Science Says: “Don’t freeze your coffee”

Serious Eats is your favourite food blog. You just may not know it yet. They conducted a blind taste test (with the help of my food hero J. Kenji Lopez-Alt.

20101014-coffeetastetest.jpg

The table was littered with tiny paper cups numbered one through eight, each representing a different method for storing coffee beans:

  • 1. Whole beans stored at room temperature in a Ziploc bag (Ziploc bags are not hermetically sealed—air can still escape and enter the bag)
  • 2. Whole beans stored at room temperature in a one-way valve bag (from which CO2 can escape but stale-making air can’t get in)
  • 3 and 4. The same beans stored in the freezer
  • 4, 5, 6, and 7. Ground coffee stored in the same 4 manners

The grinds and whole beans all came from the same batch. The coffee was stored for two weeks before we cracked it out, to get the full effect.

The taste test followed an earlier, less scientific, test, which came up with the following conclusion (which I agree entirely with)…

“Looking at the results with an open and caffeinated mind, my recommendation is to treat fresh-roasted coffee just as you would fresh-baked bread: Better to buy a little bit, use it up while it’s fresh, and buy more when needed. And, just as with fresh-baked bread, the second-best—though by a mile—option is to prepare it into individual servings and store them air-tight in the freezer (in the case of bread, that means slices; for coffee, that means premeasured doses you’d use to make a certain size batch of joe at a time), using only what you need at any time and never letting them thaw and refreeze.”

When beans thaw they sweat and their chemical make-up changes. It’s bad. Mmmkay.