Coffee can be purchased from several sources, grocery stores, cafes where cafe roasting takes place or mail-order. When buying coffee at the cafe, you want to look for the coffee bins that hold the fresh roasted coffee, usually the same day or maybe 1-2 days old at most. What to look for: Ensure no moisture, or excessive oils coat the container.

A way to tell that the bins have not been cleaned or the bin is sealed too tight. Once the coffee is roasted there is still a stage in the roasting that is taking place called de-gassing. The coffee beans begin to emit Co2. Will Co2 effect the taste of the coffee? We'll take on that subject later. But for now let's just say we want the roasting process to be complete and degassing is part of that process. How long to degas?

I have read from 12-48 hours is the time you want to wait before brewing your coffee. The important thing is to be aware of this process. Mail order is another way to get your coffee. In this case you want to get coffee that is bagged in a package that contains special ONE-WAY degassing valve.

This serves two purposes.

• The roaster can bag the coffee a few hours after letting the beans cool down and preserve the fresh roasted coffee right away. By bagging right away, we can prepare the coffee for same day shipping and use the time it takes to mail the coffee to continue in the degassing process.
  
  


• The other benefit is that the air which contains Oxygen and Nitrogen will mix with the Co2 gas and together becomes evenly diffused. Once the pressure inside the bag is greater than the outside, the degassing valve will allow the combined Oxygen, Nitrogen, and Co2 to escape. What is beneficial in this process is the following. Because the gases are mixed together, Oxygen is also part of the gas that escapes though the one-way valve. Resulting in a reduction of Oxygen (approximately 40%). Which is a great benefit.
  
  

Note once coffee is roasted the optimum coffee drinking experience is limited to 2-3 weeks. But this packaging (bagging) process helps slow down the degradation of the roasted coffee until you open the bag.

fatboy