What is the latest on the storage of greens?

[cannonfodder]

I know this has been hashed around on CG with many opinions expressed. I prefer to get my data from HB, less volume and more substance. But on to the question at hand.

Being a home roaster, I spend most of my home roasting time searching for that perfect bean for the perfect blend. Knowing that greens are an agricultural product and subject to change from year to year and lot to lot, once I find a bean that hits my fancy I like to order a stock.

To date, I have followed the common belief that greens should be stored in a cool, dry, dark place. I keep them in a cupboard in cotton bags to allow for some circulation, let the beans breath. Lately I have seen quite a few indications that the new preferred storage method (a 'stock' is about one years worth) for long-term storage is to freeze the greens.

What say the bean gods??

[another_jim]

George Howell freezes his greens, and Sivetz recommends it. I recall Mike McGinness did a controlled experiment and concluded the technique had merit.

On the downside, I've heard anecdotal reports of frozen beans aging must faster post-roast than their unfrozen equivalents.

The theoretical objection to freezing greens (as opposed to roasted coffee) is that they contain about 10% to 15% water. This water will crystallize when frozen and damage the cell walls. I have no way to judge this.

[miKe mcKoffee]

George Howell freezes his greens, and Sivetz recommends it. I recall Mike McGinness did a controlled experiment and concluded the technique had merit.

On the downside, I've heard anecdotal reports of frozen beans aging must faster post-roast than their unfrozen equivalents.

The theoretical objection to freezing greens (as opposed to roasted coffee) is that they contain about 10% to 15% water. This water will crystallize when frozen and damage the cell walls. I have no way to judge this.

That's a negative. I vacuum seal greens at in cool room temperature, not frozen. My theory was/is closest to being still in parchment, keeps any and all odor contamination away, and keeps moisture content stable. Did a 4 year greens vac storage test. (Costa Rican La Minita from SM was the control green.) The 1 year vac sealed actually out cupped the current crop, this was Tom's rating.

The fresher the greens the longer they'll be good vac stored. I've had a particular two year vac sealed Kona green, obtained while in Hawaii at the Estate right from milling to green, be better than a dozen other current crop Kona including that years Cupping Competition winner. Three years starts being noticably off. Four years toss it. Greens obtained normal channels 1 to 2 years max since they've already been out of parchment quite some time traveling here and there before we get it. Again, this is vacuum sealed but but not frozen. I vacuum seal all my greens as soon as I receive them regardless the source.

Roasted coffee stores well vacuum sealed and frozen for emergencies or to be waiting returning from vacation etc. Tom (of SM) test some 6 months frozen with positive results. When using only take out what you'll immediately grind, immediately and re-vac and back to freezer. (Sivetz is/was a big proponent of freezing hermetically sealed roasts. Don't recall him ever freezing greens though.)

[windowrx]

My own very humble opinion is that anything I've tried, be it meat or vegetable, has not tasted as good after being frozen and thawed so I don't feel that coffee would be any different. I just can't see how freezing would not change something if even in a small way. I know that some very respected individuals have been doing this with good results but I believe one of them is freezing to -40*. I could never duplicate this at home.
My unrefined palate probably couldn't detect any change freezing might cause but using that same reasoning I probably can't tell any difference in the flavor of green stored under normal conditions for a reasonable period of time. I know that so far I haven't seen any change in the beans I've had for nearly a year so I'll keep storing them as I have been.

[another_jim]

That's a negative. I vacuum seal greens at in cool room temperature, not frozen. ...

Oops, remembered it wrong. I did remember correctly that you did some extensive testing on greens storage, and should be considered a maven on the topic.

[AndyS]

The theoretical objection to freezing greens (as opposed to roasted coffee) is that they contain about 10% to 15% water. This water will crystallize when frozen and damage the cell walls. I have no way to judge this.

Probably the only way to judge it is with blind testing between "frozen" beans and never-frozen beans. It's not clear whether low temp storage will make any difference, since:

1. a good portion of the water (1/2 to 1/3, according to Illy) is bound or weakly bound inside the beans, so it may never freeze, and
2. the cell walls are blown all to hell in roasting anyway. (Obviously, if they're "pre-blown all to hell," it may affect the roast negatively).

