I think the point is - if RDT is not a bad thing, then why would a small undetectable amount of condensation be a bad thing?

As to whether grinding frozen is "better"' I think the first step is to confirm is there even a physical difference between particle size/distribution from beans ground at room temperature vs beans ground frozen. Someone with a fancy microscope can probably figure this out, but perhaps an easy way is just to observe if there is any difference in flow rate between the two. I.e. Does going from frozen to room temp require tweaking of the grind to hit the same output and time. If YES, then clearly something must be "different" with respect to particle size and distribution I would think. From there, taste testing can help you to decide if that difference is better or worse.

In my case, I find my grind does need to be tweaked, and I seem to prefer the frozen beans but I've never done a blind taste test to confirm. Would love to see more testing on this subject because it's something so simple and easy to change, if there are benefits to be had.

JohnB. wrote:You are comparing the condensation on a steel pitcher to what you'd see on a roasted coffee bean??
As far as whether frozen beans taste better or not I just passed on my own personal experiences.

Why, yes. Yes I am. Why would one material be different than another regarding accumulation of condensation?

If I am scientifically proven wrong about that, I will most appreciate acquiring that insight/knowledge. It's about true facts and I have gratefully been proven wrong from time to time on something I think is factual.

Truth has no ego and no agenda.

Very interesting.

And anyone who has ever split frozen logs knows they are easier to split than non-frozen logs, for what that's worth relative to this study.

I was sitting here puzzling that perhaps the surface temp of the coffee bean will rise very quickly past the dew point but was not coming up with an explanation as to why. The insulating properties of cellulose would explain that.

Edit: A rapid rise in surface bean temp is something I can measure and see the rate of rise of the readings to, at least, get some kind of data. I have a laser Pyrometer PCE-777 I use to check surface temps when smoking meat in the smoker. (you probably can guess I have been measuring all over the E61 group head with it to locate and measure the hot spots and see the cooling effects of HX machine flushing at various points simply out of curiosity)

Charlene wrote:Typically, there is approximately 15% moisture content (give or take) in roasted beans from what I have read, all things being equal.

I think you've read some poor information then. Unroasted coffee beans don't generally have that high of a moisture content (they'd be more prone to spoilage). Most green coffee is brought down to around 11% before export for that exact reason.

Roasted coffee usually has moisture content around 3% give or take.

Thanks, Tom. I highly regard your acquired knowledge and will take that under advisement.

BTW, I noticed that Sweet Maria started giving thought to protecting green beans in ziplock bags at some point in the past.

Edit: Thoughts on this?

Water content of roasted coffee: impact on grinding behaviour, extraction, and aroma retention
http://link.springer.com/article/10.100 ... 008-0852-8

Charlene wrote:It seems this study was geared at lowering cost for mass production of commodity grinds by the coffee industry.

Chris is deeply involved (and respected) in the specialty coffee industry and well worth following on Twitter: @chhendon.

FWIW, the alt.coffee regulars did home tests of freezing coffee (mainly in home deep freezers) years ago and found they preserved flavor for many months. George Howell keeps his best greens frozen for the same reason.

Delighted to make your acquaintance, Marshall. It's always helpful to gain perspective of reputation of individuals providing information. I will check out his Twitter timeline. Thanks. I admit to some skepticism as the segue-way was via a newspaper article written by a reporter based on an apparent conversation.

Had not given much thought to freezing green beans, previously though I have read anecdotal information on it several years ago.

Edit: I like his sense of humor

"Christopher H Hendon ‏@chhendon 21 Nov 2016

Excited state calculations are not nearly as exciting as they sound."

The approach the Bath/MIT researchers are using is scientific. My anecdotal observations, while satisfying my notion of myself as a coffee expert as I post them, are likely of limited value to you. The Times article was well written, and well researched, but I suspect not by an experienced coffee person. The reason? Author Joanna Klein states, "An inconsistent grind means sour taste from the small grains, and a bitter one from the big, all at the same time." I think she got that backwards. Still, good overall job on the article for someone with an apparently casual personal interest in the subject.

Note that the temperature of a typical home fridge, let's say -6.7°C (20°F), while the temperature of liquid nitrogen is −210 °C (−346 °F). So, if we take room temperature as 20°C (68°F), the differrence between the freezer's temperature and room temperature is 26.7°C, or about 13% of the difference between liquid nitrogen and room temperature.

Given the possible condensation issue, would it be worth it to store coffee in the freezer? Would the gain offset the liability? How much does such a relatively small cooling of the coffee drupes (beans) actually affect grindings? Also, what the heck grinder are we using? Many times the choice of grinder may have a more profound effect on ultimate coffee flavor than a 13% temperature reduction. If you are using a blade grinder, this conversation is mere academic poofery as you will simply never get even particle size, ergo even extraction, ergo delicious coffee using one of those.

I certainly don't have definitive observations about the efficacy of home freezer storage as it relates to grinding, but I'll be very interested in reading a fuller account of the Bath/MIT research when it's released at WBC in July.

Currently there is a lot of hot (air?) debate on this subject. The argument against storage in the freezer centers around two disadvantages, namely moisture and temperature fluxuations. Moisture is mostly a problem if the coffee is not stored in an airtight, and preferably snug-fitting container. So vacuum sealed coffee in the freezer for longer-term storage, ignoring for the moment the grinding question, seems like it's not a bad way to extend the life of the coffee. I'm swimming in coffee at present, my SO having arrived from Brazil loaded with samples from Santo Gråo and Coffee Lab (Sao Paulo), so maybe I'll vacuum pack some of these for later sampling as I can only drink so much coffee in a day.

In Shanghai, a tea merchant said, "I will prepare your tea," and went to the freezer where he removed a pre-measured amount of tea in a tiny bag from a larger bag containing many similar pre-measured packets. Perhaps this approach might work for coffee, also?

In summary, I think we need more and more specific information. Then we'll need to consider the pragmatic logistics of how to implement methods implied by the research. All of this, of course, means possibly changing our customary habits, and, if there's one thing you can be sure of, some will resist and some will embrace any such changes.

Cheers, James R.

Hi James,

The topic focus is about a study done to ascertain whether grinding frozen beans will gain an improvement in the size homogeneity of grinds, although freezing beans simply to preserve flavor was brought up as an aside.

The temp of my freezer is maintained at -2 F, -19 C with the refrigerator section maintained at 36 degrees F, 2 degrees C.

The study cited a specific high end espresso grinder make and model used in the experiment using 'Turkish grind' burrs and was one of three such grinders evaluated as the other two had performance issues.

The study cited the grinder that was used in the experiments as a borrowed, used Mahlkonig EK43.

I read the study top to bottom though the data was not provided.

beanfish wrote: In summary, I think we need more and more specific information. Then we'll need to consider the pragmatic logistics of how to implement methods implied by the research. All of this, of course, means possibly changing our customary habits, and, if there's one thing you can be sure of, some will resist and some will embrace any such changes.

Cheers, James R.

Whenever I hear someone say 'we may all need to change our customary habits,' my radar goes up.
We don't have to change time tested processes because somebody did a study. I resist that type of Overton Window nudging.

The scientific way is to effort defeating a theory, not to rush headlong into embracing a theory.

One of the questions I have is: Who commissioned and who financed the study?