This is part of a freshness experiment of 5 coffees that were stored in ziploc bags and vacuum sealed that I started last August. Some of these samples were frozen. The objective was to see how green coffee loses freshness over a year’s time and if packaging preserves flavor.
All coffees were cupped blind on 8/23/09, roasted to a light-medium roast about 1 year from being sealed.
Coffees
Guatemala Huehuetenango
- Ziploc bag, sealed 8/12/08 , 11.6% moisture
- thin body, faded acidity, straw-like finish
- score: 70
- Vacuum sealed, sealed 8/12/08, 11.4% moisture
- overfermented berry, full body, some sweetness, medium acidity
- score: 80.5
- Vacuum sealed, sealed 8/12/08, 46 defects hand-sorted out, 11.4% moisture
- cedar aroma, flat acidity, parching finish
- score: 76
Guatemala San Jose Ocana
- Ziploc bag, sealed 9/11/08, 6 defects hand-sorted out, 11.5% moisture
- some fruit sweetness, cocoa aroma, round body astringent finish
- score: 77
- Vacuum sealed, sealed 9/11/08, 7 defects hand-sorted out, 11.8% moisture
- some sweetness, medium body, dry/ thin finish
- score: 78
- Vacuum sealed frozen, sealed 9/11/08,12 defects hand-sorted out, 11.7% moisture
- sweet, round body, moderate acidity, slight woody
- score: 82
Guatemala Fraijanes – Finca Agua Tibia
- Vacuum sealed frozen, sealed 9/11/08,12 defects hand-sorted out, 11.7% moisture
- medium body, soft, papery finish
- score: 79.5
Summary
Overall, coffees vacuum sealed and frozen retained a better flavor profile. The coffee lost some distinct aroma, acidity and sweetness qualities. They lost about 4-5 points from being stored for 1 year. The method slows down aging, but does not preserve or retain freshness.
Green coffee tasted best under 6-9 months from harvest. Storing coffee only prolongs inevitable aging, but does not add value. In short, nothing is gained by storing coffee for one year.
Moisture content in all samples were around 11%. Presumed coffee stored in freezer would have a higher percent moisture.
Vacuum selaed coffees retained a round fullness in the body and mouthfeel, eventhough lost acidity.
Coffees stored in ziploc bags lost the most flavor and 10-15 points over the year. The impact on aroma, acidity and sweetness were affected the most. The body was slightly diminshed. The aftertaste of the coffee became astringent, papery and rough.
Coffees that has defects removed produced a more uniform and consistent cup.
Under ripe seeds have a tight silver skin that won’t rub off. When I first learned about sorting, I had the tendency to leave those. The result was that by removing the other defects, I inadvertently increased the percentage of under ripe relative to the whole sample.
It’s a good idea to do a count of specific categories of defects then roast them separately so you can identify them easily in cupping later on.
Thanks Jaime for commenting.
Great suggestion about roasting defects separately.
I think early on I was quick to categorize any blemish as a defect where the SCAA scale of 10 broken beans equals to 1 full defect.