What is the latest on the storage of coffee greens? - Page 7

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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Stuggi
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#61: Post by Stuggi »

mikep wrote: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.
That's mildly true, but essentially nothing beats getting a strawberry variety that freezes well. Some look like the day you froze them when you thaw them up a year or two later... I think it has to do with the water content inside the strawberry. Some (like the variety my family grow) are really squishy and delicious when fresh, but after freezing the only thing you can use them for is impromptu jam (add a lot of sugar to the berries, heat in microwave). Other varieties aren't very good when fresh compared to the above variety, but they hold up to freezing like it's nothing. These berries are typically quite dry when fresh, which is why they don't turn into a squishy mash when you thaw them (since the water content is so low the expanding ice crystals don't break the cell structure).

If you apply this to greens, I wouldn't freeze them since if the cell walls are already broken it might interfere with the roasting (and it probably does since one of the cracks is when the water inside the cells breaks the walls, if I remember correctly). What I would do is to store them in burlap or cotton bags as close to zero degrees centigrade as possible in a controlled environment.
Sebastian "Stuggi" Storholm
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AmishMenno
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#62: Post by AmishMenno »

cannonfodder wrote:
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.
I was wondering what roaster you use and the green beans you might suggest for a person to get started in home roasting?

JimG
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#63: Post by JimG »

I've re-read this thread, but did not find any discussion of storing green's in poly bags in the refrigerator. Since I began roasting, I have simply stored my unroasted beans in the original thick poly bags that SM's ships them in. I rarely keep any green beans longer than 6 months.

At roasting time, I remove the bag from the fridge, pour out ~250g, squeeze most of the air out of the bag, and then return the re-sealed bag to the fridge.

This has not caused any problems that are obvious to me, but I lack a good basis for comparison.

Anyone else do this? Any reasons why I should do something different?

Jim

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another_jim
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#64: Post by another_jim »

There simply hasn't been much experimentation on alternative methods of bean storage. Mike Mc. compared vacuum packing and freezing over regular storage for a period of over a year, and it made a big difference. Terroir uses vacuum packing in mylar and freezing, especially for their "grand cru" coffees they intend to sell over a number of years. This does work, although there are sometimes some odd taste artifacts. Their conclusion is that it makes a big difference over several years, or if you can get to the coffee at the mill and vacuum pack it there to avoid the initial degradation in transport.

I think Terroir's observations make physical sense. The obvious model is that flavors decay exponentially, so that each has a half life. This means the more delicate flavors (i.e. those with half lives of a few weeks) get destroyed during shipping, those flavors that survive the six months from mill to roaster will be robust enough to last another six months in storage.

When I was cupping there, they had some Brazilian coffees shipped air express in Mylar. While these really weren't earth shaking coffees in terms of cup presence or power, they smelt like an entire flower garden, with a riot of very delicate aromas one normally doesn't get in coffee. Travellers to origin always report on this unique floral aspect that gets lost in shipping too.

There is now a public for $25/lb and up coffees. So there's certainly some gold in the green storage hills, if it can be done from origin out.
Jim Schulman

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