Everything coffee lovers associate with a freshly brewed cup of joe, such as its flavour and aroma, comes from the roasting process.
When a raw, green coffee bean is picked, it contains the precursors to, but doesn’t yet exude, those complex flavour profiles that give coffee its quintessential smell and taste.
It’s the roasting process that imparts a flavour explosion of chocolates, caramels, flowers, and fruits.
Once a green coffee bean is exposed to the extreme heat of a roaster, a green bean’s complex makeup of minerals, carbohydrates, amino acids, proteins, lipids, water, and caffeine meld together in chemical reactions that give way to that nutty and irresistible smell and taste of coffee.
Unfortunately, like most products of living organisms, coffee beans are highly susceptible to ageing. The moment a roasted coffee bean is exposed to air, it immediately begins to degrade and lose its tasty flavour. This is why many roasters — but not necessarily all — suggest that you brew your coffee beans as soon as possible after roasting so that you can get the freshest, most delicious drink.
But how do you know how if your store-bought beans were recently roasted? Here are four ways to find out.
When your beans aren't pre-packaged -- maybe you bought them in bulk -- pop a half-cup of beans into a resealable plastic bag, press out the air, and let them sit on the kitchen counter over night.
If they have been freshly roasted within the past seven to 10 days, the bag will puff up from an outgassing of carbon dioxide.
(image url='http://static.techinsider.io/image/562025939dd7cc14008c2627-1912-799/coffee%20outgasing.jpg' alt='Coffee outgasing' link='lightbox' size='primary' align='center' nocrop='false' clear='true')
If they're not so fresh, the bag will remain flat. And you will be sad.
(image url='http://static.techinsider.io/image/56202678bd86ef18008c2438-1914-780/stale%20coffee%20in%20bag.jpg' alt='Stale coffee in bag' link='lightbox' size='primary' align='center' nocrop='false' clear='true')
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