Please refer to the pictures above. The coffee on the left is about 48 hours old. This coffee is really fresh. The flavors and aromas that make that coffee really good are still intact. The coffee on the right is about 2 months old. Visually it is very oily and the beans are sticky in feel. If you buy whole bean coffee from the store and it is covered in oil, don't walk run. It is not fresh. That oil on the surface goes rancid pretty fast and creates a sour, funky smell. Personally, it reminds me of diesel. I don't know about you, but I don't like petroleum in my cup of coffee. Believe it or not, majority of the coffee that is on the shelves at your local grocery store is a lot older than 2 months. In reality, 2 months is pretty young for store bought coffee. I would like to make a disclaimer though, decaf coffee ages faster due to the de-caffeination process. The cellular structure is broken down during the process, so the oils essentially rise to the surface much faster. I recommend looking for the roast date even closer when buying decaf.
Can I give you another piece of advice? IGNORE EXPIRATION DATES, LOOK FOR ROAST DATES. Most coffee companies don't put their roast date on their packaging. Did you know that 90% of the coffee sold in your local grocery store is stale?? Most manufacturers set the expiration date on their coffee packaging 9-12 months after roast date. So if you pick a bag of coffee and it has an expiration date of 01/11, there is a good chance it was roasted 04/10 or early as 01/10. That coffee is dead as a door knob as my mother would say. NEVER BUY COFFEE FROM THE FINAL MARKDOWN AISLE. It is absolutely dead. I don't care if it is a nickel for 5lbs, keep your hard earned nickel and apply it to a bag of fresh roasted coffee. Buy fresh roasted coffee, your nose and your tongue can tell the difference. Stay tuned, you are on your way to the perfect cup. Be blessed.