A great many folks buy coffee and dump in random amounts (i.e. eye-balling) to their machine, put a number of cups of water in and...hope for the best....?
Aside from the most important tool in brewing coffee, there is one more item that is (luckily) MUCH less expensive to get ahold of.
Even if you don't have the means to grind your beans fresh. The tool you really need is a kitchen scale (that measures in grams).
The main problem with the way many of us make a cup of coffee is that we use random amounts of coffee and water. This results in cups that are sometimes good, sometimes not so much. And if you use copious amounts of creamer (no judgement!), then you likely don't notice. But even with creamer, you would likely notice a difference in your cup if you brewed with exacting amounts of coffee and water.
This concept is known as the coffee to water ratio. Simply put, how many grams of coffee you use to how many grams of water you use to brew that cup.
Typical coffee to water ratios are between 1:15 to 1:18 (that is, 1 gram of coffee to 'x' grams of water, depending on how strong of a cup you want). The standard you'll likely see at most coffee shops is 1:16.
When you brew outside of these ranges, things can taste too strong, too weak, weird, unpleasant, inconsistent, and will leave you wondering why.
You might say, "well, I can use the marking on my carafe to measure how much water in cups (ounces)" and then use a tablespoon to measure my coffee. While this is possible, you should know many coffee machine manufacturers use different definitions for a "cup" of coffee. This ranges anywhere from 5oz all the way to 8oz...this can throw off your ratios if you do not know how many ounces your coffee machine manufacturer use to define their markings on the carafe...this is why its still best to get a scale so you can know exactly how much coffee and water you are using.
Get ahold of a kitchen scale (as little as $15 on Amazon!) that measures in grams and start measuring exactly how much coffee you're using and then use the proper ratio of water and experience the difference in consistency and quality! Once you find a ratio you like, you can easily repeat it (or experiment if you like). Another perk of having this type of scale is that it is one of the first steps in getting into pour over coffee (a brewing method where you have ultimate control of the qualities of the final cup).
Typical amounts of coffee for various serving sizes at a 1:16 ratio are below:
1 person (about 8oz) = 15 grams of coffee to 240g water
2 people (about 14oz) = 25g coffee to 400 grams of water
4 people = 40g coffee to 640g water
Wondering how to convert to ounces? There are ~28g per 1 oz.
For stronger cups, use more coffee OR use less water. Too strong? Use less coffee for the same amount of water OR use more water.
Try it out!
Best,
Percussive Coffee