Coffee brewing has simple fundamentals: combine coffee grounds and water. Exactly how to combine these is a question with many answers, kind of like asking how fast one should drive: the answer will not be a specific speed, but rather a flexible set of guidelines that help you determine the answer for each context. Similarly, dialing in a coffee recipe on your equipment to your preferences is a matter of trial and error that will take experimentation to get the tastiest results. Note that optimal recipes can vary from different beans, roast levels, resting times since roast and more. How much experimentation, and how far you dive into home brewing, is entirely up to you.
How much ground coffee do you need? This is a broad question with many correct answers, depending on preference and equipment.
If you want a basic, easy starting point, use 2 tablespoons of ground coffee per 6-8 oz of water.
However, using a simple kitchen scale to measure the weight of coffee and water will increase your consistency from brew to brew.
Generally, when coffee professionals and enthusiasts use a scale, they describe a recipe as a ratio and measure in grams (g). A ratio like 1:16 describes the recipe, which in this case means each gram of ground coffee needs 16 grams of water. Similarly, 20g of ground coffee would then pair with 320g water, as an example for a single cup recipe at this ratio.
Coffee professionals recommend 1:15 on the strong end and 1:20 on the weak end for standard American drip coffee preferences. Consider a stronger ratio if pairing with cream or milk.
Note that this is for drip/filter coffee brewers; methods like espresso (1:2-3), French press (1:11-15) or cold brew (1:6-16) will vary. Consult your brewer’s instructions or website for their recommended brew ratios and grind sizes.
Freshly ground coffee is the biggest improvement you can make if you are currently using pre-ground coffee. Oxidation, when coffee meets the oxygen in the air, ages coffee and changes the aromatic flavors we can extract from the bean. Grinding increases the amount of coffee exposed to oxygen while also releasing some aromatic particles into the air that will not make it into the brewed cup.
As important as a fresh grind is, getting the right grind for the job is important, too. Just like consistent knife cuts are important for cooking food evenly, consistent grind size is important for brewing a tasty cup of coffee. Otherwise, fine powders will over-extract and impart bitter qualities while bigger chunks will under-extract and deliver sour notes.
Burr grinders, as opposed to cheaper blade grinders, are key to this. Coffee beans are ground between rough burrs, which are set to leave a small opening for the coffee to pass through once it is the right size. Blade grinders, on the other hand, spin a blade around like a blender for a set amount of time, leaving particle size much more random and varied.
If you do not own a burr grinder, consider one of these Baratza grinders.
Which Grind Size?
Just like the other factors, there are many correct answers to this question that will depend on preference, equipment, and the coffee bean itself. Also, each grinder manufacturer has differently labeled settings that can even vary between versions of the same model. For a general starting guide, Kruve has created some reference charts here.
To estimate where your grinds measure, a printable PDF of Kruve’s BREWLER includes these particle sizes to scale here. Note that grinders will always produce a range of sizes rather than a set of perfectly uniform particles. Additional measuring tools and sieves are available through their website for further precision and tighter control over grind size distribution.
Once you have a starting grind size to try, make note of which grinder setting you use. If your brew time is longer than expected or tastes overly bitter/dry, try a coarser grind next time. On the other hand, if your brew happens too quickly or tastes overly sour, try a finer grind. On the same page as Kruve’s grind chart, they have also compiled a basic reference for coffee ratios and expected brew times.
Brewed coffee is mostly made of water, and the quality and temperature of water affects the final taste.
The temperature of water while brewing can be anywhere from cold to lukewarm to steam, depending on brew method and desired outcome. For most coffee brewed with hot water, the Specialty Coffee Association (SCA) recommends 195-205° F (90-96° C). If you do not have a thermometer, a kettle taken to boil then removed from heat for 20-30 seconds usually falls within this range.
Water in its most pure form only contains hydrogen and oxygen, and filtration methods like distillation and reverse osmosis achieve this level of zero Total Dissolved Solids (TDS); however, some dissolved minerals are desirable. Calcium, magnesium, sulfur, carbon, sodium, potassium, and more can be included to change perception of factors like bitterness, acidity or body. Some municipalities have tap water that is already nearly ideal for coffee brewing, while others will need filtering and/or remineralization.
Various companies offer mineral blends that can be added to distilled water. You can compare coffee brewed using this water and your home water to see if water composition is an area you can improve. For further information, the SCA has posted guidelines here and here.
A special thanks to our friends at Kruve for giving us permission to use their graphics above.