Brewing the perfect cup of coffee is a huge feat and will require you to know your tools and personal preferences. You'll have to be a scientist, take notes as you go, pay attention to each cup, and decide what alterations you'd like to make after each coffee. In the words of Peter Drucker, "what can be measured can be managed". He was referring to the world of business, but we think it applies here nicely.
If you're a casual coffee drinker looking to kickstart the morning, you'll find these numbers to be valuable benchmarks when starting your day.
Keep in mind your equipment dictates how fine a grind and how hot your water needs to be. Once you've settled on your brewing method, the following decisions will become much more manageable. We'll get into grind consistency and water temperatures in a bit, but for now, let's explore some of the more popular brewing tools.
Drip coffee is the standard plug-in coffee maker you recognize from brunch with grandma. You'll need a fresh filter and a nearby outlet.
Chemex (Pour Over)
For the next-level coffee lover. This hourglass figure looks at home in a laboratory or your kitchen. Similar to most pour-over coffee makers.
Widely - yet arbitrarily - believed to be the best coffee-making method. Natural oils expose all the flavours and antioxidants the particular type of coffee roast has to offer.
Stovetop "espresso" maker forces steam through the fine grind to create small, concentrated coffee.
The coarser the grind, the longer the grind needs to be exposed to water to create delicious coffee (we'll go over brewing time shortly). Coarse grind, used in a French Press, will need between 6-8 minutes to brew. Drip and Chemex/Pour Over methods use a medium grind and will need 4-6 minutes to brew. Moka Pots use a fine grind and are brewed the quickest, usually between 1-4 minutes for a one-cupper.
Remember the blooming process (link to further down in the article) when using a French Press and Pour Over method. Forcing a bloom takes about 30 seconds and drastically change your brew for the better.
Coffee to Water Ratio
We're about to get technical.
When seeking how much ground coffee to use compared to the total volume of coffee brewed, a safe ratio for drip, Chemex/pour-over, and French Press coffee makers is 55 g/L (give or take 10%). According to the Speciality Coffee Association, this is the equivalent of 1 tablespoon* (~13.75ml) per 8.4 fluid ounces (250 ml). Nice and simple. Phew.
Things become complicated if you're seeking the amount of ground coffee needed to make X number of "cups" because there isn't a standardized or widely recognized measurement for a "cup of coffee" size. 5-6 fluid ounces (150-175 ml) are considered a cup in the USA. Meanwhile, you'd need 7-8 fluid ounces (210-235ml) in Canada and 6-7 fluid ounces (175-210ml) in Japan. If you've ever had coffee at my parents' house, you'd know a cup equal to a small bucket. There is just too much variance in accepted cup sizes to give a universal answer. This answer is entirely dependent on your brewing equipment and physical cup sizes.
* This equation uses tablespoons - a precise method for determining volume - to measure the mass of ground coffee - a substance varying in bean size, density, and grind coarseness. Despite being uniformly ground, two tablespoons of two different beans will produce different masses and interact with water uniquely. Using tablespoons makes mornings easier, but we should technically use a scale for measuring our ~13.75ml of ground coffee.
The ideal brewing temperature is about 200F (93C), so let your boiled water sit for a few minutes before pouring into your drip, Chemex/pour-over, or French Press. Scalding hot water will burn the grind (and your oesophagus), turning a full-body coffee into a bitter substance.
Moka Pots are a bit different. The water in the bottom chamber needs to boil for the coffee to brew. A trick for quicker, better-tasting Moka Pot coffee is to boil the water before pouring it into the bottom chamber. Since most Moka Pots are made of aluminum, an incredible heat conductor, the entire contraption can quickly become dangerously hot. Should the upper basket become too hot, your coffee will burn. Boiling the water first will reduce the time your Moka Pot spends on the element.
Brewing time is entirely dependent on your equipment. Each of the following points assumes the water is already heated to ~200F (93C).
Once the water has begun dripping through the grind and paper filter, it takes about 4-6 minutes before you've got the most out of your beans.
French Press/Chemex/Pour Over
An oft-overlooked step is first to pour just enough water to wet the grind. This causes natural gases and carbon dioxide to escape in a process called "blooming". If you skip this step, these escaping gases will interfere with the water trying to extract all those flavours and caffeine. Do this small pour, wait 30 seconds for most of the gases to escape, then pour the rest of the water.
Using a gooseneck spout kettle for a Chemex/pour-over is the most effective way to wet all the beans and get a uniform brew. After the bloom, fill the top portion with water and let it pass through the filter. You should be good to drink in 4-6 minutes.
If you're using a French Press, fill the console with your desired amount of water (after they bloom) and let it sit for 6-8 minutes before filtering and pouring.
This one's simple. Your coffee is done if the pot is gurgling. The brew time is dependent on the size of your Moka Pot and the stove element setting. We recommended setting the element to medium-high. You shouldn't have to wait more than 5 minutes for a one-cupper.
There are so many variables when creating your "perfect" cup of coffee. Even if we had a perfect piece of equipment, water temperature, grind coarseness and weight, accurate kettle, and universal coffee cup size, we'd still be at the mercy of different roasts and even the ever-important final factor, personal preference. No amount of precise calculations or perfectly-timed steps could make me drink green coffee!
Use all of these stats as starting points in your brewing adventure and pay attention. Experiment with different aspects and see what works best for you and your palate. This is your time to be a scientist, and we promise the rewards will be worth it!