George Howell and Terroir Coffee: Freezing Green

[Alistair]

in coffeegeek podcast 004 George Howell of Terroir Coffee discusses freezing green coffee. From thier website:

As soon as raw coffees arrive to our warehouse we remove them from their jute bags and repackage them in vacuumed foil bags. Then, when the green coffee reaches its full maturity, it is frozen at 40 degrees below zero. The coffee's sweetness, aromatics and liveliness are all retained for months, even years.

This is just one of the reasons Terroir is on the cutting edge in the coffee industry. Yet until now I imagined that George's methods were much more advanced than what he describes in the podcast: just put your green coffee in one of those vacuum sealing home units, and throw it in the freezer!

Ok great, but I still have some questions. First, home freezers are usually only 0 to -8 degrees fahrenheit, and chest freezers up to about -20. Is this really cold enough for long periods?

George seems really convinced, and excited about this method, but I'm wondering - there must be some sort of physical change in the green coffee when it is frozen?

Are there special handling instructions when the coffee comes out of the freezer for roasting? What if the coffee is taken out and then put back to freeze without opening (like for shipping)?

Perhaps George will just swing by and answer all my questions. yes, that would be nice.

alistair.

[Robert Goble]

I think that we're just at the beginning of how we think about, and eventually address issues relating to green bean storage etc…

On its face, the freezing of green seems like a no-brainer. Of course it makes sense to do this. I think we've all experienced what happens to our favorite coffees as they age as green in storage.

I too was somewhat surprised that George was saying it's as simple as bagging it and dropping it in the freezer. George may have some trade secrets of his own, but I'll venture the guess that as time goes on, the protocols and methodology regarding the hows, whens and whys of freezing green will become much more defined and backed by sound science.

I can imagine factors like how quickly a bean is brought to its target temp (both frozen and then refreshed from storage) as well as the specifics of those temps, with perhaps even variations for specific origins and varietals themselves will be discovered through the process of developing this new technology..... I can imagine some endless iterations and nuances that could be explored by variations in all the factors to do with bean storage becoming part of the literature in years to come....

I'm convinced, based on his word, that George is pioneering here, but others will have to follow --- and relatively soon too. And that will open up all kinds of new possibilities.

Rob

[Alistair]

some discussion over at portafilter.net about green freezing: http://www.portafilter.net/2005/07/podcast-6.html

[Alistair]

George Howell responds to comments on portafilter.net:

http://www.portafilter.net/2005/07/podcast-6.html

[Robert Goble]

There are 4 or 5 comments "missing" over there

[Alistair]

There are 4 or 5 comments "missing" over there

?

[Robert Goble]

The last time I looked there were 25 comments (unless my mind is going). Now there are 20. Maybe my recollection is all messed up. If so, please don't tell my girlfriend. I have a hard enough time winning arguments with her now -- I can't afford for her to know I've actually lost my mind. Keep the faith brothers

[nick]

It's my party, I can cry if I want to.

Sorry for the confusion. Had to do some housekeeping is all.

[barry]

i would be concerned about cellular damage due to crystal formation. green has a lot more water in it than roasted, and it's hard to get around the ice issue.

[Alistair]

do you think Terroir has 'gotten around the ice issue'?

the coffee is fantastic, isn't that the point?

[barry]

i don't know if they've gotten 'round it or not. how's the shelf-life? i've heard a couple of reports that the coffee is great for a day or two after roasting and then quickly goes away (which would be consistent with cell damage).

[SL28ave]

It'd be interesting to quantify cellular damage caused by roasting into 2nd crack vs our gently roasted, frozen green. Perhaps Terroir beans have a relatively longer shelf life?
A speculation of mine .

I was intrigued by the post concerning a shortened shelf life too. But that was one person's reaction out of many dozens. Regardless, I still desire that kind of feedback very much, and we'll look further into it!

[Robert Goble]

Peter, without giving away trade secrets --- do you guys actually have any data? Are you still collecting data at this point and using it to further refine or define what you are doing? At what point in the development process do you see your current methods - early, mid, or end? What's next for you?

[tonx]

i propose a simple experiment - one i might undertake myself in the coming weeks:

roast two batches of coffee (preferably a small lot washed coffee of exceptional cup-to-cup consistency) - same batch size, same precise profile. Batch 1) is normal, batch 2 has been frozen for 2 or 3 days.

My initial suspicion is that most of the cellulose structure of the bean is hardy enough to resist "damage" from freezing/thawing, but from looking at electron micrograph images I wonder if there wouldn't be some effect of displacing the lipid blobs inside the cell walls or to tenderize some of the inner-cell protein clusters much like freezing meat has a tenderizing effect. I know jack squat about chemistry though so this is just bullshit speculation.

