Rest
Rest is very important. Especially in the case of freshly roasted coffee beans. Grinding and drinking straightaway after a roast is a no-no and a waste of beans. Pulling a shot at this time will most likely give you so much crema you will taste the baking soda effect. Plus, it might taste lemony. This crema also will not last as long as the crema made from well rested beans. It tends to clear out in just a minute. The beans need at least 3 days of rest in an almost vacuum container with a one-way valve to let the carbon dioxide escape. Here is a discussion of why coffee needs to rest on home-barista.com.
And on the 3rd/4th day, when you finally unzip the zip-lock bag, you will be well-rewarded with the fragrance of the fresh roast. And if the espresso you pull smells and tastes the same as this fragrance, all that work and rest and money invested in equipment just might be worth it.
:)
Something to point out.. Putting in a one-way valve helps the roasted beans stay fresh in 3 ways.
1) Sunlight 2) Moisture 3)Oxygen.
First 2 is obvious, as the bag provides this barrier. For oxygen, it is the release of the carbon dixoide that drives/dilutes the oxygen out of the bag.
Alas coffee by its complex nature never makes it for us.. some beans do require resting more days for the flavour to develop and evolve..
Ladies and Gents, previous comment was left by CGSG leader, Kai Seng, who brought the Singapore chapter of Coffegeeks together.
Some points to add:
Roasted and unroasted coffee should be kept in darkness. Vacuum bags with one-way valves are good for roasted coffee, and cotton drawstring bags for green beans. The humidity in Singapore is fine for green beans. It helps in the aging.
I have a patented (I wish!) version of the one way valve bag. It’s a one way valve JAR!
I buy a suitably sized mason jar, peel off the plastic valve from a donor coffee bag, drill a tiny hole in the lid of the jar and then glue the valve to the inside of the lid. Perfect! I then dump my freshly roasted and cooled beans into the jar and place in a dark, ventilated cupboard for two days.
Finally, I transfer my degassed beans into a plastic coffee storage jar (one of those with the wine-pump oxygen extractor).