[AndyS]

Roasted coffee stores well vacuum sealed and frozen for emergencies or to be waiting returning from vacation etc. Tom (of SM) test some 6 months frozen with positive results.

I don't doubt the efficacy of sealing and freezing, but wonder about the vacuum processing. If you pull too high a vacuum you'll certainly strip off desirable volatiles. A gas-flushing process that used low intensity vacuuming might be best.

[miKe mcKoffee]

I don't doubt the efficacy of sealing and freezing, but wonder about the vacuum processing. If you pull too high a vacuum you'll certainly strip off desirable volatiles. A gas-flushing process that used low intensity vacuuming might be best.

Yes I've heard the theory vacuuming roasted coffee beans sucks out the volatiles. Yet roasts mason jar FoodSaver vacuum sealed directly from cooling and four to six days vacuum rested served to an advanced cupping palate like Tom Owens suggests otherwise. I've done so on multiple occasions.

[malachi]

Buy smaller amounts -- enjoy the fleeting, ever-changing, seasonal reality of an agricultural product.

Respect.

[miKe mcKoffee]

Buy smaller amounts -- enjoy the fleeting, ever-changing, seasonal reality of an agricultural product.

Respect.

After doing that four year greens vac storage test that's exactly what I've done. At that time greens stash had surpassed 250#, about two years supply or a bit more. Since doing the test I've reduced stash down to a current managable 108# right in my 100# target years supply. That's with adding about 50# this year. Goal being running out of any particular varietal just as the new crop coming in. Yet I'll still go through the hassle (and additional expense) of vacuum bag sealing the greens so 11 to 12 months after getting them as they're running out they'll be as fresh as possible.

[AndyS]

Yes I've heard the theory vacuuming roasted coffee beans sucks out the volatiles. Yet roasts mason jar FoodSaver vacuum sealed directly from cooling and four to six days vacuum rested served to an advanced cupping palate like Tom Owens suggests otherwise. I've done so on multiple occasions.

Mike, I think we're oversimplifying a complex subject. "Vacuum-packing" means different things to different people.

I have zero experience with a FoodSaver machine, but a lot of experience with industrial vacuum packing equipment that leaves residual oxygen at less than 0.5%. I'd bet the FoodSaver pulls a really crappy vacuum by industrial standards. Sivetz talks extensively about this on his website. His patent combined very low residual oxygen (well below 1%) with freezing. He claims that if you don't get the residual oxygen content really low, there's no point in pulling a vacuum at all.

Why they issued him a patent for rewarmed technology that was freakin' obvious anyway is another matter....

So I guess what I'm saying is that the FoodSaver may not (1) pull enough vacuum to strip off volatiles, and (2) make a difference in shelf life.

What do your cuppings say about FoodSaver sealed samples vs. regular samples? (I'd be happy to wrong about this if your blind tastings show the FoodSaver to really make an improvement).

[cannonfodder]

Well, I will chime back in with a couple of observation/comments. In regard to the FoodSaver vacuum pack, it does make a difference for my vegetables. I grow a moderate sized garden (don't remember the last time I purchased vegetables) and I vacuum pack my beans, corn, broccoli, meat, fish (I do a lot of hunting and fishing as well). It makes a very big difference. I gave up canning because I get much better preservation vacuum packing and tossing it in one of my deep freezers (yes I have two, told you I put in a big garden, bunch of salmon and a few deer every year).

Now to reflect upon Malachi's comment. Being an amateur farmer of sorts, I am very familiar with the seasonality of agricultural products. When I have company I cook some of my 04 corn because it was a much better year than the 05 crop. The seasonality of coffee is part of what makes home roasting and blending enjoyable to me. That is also why I purchase no more than a years worth of greens. I just want to make sure the last roast of my 05 Yemen is as good as the first roast. Given the short time frame it may be a moot point.

I am watching the Chicago football game, boy, does it look cold up there!

[another_jim]

I am watching the Chicago football game, boy, does it look cold up there!

