We use coffee beans after roasting. Can we use it directly after roasting? Is there any further processes after roasting the coffee beans before being used for consumption?
Typically after roasting coffee there is a rest period during which you don't want to use the coffee.
Roughly 85-90% of carbon dioxide contained in a coffee bean after roasting will be released in the first 24 hours. You CAN immediately brew coffee with fresh roasted coffee, but the flavors will not be fully developed, and you might get a metallic taste in your brewed coffee which is a side effect of the carbon dioxide.
At my shop, we allow the coffee to rest for 12 hours before grinding for the customer, and we don't cup coffees until they have rested for a minimum 12 hours.
Additionally, there are some coffees that benefit from longer rest times. Some recommend up to 10 days rest time for espresso because you will get higher extraction yields (tds yields) after a long rest period (per Scott Rao who is an expert on the subject). Other coffees like some Ethiopians will develop more pronounced floral / berry flavors after a slightly longer rest period of around 5 days (recommended by Joe Marocco over at Cafe Imports if I recall correctly)
Other than this rest period and grinding, there is no process that needs to be accomplished after roasting coffee.
Ethiopians (and as far as I experienced Cubans) prefer to roast their beans up to darkness, then grind immediately. Ethiopians brew it more like Turkish while Cubans use moka pots. So, it is possible. (See the answer referenced below.)
However, under normal conditions modern culture prefers to degas. Degassing is discussed many times. I have the exact same answer on the issue on the site. The most cited question in Coffee SE is probably this, the question of the above referenced answer. Here is a nice blog post also cited in Coffee SE. My final word, please don't miss Nate M.'s comment here on degassing ground coffee.
- Degassing takes up to 2 to 4 days to achieve drinkable coffee. If you really want to shorten this, grind earlier. But you should try yourself for best timing.
- The best flavor is around 1 to 2 weeks. Again, you should follow your taste buds based on the beans and the roast degree.
The industry standard is around 12-24 hours of rest time after you roast your coffee. In this time, the flavors and body will start producing. Once the process finishes, you have about six days left before the quality of the roast will begin to depart and you'll have an average cup of Joe. I use a 2KG Commercial Coffee Roaster that I purchased from a local REP a while back. I noticed that I get the best cup of coffee around 20 hours roasted just past 1st crack. This, of course, is my personal opinion.
Roasting coffee transforms the chemical and physical properties of green coffee beans into roasted coffee products. The roasting process is what produces the characteristic flavor of coffee by causing the green coffee beans to change in taste. Unroasted beans contain similar if not higher levels of acids, protein, sugars, and caffeine as those that have been roasted, but lack the taste of roasted coffee beans due to the Maillard and other chemical reactions that occur during roasting.