Brew Your Perfect Cup
Most people ask "How do I make the perfect cup of coffee?". Really the answer to that question is "How ever you like it is the perfect cup." This isn't really a helpful answer since it depends on the coffee origin, roast, brewing method whether you prefer dark or light roast etc.
I strive to be helpful, so maybe a different question is in order which is "How do I make the coffee I prefer over and over again?"
It's all about the coffee to water ratio. So break out your calculators and kitchen scale and let's do some science.
Coffee to Water Ratio
Measurements
What you need to replicate is the amount of coffee to water (by weight) you use to make your perfect cup. In other words the amount (grams) of coffee to amount (grams or mL) of coffee.
Ratios are expressed like this:
grams of coffee : grams of water
So if you have a ratio of 1:18, you would use 1 gram of coffee for every 18 grams (mL) of water.
Common ratios are:
1:18 (Light)
1:17 (Regular strength)
1:15 (Strong)
Notice that the lower the second number, the stronger the brewed coffee.
Why metric units?
Because 1 gram of water equals 1 mL of water - so it makes the math work out easier. Of course, once you have the weight proportions for the brew strength you like, you can always then convert to ounces, cups and tablespoons.
How to Measure
Start with the amount of water
12 fluid-ounces of water is approximately 355mL of water. Since 1 mL of water is 1 gram, 12fl-oz of water, you have approximately 355 grams of water.
Next weigh the coffee
If you want a 1:17 ratio, divide 355 by 17, to get approximately 21 grams of coffee. Use a food scale to weigh out the coffee, then add the 21g of coffee to your brewing device with 12 oz (355g) of water and brew it up.
To help experimenting I've added this chart where I've done some of the math for you.
Have Fun Experimenting
Experiment and take notes. Once you find what you like measure out the coffee in tablespoons and then you can make your favorite cup over and over again.
Different brewing techniques yield different coffee experience, so brew 1:17 in a drip coffee maker, will taste different than the same ratio made say in a French press.