part two
This is part two in a series of posts where I will recount my experiences as I explore my backlog of frozen coffee. Read Part one here.
After several weeks, I’ve made a noticeable dent in my icey backlog. There’s space in the freezer and thoughts in my head, so let’s dive into my experience brewing coffee that’s been frozen for nearly a year.
g-g-g-g-grinding f-f-frozen?
The first question you should ask yourself when brewing something from the freezer is, “Am I grinding thawed or frozen?”
I used to be in the thawed camp because it felt familiar. I could use the same dial in and I didn’t mind planning ahead, leaving the coffee out overnight.
But now I’m totally in camp grind frozen. And there are a few reasons why.
grinding frozen improves particle distribution (or so I’m told)
When you grind frozen, the general consensus seems to be that you get a tighter particle distribution. Essentially upgrading your grinder for free. I have no way to test this but every brew with frozen coffee went well and I never tasted any thing negative that would point to the grinder being an issue.
it’s convenient
You don’t have to plan ahead, just reach into your home cafe and brew. That instant variety is part of the fun of freezing after all.
thawing introduces new variables
When you thaw coffee you’re changing it, and exposing it to the elements. Ideally it’s still in the same airtight container you froze it in, but thawing still introduces variables (like moisture, light, temperature, and time) that could degrade the flavor you carefully sealed away.
So with all that in mind, I stuck mostly to grinding frozen.
You might need to grind a little bit coarser than you did before freezing; people report that grinding frozen shifts the peak distribution finer. For the Pulsar I mostly stuck around the same grind size but your mileage may vary.
where to put those extra beans
This part will focus on the centrifuge tubes I used, you can read more about the process here. Those tubes hold around 20 to 23 grams of coffee and work great. The problem is that I brew with 15 grams.
I appreciate the extra beans for things like purging my grinder, but when I have a few 23 gram tubes, eventually there’s enough left for a full dose. Here, the question is, do I let the extra dose thaw and sit for a few days or do I return it to the freezer?
I don’t have a rigorous scientific test for this but I say, put that guy back in the freezer.
Again, thawing introduces new variables. It seems fine to thaw a coffee and then brew it right away but the combination of thawing, oxidation, and extended aging time degrades the flavor.
I enjoyed the leftover doses much more when I put them right back into the freezer.
the good, the bad, and the just okay
Now onto the fun part, what did I brew?
One of the first coffees I brewed was Sey’s Bitalina Lopez from Honduras.
Frozen 16 days off roast, in centrifuge tubes, for 335 days
I’m pleased to say that it tasted wonderful. I even enjoyed it more than I remembered liking it in the first place. It was syrupy with notes of pomegranate, cherry, and a raspberry acidity as it cooled. There was nothing I noticed that would point to quality degradation from freezing.
And it’s a similar story with Sey’s Hamasho extended fermentation from Ethiopia.
Frozen 15 days off roast, in tubes, for 333 days
I really enjoyed this coffee when I first had it, almost a year ago, and like the Lopez, it tasted delightful. I brewed both using the Pulsar, and the cups were as good as I remembered. Tons of peach, and pleasant florals. I’m also using softer water now and I think that helped these coffees shine.
Now onto the just okay.
The two Tim Wendelboe Kenyan’s I froze, Karogoto and Kagumoini were good but not great.
I froze these for less time, 218 and 214 days respectively, but I froze them further off roast. 22 and about 30 days. I think for Tim Wendelboe, I would freeze earlier next time.
For lighter roasts this would probably be fine but you also have to consider how long you think it’s going to be frozen. If you’re not touching it for a year, I don’t think I would wait until “peak” flavor to freeze, because that coffee will continue to very slowly age.
Although, I’ve never frozen an ultra-light coffee, that could be an interesting experiment.
Now onto the not so good.
I froze two coffees from Passenger, Hermenegildo Marin from Mexico and Marilyn Laucata from Peru. And unfortunately these were disappointing.
Both stored in tubes, frozen 16 days off, for 346 days
Both had a really noticeable roastyness and lack of flavor that made them hard to enjoy. The Marin still had a nice dry aroma but each brew disappointed.
So what changed? These followed the same freezing protocol as the other coffees. Well, maybe I froze them too late or for too long, but I have to assume that what changed is me, and my taste preference.
But I will save exploring that thought for part three…
