The delightfully gray area continues as each coffee drinker has their own preferences and their own brewing method. While there is no substitute for trial and error, below are some basic guidelines and hints to help you brew the best cup of coffee possible:
Over-extraction. Generally, the longer the coffee grinds are immersed in hot water, the coarser the grind should be to avoid over-extraction. Why? Well, the longer you immerse coffee in hot water the more undesirable tastes are likely to emerge. If your preferred method has a long extraction time, using a coarser grind slows down the release of these unwanted bitter tastes. Specifically, we’re talking about bitter oils in the coffee that you don’t want in your cup. Simply put, coffee “flakes” trap those oils better and longer (though not indefinitely) while coffee particles release them fairly quickly.
So, espresso machines offer the most efficient extraction and get extremely finely ground coffee because the extraction time is very short-- ideally, between 20 – 30 seconds. (Note: If it’s taking less than 20 seconds to brew your shot(s), it will be weak and you should use a finer grind and/or compress or “tamp” the coffee down more firmly in the porta-filter. Conversely, if it’s taking longer than 30 seconds you will tend to get bitter over-tones and should try using less coffee first and if that doesn’t help coarsen the grind a touch.)
If you are brewing individual cups with a cone and paper filter (often referred to as the “melitta method”, then you will want to use a very fine grind (just a bit coarser than espresso grind.) The ideal extraction time for this method is 90 – 120 seconds. Note that this is one of the least efficient methods of brewing regular coffee but results in an extremely satisfying cup. (For this reason, it’s how we brew coffee at Dirt Cowboy Café.)
Most auto-drip coffee makers take between 2 to 4 minutes depending on the desired yield and the coffee maker. We actually recommend the grind to be finer than the one you get if you select “auto-drip” on a typical supermarket coffee grinder -- unless you are brewing large amounts of coffee at a time. Again, coarsening the grind is an attempt to inhibit the release of undesirable oils. If the coffee is coming out bitter, you should coarsen the grind. If it’s coming out too mild, select a finer grind next time.
I’m not at all ashamed to admit that I have had reasonably good coffee from percolators, despite the scorn heaped on them by many coffee “aficionados.” The grind should be pretty coarse though. And you know, there’s really something wonderful about that coffee bubbling up into that see-through top. And the sound of percolating coffee is sooooo soothing!
Finally, French Press. Some people don’t mind a little coffee grind at the bottom of their cup-- sort of a romantically bohemian experience. In that case I recommend lighting a candle, wearing a beret and grinding the coffee right around “auto-drip,” perhaps even a little finer – just make sure to cut down the extraction time to 2 minutes or less (unless you prefer a more bitter bohemian experience.) Most people do mind the grinds in the cup (and especially in their mouth) in which case we’re talking classic French Press – an extremely coarse grind and a 4 minute immersion. No berets, but candles are still appropriate.
MORE BREWING TIPS
- Use the best quality water possible.
- For French Press, Melitta Method or any other brewing method where you heat the water manually (except Turkish), use water just shy of boiling (190 – 200 degrees). If the water has already come to a boil, let is sit about a minute before using. But if it was boiling longer than 30 seconds, you’re better off starting over with fresh water.
- For Melitta Method, infuse the grinds with enough water to make the grinds muddy and let that sit about 5 seconds (releasing the flavor), and then pour the rest slowly over the grinds.
KEEPING BREWED COFFEE WARM
- Burner plates are to be used very sparingly, if at all. If you need to keep the coffee warm for 15 minutes or less, a burner plate will do the job without too much damage to the coffee. Any longer and you should use a thermos.
- The best way to store brewed coffee is in a vacuum thermos. Tip: preheat the thermos with boiling water – this small step will keep the coffee warm considerably longer.