I ran another non-rigorous experiment. Again, I wished I had the skill to cup coffee. I had shared a link to an article about “to freeze or not to freeze” coffee beans before. Bea likes to freeze many food items, usually because she can’t eat everything she buys, receives, harvests or makes. There are many legitimate reasons for wanting to freeze foods in order to keep them as fresh as possible. Many items freeze and thaw fine, but some ingredients just don’t come out the same.
Back in early April, I let a half pound of coffee sit & de-gas in its valve bag for four days after roasting, then I double-bagged that bag in ziploc bags and put it in the freezer. My plan was to later defrost it and taste it against a freshly roasted batch of coffee.
A couple of weeks ago, I took that frozen bag out and defrosted it in our cupboard, minus the two ziplocs, but still in the original packaging. I gave it two days. Then I gave my husband a blind tasting of that previously frozen coffee against coffee that was roasted five days prior. The “fresh” coffee hadn’t been immediately packaged in a valve bag, but was just stored in a ziploc bag. For each cup, I weighed the coffee, ground it the same, used the same temperature water (thanks to our OXO Brew pour-over kettle), and used the same type of cups. The last one brewed was hotter, so I probably should’ve controlled for that. But we did also taste when both were cooled.
Both of us felt the (what was revealed to be) “frozen” coffee tasted a bit more fruity or acidic, and the “fresh” coffee had more chocolate favors. Both coffees were still flavorful. This tasting reminded us of how challenging cupping was. You can taste they’re different, but how do you describe it? Back and forth we sipped, concentrating.
In hindsight, I should’ve kept a bag of coffee from the same time and NOT frozen it, as a third tasting.
Layperson’s conclusion/tips: if you want/need to save coffee by freezing it, it doesn’t seem to suffer. Do your best to control moisture when freezing and thawing, e.g., vacuum packing or double-bagging in ziplocs. Thaw the beans before you grind them; they’ll be more flavorful. In my college days, I used to store my beans in the freezer, and I ground beans straight out of the freezer. If you want the best flavor you can still get, don’t do that.
FYI, we did another experiment precipitated by purchasing coffee a week before a weeks-long vacation. We double-bagged and froze half of the remaining coffee before we left. After vacation, I made pour-overs of the thawed previously-frozen coffee and compared it to the coffee in the jar in the cupboard. We have two drippers now, so I could brew them in parallel. I served them as a blind tasting to my husband. The frozen coffee had retained much more flavor.
Fun. Unscientific, for sure, but fun. Thanks for posting your experiment.
Another test would have been frozen beans but not thawed and taste if any impact. Thaw might start introducing moisture?
Thanks for the experiment results!