I. On Using a Burr Grinder for Coffee, and Why: Thanks to Bob H who first told me why burr grinders are better than blade grinders, for making quality coffee. I researched this extensively, and carefully chose a burr grinder, and have just completed a taste/smell test comparing blade grinder to burr grinder (thanks to Jane for suggesting I do that before investing in a second burr grinder for our farmhouse).
Here's what you need to know, for any coffeemaking method which requires you to grind coffee beans (that includes, at least espresso and French Press (press pot) and drip-through-filter methods).
1. First, keep your coffee beans whole (unground), in a sealed container. I bought a glass jar with a glass lid that has a rubber seal and clamp lock, cheap at Target. If you leave your beans lying in an opened sack, they will lose their volatile oils and you will lose flavor and aromatics. I believe there is no need to freeze them, though--just seal them somehow and keep them in the dark.
2. Second, don't grind your beans until you are ready (I mean, really ready) to make coffee (I use French press, so this means I boil the water first and only then grind the coffee). The goal is to minimize the time between grinding and drinking. The reason for this step is the same as in point 1: To keep your coffee fresh and to maximize the aromatics and taste. Grind size for espresso machines is finer, and grind size for French Press is coarser. Every palate is different, but I use 2 tablespoons of whole beans per 12 oz cup of coffee, and I steep for 2.5 minutes only (I'm a Supertaster, and bitter flavors absolutely kill me--I can't eat dark chocolate, Stevia and artificial sugars all taste bitter to me, and if you really want to make me angry, tie me a chair and pour tonic water into my mouth).
3. About grinders:
a. A blade grinder (which we used until recently) is cheap (about $15) and it does grind up the beans, but it makes every size particle from "dust to boulders." This prevents consistent flavor extraction: The dust over-extracts and you get bitter flavors, and the boulders don't divulge as much flavor, so you get a strange concoction of too-bitter and inadequately-extracted coffee.Also, the rapid action of the spinning blade can heat up the coffee grounds, robbing them of their aromatics and flavor too soon.
b. A conical burr grinder has two counter-rotating cone-shaped grinding wheels (made of either ceramic or steel), which grind the beans into more-consistent size pieces. A good burr grinder operates quickly (only takes a few seconds to grind beans for a cup of coffee) and, paradoxically at the same time, slowly (the grinding action happens slowly--the gears turn rather slowly--and this prevent the beans from heating up, which can release aromatics and flavors prematurely). A good burr grinder also lets you select the grind size you want. (I think the grinder controls the grind size by changing the distance between the two burr grinder wheels.) Beware! Some so-called "burr grinders" are nothing of the sort when you take them apart--you need to thoroughly research the grinder you want, and read carefully what coffee experts say about each grinder. I chose the Capresso Infinity # 560.01 (about $75 on Amazon now); the new model is the 560.04 and it's about $100. Most sub-$100 burr grinders have very negative reviews, so if you go this way, don't skimp or you will be wasting money. I chose the model I did because it is classed with the other good $100+ grinders, but due to its being end-of-life (in terms of a product's natural life cycle), it's cheaper now.
My grinder has stainless steel grinding wheels, and an easy setting from coarse-to-fine (you merely rotate the upper coffee bean holding chamber, to select grind size), and a timer switch for grinding on-off (once you hear that all the beans have been ground, you advance the timer to "zero" and it shuts off).
And you will need a brush to keep the burr grinder wheels clean. Here's the grinder on Amazon (the price has gone back up, it appears--it's $93 for Amazon Prime now):
4. The Test: So I made 6 oz of coffee, using the same beans, same quantity of beans, and same water and press time, with both our blade grinder and the above burr grinder (using two identical French Presses). I used, and like, Luckman Coffee's "Chiapas Altura" Mexican coffee (they're in Woodland). It's a lighter roast (so it's less bitter), and has a hint of chocolate and great coffee flavor.
It was no contest at all: The burr-ground coffee was much darker. It had much more aromatics. In the mouth, it was much richer than the blade-ground coffee; it had more body and made the blade-ground coffee taste thin by comparison. Wow-what a difference! I'm a believer. If you need a holiday gift idea for a friend who loves coffee but is using a blade grinder, the Capresso burr grinder might be a great idea.