I've written this before, but it's come up again recently so I thought I'd go over it one more time.
As far as I'm concerned there's no actual secret to good coffee; just chemistry, and learning how not to screw it up.
Good coffee is made with good water, in good properly roasted beans, at the right temperature, for the right amount of time. That's it.
Coffee is one of those things that's simple, though simple, doesn't necessarily mean easy.
Coffee beans are EXTREMELY sensitive to temperature, moisture, and PH. They have a lot of volatile organic compounds that react with these different elements. Too little, and you don't get the flavor out. Too much and you either burn the flavors out, or leech out flavors you don't want.
So, what exactly does good water, in good beans, for the right amount of time etc... mean?
Well, how about I share some tricks with you.
- Make your bean, roast, and grind, fit your brew, and brew method. There is no perfect bean, perfect roast, or perfect grind. Each type of coffee (everyone has something they like, or don't like) and each brewing method, requires a different roast and a different grind.
- Use filtered water, not distilled. Distilling water removes all the trace elements and dissolved solids that give it character and flavor, making it taste flat. Filtering gets rid of chlorine (which absolutely ruins coffee), sediments, and most of the excess mineral content; but leaves enough minerals for the water not to taste flat.
If you must use distilled and it does taste flat; put a half teaspoon of sugar, a half teaspoon of salt, and a half teaspoon of baking soda in each gallon, and dissolve them thoroughly before brewing. That will "wake up" your water.
Also, a TINY bit of vinegar, or lemon juice, in the water produces a slightly better cup of coffee. Call it a drop per cup. Lowering the PH just a bit helps in the extraction, and helps disperse the oils.
- A pinch of salt per cup added to the grounds makes a MUCH better cup. Again, it helps in extraction and dispersing the oils. It also acts to enhance your tastebuds perceptions of other flavors.
- The best results are with beans roasted 7 days or less before you brew. Some beans are great just after roasting and cooling (never grind while beans are still warm); some require anywhere from 12 hours to 5 days of resting before achieving peak flavor.
There are local roasters almost everywhere these days, but it may not be convenient to use them. If you have to get prepackaged beans, make sure they are vacuum packed, and the roast date is no more than 6 months before you intend to use them.
If, god forbid, you use preground coffee; you can significantly improve it by simply regrinding it for a few seconds just before brewing. It breaks up the surface of the grounds, allowing more essential oils to express. Obviously this only works with relatively coarse grounds (chock full'o'nuts and Yuban are quite coarse. Maxwell house is finer).
In any event, you should grind just before you brew, or at most a few hours before (the night before to preprogram your machine for the morning let's say). Otherwise some of those volatile oils will evaporate off, leaving you with less flavor.
- Two level tablespoons of medium-fine grounds per 6oz water is ideal for any immersion brew (including automatic drip machines); but will produce a very strong and robust brew from all but the thinnest of coffees.
Reduce the amount slightly to 2 tablespoons per 8oz for a slightly less strong brew; but don't reduce to below 1tblsp for every 6oz.
- If using an auto drip machine, pre wet the grounds with a spray mist of tepid or cold water before hand, and you'll get more even extraction.
- Never brew at above 208 degrees, or below 190 degrees Fahrenheit; unless you are cold brewing.
Unfortunately the average coffee maker barely hits 190 degrees at the showerhead. You need a high end commercial machine, or a machine like a Technivorm, which will get the water to 205, but NOT to burn the coffee on the warming plate (actually, some Technivorms don't even have a warming plate).
The best way to guarantee proper temperature water is with a french press, or a pour over filter; preferably decanted immediately after brewing (or brewing directly into) into your cup, or a thermal carafe.
- Never immersion brew for less than about 2.5 minutes, or more than about 4.5 minutes actual extraction time. You don't get the full flavor with less than 2 minutes immersion. After around 4 minutes at heat, the oils start to become unpleasant tasting, and more tannins are leeched out of the ground beans.
- If you're going to apply any kind of warming, make sure it's below 160 degrees, and for no more than 15 minutes after brewing. Any hotter, or longer, and the oils will start to go rancid.
- If you want good coffee from a noncommercial machine, run a bare water cycle through first; then when the machine is heat soaked, run a brew cycle. Never brew with hot water though, as it can contain more dissolved sediments that can ruin your coffee.
Honestly, you don't have to be so fussy. Just remember brew about 2tblsp per cup, of a medium ground coffee, at between 190 and 208 degrees, for between 2.5 and 4.5 minutes, using filtered water.
The rest, that's optional, or to compensate for problems, or to really get that last bit of flavor etc... etc... Just plain good coffee, that's simple.