Why a coffee grinder is essential has many reasons. First, roasted coffee beans start to lose their aroma immediately when exposed to the air and usually have a dull unpleasant taste within five to seven days. This process of oxidation happens even faster with ground beans. They will start to become dull and unpleasant after 24 hours.
Roasted beans can be put in the freezer to help maintain the freshness of newly roasted beans. However, after five to seven days the freshness of the coffee will begin to decline even in the freezer. Putting ground beans in the freezer is not recommended. If you choose to put a small batch in a sealed glass or ceramic container, once you take them out of the freezer and use part of them you cannot put them back in the freezer. The main reason is they have now been exposed to air, moisture, heat and light.
A coffee grinder is a must if you want the freshest tasting coffee possible. Whether you buy green coffee beans and roast a small amount at a time or whole coffee beans that are in a dark sealed bag, a grinder will allow you to grind the size of beans who want. Household coffee grinders have at least four or more grind settings. If you want a grind for a drip coffee maker or a percolator, you can grind the exact amount you need just before you make your coffee. You will be surprised in the improved taste your coffee now has over pre-ground coffee that comes in a bag.
If you are an espresso fan, you will notice the difference when you use an espresso grinder as well. Grinding your coffee just before you make an espresso improves the favor of your espresso. If your best coffee grinder has a greater number of grind choices or an infinite number of choices, you will notice that different espresso grinds will change the aroma and flavor quality of your espresso. This ability to have different espresso grinds also allows you to personalize your espresso strength. Finer grinds of coffee beans produce a stronger flavor espresso. Pre-ground espresso coffee beans are what you get without any real choice in grind