another_jim wrote:Maybe Abe isn't worried, but I stick by advice to not unseal frozen beans until they hit room temperature.

I admit this is based merely on logic, rather than direct experiment. from How to defrost frozen coffee beans

Time for 'speriment

3 125g identical jars of frozen familiar espresso coffee from the same batch.
Bottom marked to be identifiable later, but not identifiable when viewed normally.
Remove 1 jar several hours ahead of the other 2 to allow to come to room temperature.

Open 1 of the frozen jars and remove 1 shot worth of beans. Repeat 2x @ ~20 minute intervals. [discarded]
Remove 1 shot from the previously defrosted jar. Repeat 2x @ 20 minute intervals. [brewed]
Set aside all 3 jars for 3 days.

Remove 3 shots from the previously unopened jar to equalize volume.
Enlist assistant to mix up the jars.

Sniff test each of the jars.
The missus : "These two smell like coffee. This one smells like WD-40."

I had the missus single dose charge the grinder from the 3 jars [we used a ½ shot purge] so I didn't know what coffee I was brewing. [Brew ratio did not vary significantly, ~150%]

Two shots lacked sweetness and had a musty nut after taste that lingered in the middle back of the tongue.
Turns out these 2 shots, of 6 tasted, were from the jar opened while frozen.

Thanks for doing this, Ian.

This is interesting but it seems a bit too extreme to be believable, at least to me. I'd expect much subtler differences, from my understanding of what is going on physically with the coffee, tempered by the limitations of human blind tasting.

If several other people repeated it and had the same results, or if it was done with larger samples and more tasters, I'd be more inclined to believe it as representing something real.

Once again, I have no personal experience with using coffee straight from the freezer, or coffee that has had obvious condensation on it while defrosting.

ken

Cupla things I forgot to mention :

• the coffee is moderately dark : overall sheen, some visible droplets
• it was raining when I opened the frozen jar, so humidity was high : 93% on local college weather log

another_jim wrote:Abe drops his beans directly from the freezer into the grinder. This is best case handling, since the grinding heats the beans before much condensate can form.

Indeed so. As to my experience with that method, I've been doing it for almost three years for both drip and espresso. I would notice the funk if it were there. But regardless, I think that this deserves a well structured experiment for the mere reason that the process of defrosting the beans properly (in their sealed container) can be time consuming in its prep if you enjoy a variety of coffees at a time.

There are on average eight to ten different coffees in my freezer at any given time. Dividing 8-10lbs of coffee into small batches of say 60 grams in small mason jars will require 56-70 jars. That is just not practical.

Abe Carmeli wrote:Dividing 8-10lbs of coffee into small batches of say 60 grams in small mason jars will require 56-70 jars. That is just not practical.

It could be cumbersome, so 60 jars is probably not a good solution for a lot of people. But it seemed like a good idea at the time (at least to me). So I followed this three step program:

1. Identify friend, acquaintance or co-worker with infants & ask them to save their empty baby food jars
2. Collect 100 or so empty jars and run them through the dishwasher
3. Fill with coffee beans and freeze

Because the jars are very small, I can fit 50 - 100 jars in two shallow, open top cardboard boxes in my freezer. This has been a very workable and convenient solution for me.
.

Abe is obviously single dose grinding, so his strategy can work fine for that. If on the other hand you don't single dose grind, it wouldn't be practical.

I have another "solution" to having several coffees available all the time, which is to have several grinders. Of course this is cost prohibitive and takes up space, so most people would choose not to do it. With my 4 grinders I typically have most or occasionally all of them with coffee in the hoppers, giving me a choice typically of around 3 coffees, usually all SOs. With this approach I am able to freeze in jars holding about 150 to 275g each (I have different sizes). Since I freeze immediately after roasting I don't mind having the coffee slowly come back to room temperature and usually let it sit in the jar for a couple of days to let it "mature" a little.

ken

I'm missing something here.
1. How does Abe get a single dose out of a frozen batch w/out exposing the rest to moist air?
2. Is this a practical experiment (in which case it seems like a lot of effort) or is there a larger principle or mode of practice to be informed? How long does it take 125g, 270g, or 1kg of frozen to thaw to room temp? And if that's too long, would popping the jar into some warm water help?

I vac seal and freeze immediately. Smaller portions are less cost effective, but add flexibility. Interesting to watch the frozen-brick bags loosen and puff out during degas.

Martin wrote:1. How does Abe get a single dose out of a frozen batch w/out exposing the rest to moist air?

I freeze in large mason jars and open the jar for each shot. A jar may be in the fridge for three months during which time it probably would be opened ten times. It is exposed to air very briefly when it is opened.

The experiment should test the following two questions:

1) Is there a difference between coffee frozen in a large jar which is opened multiple times, and coffee frozen in a small jar which is opened only once to empty its content and grind over a period of say 3 months. Does it affect the taste of frozen coffee? This should be tested against coffee frozen in small jars that were opened only once. Again, the coffee here is ground while the beans are still frozen and immediately.

2) Is there a difference between coffee that was frozen and properly thawed - in its sealed small jar, and coffee that was ground frozen, being stored under the same conditions. This experiment tests whether beans need to be thawed at all after freezing.

The practical implications to this experiment are big. If there is no difference in taste, beans can be frozen stored in large jars, and can be ground frozen. Time saved probably years in aggregate. Price: well, that's a time consuming experiment, and the only way to do it over 3 months is to do it as a community. In other words, volunteers from this forums will experiment separately, at home, following the same protocol. We will publish the results.