My first guess would be that the batch that had been frozen would come across differently on the cupping table, though not necessarily in a negative way.

Have you guys at Terrior done any direct comparison in this way?

[barry]

fwiw, i'm not dissing the notion of freezing green, only pointing out that there are more issues with that than with freezing roasted. "freezing" isn't even the correct term to use with roasted coffee; "low temperature storage" is more accurate. green, though, gets frozen, because of the water content, and water does fun things when it freezes and thaws.

it's certainly something to explore, and i'm glad someone of george's stature is working on it.

[Alistair]

clearly the suggestion is something must change, so the question is what. i highly anticipate the results of roasters experiments in the simple method of vacuum pack freezing and blind tastings.

until then the only people qualified to speak are Terroir. the rest of us sound ridiculous.

[malachi]

Why must something change?
What is the problem being solved?

[Alistair]

I meant in the freezing process, something must change in the green coffee. That seems to be the suggestion of everyone who has responded lately to this topic (here and elsewhere).

[SL28ave]

do you guys actually have any data? Are you still collecting data at this point and using it to further refine or define what you are doing? At what point in the development process do you see your current methods - early, mid, or end? What's next for you?

We're definitely at an "end" in the short term, because right now freezing is certainly better than not. The question, "to freeze or not to freeze?" is answered.

We are at a "beginning" in the long term, because so many details are to be had out (we have developed a fairly detailed/intensive process, but could still use some tweaking). These details are not strictly related to freezing, but also to the entire concept of "green freshness" in general. I urge you all to boldly move forward on "green freshness" (through freezing or not), and I believe it will be very rewarding.

We have volumes of data from cuppings, which is the primary data. We're working towards data on the physical/chemical changes incurred by freezing.

[SL28ave]

Have you guys at Terrior done any direct comparison in this way?

We have, though I'd like to do it a few more times. I'd love to hear the results of your experiments.

I'd urge you to vacuum seal the frozen beans, and defrost in open air. I personally wouldn't go anywhere near 2nd crack either.

[Robert Goble]

Does your data include blind or double blind cupping notes?

(I am a believer BTW.... and I really appreciated your answer of a couple posts up).

How soon (on arrival of green) are you vacuum sealing and freezing? Immediately? And do you ever purposely age pre or post freezing?

[malachi]

at an "end" in the short term, because right now freezing is certainly better than not. The question, "to freeze or not to freeze?" is answered.

OK...
Why is it better?

[SL28ave]

Our goal is to present a fresh fruits, nuts, and flowers flavor profile. If not cared for over time, it will quickly become muddled by an "agey" profile; according to our cupping table. There are other options to freezing, but none have been presented that better maintain that "fresh" flavor profile I personally desire. So, I stand by my statement for now.

[Alistair]

Why does Terroir make such a big fuss about storing green coffee?

"Raw coffee has a shelf life. Raw coffee gets old over months; some coffees age far more rapidly than others. The effects of aging are very discernible in the coffee you drink. When freshly harvested, a coffee's liveliness and floral aromas (if it has any) will be emphasized. As it begins to age the coffee deepens at first, developing body, without harming other positive attributes. Then the coffee goes into decline. Certain floral aromatics disappear first, and then sweetness diminishes progressively as an unpleasantly sour woodiness takes over. Excess humidity or dryness, heat and light all accelerate green (raw) coffees' loss of quality."

"Softer, lower-grown coffees lose their quality faster than higher grown, harder coffees. By December all coffees grown north of the equator, no matter how high-grown, start losing their aesthetic individuality and their sweetness, becoming more and more unpleasantly woody. These include Ethiopian, the best Kenyan (two harvests - right at the equator), all Central American coffees, most Colombian coffees (some areas are south of the equator), and Caribbean coffees. Yet new crop coffees are months away. Hawaiian Kona is harvested earlier and is already appreciably losing sweetness by early summer."
http://www.terroircoffee.com

[malachi]

Or you can only roast and sell coffees at their peak and buy coffees throughout the year, changing your offerings over time and season to season -- in essence accepting (or perhaps respecting) the agricultural nature of the product)....

I love good peaches in season. There is almost nothing like them. But they have an incredibly short shelf life and their peak season is very short as well. Is that a problem? Is the solution to freeze peaches so I can eat them year round or to be satisfied with eating peaches during peach season and asparagus in asparagus season and beets in beet season etc etc?