Most common thing I heard all week was wisecracks about global warming; this is cracking up to be the coldest winter on record here. Good for the Bears though, by the second half, Vick had trouble just holding the ball, never mind throwing it.

[mikep]

The theoretical objection to freezing greens (as opposed to roasted coffee) is that they contain about 10% to 15% water. This water will crystallize when frozen and damage the cell walls. I have no way to judge this.

I seem to remember an episode of Good Eats where it was claimed that freezing strawberries in a typical freezer was problematic because the ice crystals are formed fairly slowly, so they grow large and damage the cell walls. Alton Brown claimed that if you performed a quick freeze on strawberries by close contact with crushed dry ice, the ice crystals that form inside the berry are smaller, so they are less damaged by the time you thaw them.

[skyryders90]

I seem to remember an episode of Good Eats where it was claimed that freezing strawberries in a typical freezer was problematic because the ice crystals are formed fairly slowly, so they grow large and damage the cell walls. Alton Brown claimed that if you performed a quick freeze on strawberries by close contact with crushed dry ice, the ice crystals that form inside the berry are smaller, so they are less damaged by the time you thaw them.

Alton Brown is genius.

[malachi]

I just want to make sure the last roast of my 05 Yemen is as good as the first roast.

That's easy to do.
Roast it all within the optimal window for the green.

[malachi]

... so they are less damaged by the time you thaw them.

I would never argue that green coffee which was vac packed and frozen will taste better when roasted 12 months later than that same green allowed to sit at room temp exposed to air.
But there is no way it will taste as good as if it were simply roasted at its peak.

Personally, I would rather drink a wonderful coffee at its peak during a month out of the year and then remember it for the next 11 months with longing than drink a degraded version of it for 12 months out of the year.

[DavidMLewis]

This raises a question I've had for a long time. Aside from the extra cost of shipping, why isn't specialty coffee shipped and stored in pergamino, then hulled just before roasting? While I thoroughly agree with Chris on this, I can't help but feel that most of us have actually never had a coffee at its peak, i.e. as it would be if it wasn't sitting on a truck and/or ship for months before we got it.

Best,
David

[another_jim]

This raises a question I've had for a long time. Aside from the extra cost of shipping, why isn't specialty coffee shipped and stored in pergamino, then hulled just before roasting? While I thoroughly agree with Chris on this, I can't help but feel that most of us have actually never had a coffee at its peak, i.e. as it would be if it wasn't sitting on a truck and/or ship for months before we got it.

Good question. Of course it implies that the pergamino actually protects the bean from damage or taste degradation

Suppose it does. My guess is shipping weight. The whole coffee supply chain is based on "Coffee as commodity" model, where costs are minimized regardless of quality. We're seeing specialty coffee develop its own supply chains now; auctions, relationship coffees, and importers who handle these coffees exclusively or as a separate division. But I've never yet seen a specialty roaster set up to hull the beans; maybe that'll be coming.

I'm a sceptic when it comes to how badly green coffee degrades when gently stored -- I've not noticed much in mine over six months to a year. However, a key fact for me is that decafs, no matter how good out of the plant (and some can be very good indeed) are undrinkable about 4 to 6 months after processing. Decaf coffees are soaked, then dried, during the decaffeination process. For many coffees, transport involves getting heated and steamed in an often several month long trip from origin to the temperate zone dock in the destination country. My guess is that the worse this is, the less well the coffee stores. I've found Yemens, for instance, which get prepped and transported in very dry climates, hold up for surprisingly long periods -- A bag end of Barry's famous Haimi was still a strawberry/chocolate bomb when I found it after two and a half years storage in my apartment.

[cannonfodder]

That's easy to do.
Roast it all within the optimal window for the green.

Which brings up the next question, what is the prime age for green? Understanding that there will be differences in shelf life from origin to origin, what is a good rule of thumb?

I have seen multiple posts that suggest greens have several years of shelf life if properly stored. I don't know that I agree with that but I have never kept a green longer than one year. My normal shelf life is between 6 and 12 months. So given my rate of consumption, should I even be concerned about storage? My cotton draw string bags have not disappointed me yet so is there a reason I should change?