wookie wrote:That sounds like solid advice. The night before if you can manage it. Four hours should be more than adequate and two hours in a pinch. Less than two hours is more likely to risk condensation. It's going to vary with the relative humidity anyway. The beans don't have to come to fully room temperature. Just enough to ward off condensation. I'd think that 50F would suffice in most cases.

I've watched Abe Carmeli take bags of coffee out of the freezer, dump the frozen beans directly into his Versalab grinder, and proceed to pull kick-ass espresso shots on his FrankenBrewtus. The man has world-class taste buds, and apparently sees no need for extensive defrosting.

I tend to defrost espresso beans before use. But non-pressurized brewing is a relatively rare occurrence in my home (maybe once a week). Rather than let my drip/vac pot coffee beans go stale, I leave them in the freezer, and weigh out what I need on a per-pot basis. I do not bother with prolonged defrosting, and it does not seem to have any impact on the cup quality. Condensation has never been an issue.

As usual, YMMV.

Marshall wrote:I actually find it nearly impossible to pull a decent shot when the coffee is gushing CO2. Not as much of a problem with pourover.

I think it's highly dependent on the coffee you're pulling. My sense is that the light-roasted SOs I get from Terroir taste better close to the roast date than the popular darker-roasted big blends. The latter seem to need a little more time to develop. But as yet I haven't worked through a broad enough sample to support that generalization.

I'm also of the opinion that coffee ages a little more quickly after being frozen, so freezing it as soon after roast as possible produces a longer period of acceptable flavor. The first couple of days after defrosting will not be optimal, but they're usually acceptable. If, on the other hand, you wait until the coffee reaches its peak after roast, then freeze, the useful period after defrosting can be a lot shorter.

I would think beans continue to age when frozen, albeit at a slower rate. That would explain both the ability to use them out of the freezer without much aging and why they exceed the use by date quickly after defrosting. Does that sound correct?

The question is whether frozen coffee is better. I think it is.

When you freeze coffee soon after roasting, CO2 stops, which means it keeps more aromatic particles (more intense). Once vacuumed and frozen, the vacuum bag does not puff (does not gain volume = no more CO2). Here vacuuming & freezing has a new purpose. Freezing is used to force the stop of CO2, instead of using it to preserve the coffee freshness (which it also does).

Cheers

mitch236 wrote:I would think beans continue to age when frozen, albeit at a slower rate. That would explain both the ability to use them out of the freezer without much aging and why they exceed the use by date quickly after defrosting. Does that sound correct?

Certainly, to the extent that the aging of coffee is an oxidative physical and chemical process, reducing the temperature will slow the rate at which it proceeds. I for one do not believe that we understand everything that is going on with coffee as it ages, nor about how freezing retards the aging process, but certainly the process is chemical and physical.

I do not believe it is established fact that coffee, once frozen and then defrosted, has a shorter "optimum" period than it would have had, had it never been frozen. We did not observe that in our studies, to the extent that we looked for it, and I have not observed that in my own usage. A few people have made anecdotal comments here to that effect, over the time since the original article was published. Anecdotal observations do not science make, although they may lead people (not me, in this case) to study the observations more closely in an experiment.

There are a lot of variables at play when one freezes coffee. How much time elapses after roasting and before freezing? What type of freezer is being used and what temperature does it keep? Does the temperature oscillate a lot (as in a frost free refrigerator-freezer) or is it relatively constant, as in a chest freezer? What kind of container was the coffee put into and how airtight is it? Etc. etc. etc. Perhaps some of the observations of coffee having a shorter optimal usage period after freezing relates to such things as how much time has elapsed after roasting but before freezing, and the use of freezers that don't maintain a constant and very cold temperature? I have no evidence to support either of these contentions, and I don't know how you could reasonably test them, either (nor do I have any interest in doing so!)

ken

Arpi wrote:When you freeze coffee soon after roasting, CO2 stops, which means it keeps more aromatic particles (more intense). Once vacuumed and frozen, the vacuum bag does not puff (does not gain volume = no more CO2). Here vacuuming & freezing has a new purpose. Freezing is used to force the stop of CO2, instead of using it to preserve the coffee freshness (which it also does).

Hogwash.
Sorry, but bad science chaps my hide. And lord knows I've chapped my own hide too often

Submit one of your frozen fresh evacuated bricks for gas chromatography after a month in the freezer and see what's in the bag. Unless you are able to extract all the CO2 out of the bean via a very limited vacuum, CO2 will out gas in the freezer.

The idea that a CO2 molecule is carrying away aroma particles is . If you run a slow moving CO2 molecule into a particle tens of thousands of times heavier, the CO2 molecule will bounce like a ping pong ball on a concrete floor.

Hi CafeIKE

I would like to be corrected if I am wrong since I am not an expert.

In my frozen packs, I see no signs of the plastic bag puffing. Do you mean that CO2 molecules are so small that go through plastic with time? Faulty sealed vacuum bags will puff. It takes a very small (microscopic) opening over time and the bag will puff, not because of CO2, but because external air gets inside (external pressure is much bigger and goes from high to low).

From the book The Coffee Cuppers' Handbook pg 9

"As it leaves, CO2 extracts other organic materials, changing them into a gaseous state at room temperature. These gasses, which are predominately esters, form the essence of coffee's fragrance."

Farther down:

"When coffee brewed is slurped, or vigorously sprayed towards the back of the palate, additional organic material, present in the brew in a liquid state, aerates and changes into a gaseous state. Also, any gaseous material previously trapped in the liquid is immediately released. These vapors, which are mostly sugar carbonyl compounds, form the essence of coffee's nose."

Cheers

Er, saying that freezing coffee stops outgassing is categorically untrue. It's just not possible, unless you're freezer is set to 0 Kelvins. If you have one of those, your coffee's freezer lifetime will be pretty much unlimited. If you can't swing a freezer that can do that, then all you can do is sharply curtail CO2 outgassing. I believe it is indeed sharply curtailed, and that's all well and good. But it isn't stopped.

I am talking in practical terms. If you leave the pack for 6 months I would imagine that something will happen as plastic is not a perfect sealant. In practice, if I use the coffee within 1 month (or possibly more) and I see nothing going on.

I use a dedicated freezer set at only 0 F, which seems to work OK for me (no puffing).

Cheers