Sunday, October 28, 2007

Storing Coffee Beans - To Vac, Or Not To Vac?

As a test, on 10/13/07 I put two AeroPress scoops each of Sumatra Decaf coffee beans that had been roasted on 10/12/07 into four pint mason jars as follows, to be tasted and compared after about 2 weeks:

A. Vacuum-sealed (with a home vacuum sealer and mason jar lid attachment), and not opened.
B. Vacuum-sealed, and opened and then vacuum-sealed again every day.
C. Closed (not vacuum-sealed), and not opened.
D. Closed, and opened every day.

I opened them all on 10/28 and did a taste comparison, using the AeroPress. My subjective opinion/results:

#1 for flavor: Coffee A.
#2 for flavor: Coffee B.
#3 for flavor: Coffee C. (Very close to B., however.)
#4 for flavor: Coffee D.

Vacuum sealing thus does seem to help retain the freshness. Probably the best thing would be to put a freshly-roasted pound of coffee beans into four mason jars, vacuum-seal the jars (and check them each day the first couple days, for they may still be degassing and undo the vacuum), and take out and grind 2 days' worth of coffee at a time to cut in half the number of times one would have to reopen and re-vacuum-seal the jar before finishing it and starting on the next jar. The resultant loss in flavor of ground coffee over 2 days versus 1 day may negate this benefit, though, and daily grinding might still be the best choice.

Also, I could take a jar to work and grind it there. Since the pint jar of beans will be used up in a few days, it won't spend two weeks being opened and closed, so it should taste better than Coffee D.

I only had 2 AeroPress scoops of coffee in each mason jar - i.e., about the equivalent of 2.5 regular 2 TBSP coffee scoops - so there was a lot of air space in the jars. I suspect that if I kept the non-vacuum-sealed coffee in a reasealable sandwich bag from which I could expel much of the air each time I opened and reclosed it, it would taste very close to the vacuum-sealed coffee. Probably the best system would be to use actual vacuum bags for the beans, and cut open and revacuum each day the one I'm using after taking out the coffee, which would pretty much eliminate all air around the beans while they're not being used. I think a good compromise between this ideal method and efficiency/cost (i.e., not having to pay for vacuum bags, and not having to vacuum reseal every day) would be to keep the beans in full vacuum-sealed mason jars with little air space, and keep the beans I'm using in a resealable sandwich bag. Since I only buy 1 lb. of coffee at a time, it will all be gone in less than 2 weeks.

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