We recently conducted an experiment testing the efficiency of valve equipped bags in preserving the freshness of Vita’s beans. The challenger : the valve-less compostable brown bag.
First, a small batch of Vita’s trademark espresso blend, Caffé Del Sol, was roasted and then allowed to cool. It should be noted that freshly roasted coffee releases a tremendous amount of carbon dioxide, quite rapidly during the first 24 hours, and then at a slower pace over the next few days. This is why espresso performs best 3 – 6 days after the roast ; the carbon dioxide has been released, and does not find its way into your doppio. Harsh tasting, bubbly shots are a sign that your beans need to rest longer.
After cooling, some of the beans were sealed in the valve bag, and some in the compostable bag. We hid them in a cool dark place and waited…
Three days later, the beans had exhaled most of their CO2, and were ready for testing. One after the other, we poured beans into the hopper, and dialed in our shots. There was no noticeable difference between the two. Pungent dark chocolate and praline aromas, thick luscious amber crema, and a long caramel finish. Mmmm.
So we resealed the bags and waited some more. . .
Six days after roast, the beans that were stored in the valve bag performed much like they had on day three, producing excellent shots with the vibrancy and intensity we expect from Caffe Del Sol. The beans that were stored in the compostable bag, however, had begun to lose their luster. The aroma was weaker, and the shots tasted a touch flat.
By day nine, the difference between the two was obvious. The beans in the compostable bag had become noticably stale, the complex chorus of aromas reduced to one timid note; the syrupy amber bass reduced to a thin tenor. The valve sealed beans continued to perform well, producing a symphony of sweet caramel toned crema.
While the compostable bags do allow the beans to release CO2, (a good thing), they also allow the agent of staling, oxygen, to come in contact with the beans (not good). The valve sealed bags keep the oxygen out, while allowing the carbon dioxide to escape. Provided you keep this bag in a dark, cool place, you are doing the best possible in preserving the freshness of your beans.
Until something better comes along, we at Caffé Vita will continue to package our beans, for both wholesale and retail, in sealable bags equipped with a one-way valve.