Heat Sealed Valve Bags
When coffee is fresh roasted it needs to de-gas. Coffee roasters commonly use heat sealed valve bags that have a one-way valve to allow the gases to escape without allowing any air or odors to get in. As long as the valve bag remains sealed it is "vacuum" packed and will remain as fresh as the day it was roasted until the heat sealed valve bag is opened. Purchasing your coffee in heat-sealed valve bags and keeping them sealed until needed is the best way to store both whole bean coffee and ground coffee for the long term.
Store Coffee in a Cool Dry Place
Once the heat sealed valve bag is opened, the proper way to store all coffee according to the coffee experts is to keep your coffee in a cool dry place. Heat, cold, moisture, oxygen and generally any kind of outside odors are all enemies of fresh coffee so caution should be taken to reduce or eliminate these. Keep in mind that fresh roasted gourmet coffee is porous so it will absorb outside influences. Whole bean coffee is a lot more dense than ground coffee so ground coffee is more susceptible to outside influences that destroy coffee freshness. Storing your coffee in a cool dry place preferably in an air tight sealed container is the best way to keep your coffee fresh for as long as possible.
Avoid Storing Coffee in a Fridge or Freezer
Many coffee drinkers are surprised to learn that freezing coffee or storing coffee in the refrigerator is actually detrimental to keeping your coffee fresh and should be avoided. Freezing coffee affects the chemical characteristics of the coffee bean or ground coffee. Storing coffee in the refrigerator is not recommended because as mentioned, coffee is very porous and will absorb other food odors that are present.
Green Bean and Roasted Whole Bean Verses Ground Coffee
The taste of coffee will vary depending on the type of coffee, the coarseness of the grind, the type of coffee brewing equipment used and of course, the age of the stored coffee.
Green Coffee Beans have the longest shelf life over roasted whole bean or ground coffee. If stored in a cool, dry place green coffee beans can last more than a year and still retain much of its flavor and aroma. The primary drawback with storing green coffee beans is that they still have to undergo a lengthier process from roasting to brewing. Very few people have their own coffee roasting equipment and green coffee beans are not as readily available on the market.
Roasted Whole Bean Coffee has a longer shelf life than ground coffee and is readily available on the market. When stored in a cool, dry place fresh roasted whole bean coffee will last for a number of weeks without losing too much flavor and aroma. It is preferable to store whole bean coffee in air sealed containers. Ceramic storage containers are recommended since plastic or metal containers can sometimes affect the flavor of the coffee over time. Glass containers are acceptable provided these are stored in cool dark cabinets. Whole bean gourmet coffee is recommended for home use for a number of reasons. As stated, whole bean coffee has a longer shelf life and provides a better, more flavorful cup of coffee, especially if brewed immediately after being ground.
Ground Coffee has the shortest shelf life of all and is best brewed right after being ground. Ground coffee is the most porous form of coffee and can loose its flavor and aroma in a matter of days. It's best to try and keep ground coffee stored for as short a time as possible prior to brewing.