Rise and Grind

If you can change one small thing about your coffee drinking to make it better it would be one thing: get a grinder.

Why we Grind Coffee?

The basic goal of making coffee is to get what’s sealed inside the bean (namely, the delicious flavor components and oils) out of the bean. The original method involved boiling the whole roasted beans in hot water while agitating them. With some patience and lots of time you’d eventually end up with a bitter, high-caffeine, coffee solution.

Luckily for us our coffee forefathers eventually came up with a more efficient method to extract the goodies from the coffee! By grinding the coffee beans you help the water to extract efficiently the solubles that are responsible for the taste and aroma in coffee.

Let me explain the logic behind this.

The Efficient Extraction of Solubles

If you take a whole bean and cut it in half you’ll increase the total surface area of the bean. As a result the extraction efficiency is greatly increased. Why? Because there’s more surface area for the hot water to act upon and from which to extract the flavor components.

Now take these two halves and cut them into halves again. Guess what, you’ve just further increased the overall surface area and thereby helped along the extraction efficiency even more. Eventually you’ll end up with just the right grind size for your preferred brewing method.

The benefit of all this “cutting” is that the extraction efficiency dramatically cuts down on the brewing time. But that’s not the only reason why we grind coffee.

Smaller grind particles make for a more complete extraction

The smaller particle size makes the distance from its center shorter. This allows not only for a more efficient extraction, but also for a more complete extraction of soluble flavors contained within the particle.

Why You Should Not Buy Pre-Ground Coffee

A roasted whole coffee bean is a beautiful, protective package that keeps the coffee oils exactly where we want them, namely, inside the bean. As long as you don’t mess with the beans the flavor components, which are very delicate, volatile and water-soluble substances, will be safe. However, break the protective shell and all bets are off.

So, let’s take a look at four reasons why you, as a self-respecting coffee lover, should not buy pre-ground coffee.

1) Contamination

Coffee oils are very delicate, which makes them an easy victim of contamination. Whatever odors are around ground coffee will taint it in ways that will not contribute to your coffee tasting experience.

2) Oxygen

The cells inside the roasted coffee bean contain approximately 1,000 different volatile aromas and flavors. Once ground the volatile aromas are immediately released and they react with oxygen in the air (oxidation). After 15 minutes ground coffee loses about 60% of its aroma.

3) Moisture

Coffee oils are water-soluble. That’s a good thing or we’d have a very had time trying to get the oils out of the bean. This fact however poses a great problem for ground coffee. When ground coffee is exposed to moisture in the environment it immediately starts to dilute the oils.

4) Carbon Dioxide Depletion

Increased surface area permits for greater carbon dioxide (CO₂) gas liberation. During the roasting process a lot of CO₂ is created. Since the bean is porous, some of it is lost during the cooling process. Much of it, however, is retained within the cells of the coffee bean. This CO₂ plays an important role in that it is the main method for getting the essential coffee oils into the coffee once they are released.

The Problem is that the increased surface area created after grinding permits for greater CO₂ gas liberation. In fact within 60 seconds of grinding 80% of this gas is released into the air. Wait too long after grinding the coffee and you’ll trade your Ferrari for a go cart with under-inflated tires.

The Solution: always grind your coffee freshly just before brewing. Follow this rule and you’re one step closer to paradise in a cup.