pH balance, which can, in turn, change how well your coffee extracts and tastes.
Before I dive into possible solutions, I first want to mention something that you definitely should not do. Don't use distilled water. As mentioned above, the minerality found in natural water sources can help the taste of your coffee when in the right proportions. Furthermore, distilled water, while not strictly bad for you, doesn't really help you out as much since it doesn't help replenish the minerals already present in your body.
Now, how do you improve your water quality without breaking the bank? I'm going to focus on what I think are the two most practical solutions: filtration and water supplements.
As I've already mentioned, water filtration is commonly used in cafés worldwide to improve their water quality. But these filtration systems are large and expensive for home use applications. That's where a filter like the PEAK Water Pitcher can fill the void. Unlike a standard filter, like Brita, PEAK filters are specifically for making your coffee taste better. It is a dual-chamber water filter that you can adjust to suit your water supply. It's easy to set up and use, but you have to replace the filters every couple of months.
If water filters aren't your style, water supplements are a compelling alternative. You simply add a mineral packet to a gallon of distilled water and mix it up. The end result is water that is perfectly suited for coffee brewing.
Either way, you'll end up with more evenly balanced water. So, as long as you do a good job of controlling your other factors, you'll end up with great coffee every time.
In many ways, brewing coffee is as straightforward or as complicated as you want it to be. But since you've made it this far, I'm going to assume that you're not satisfied with merely throwing grounds into a Mr. Coffee. The above information is just a primer on the vast amount of information available on these topics. But I hope that it helps you understand a little bit more about what goes into making an excellent cup of coffee.
I firmly believe that the best thing you can do is to experiment. Take the information above (or from one of the countless coffee professionals who are way smarter than me), and try out different brewing methods, coffee ratios, and grind sizes. Most importantly, just enjoy the end result - preferably with a friend.