Vacuum sealed experiment update- sample #3, #4

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.

1 year project

Over time, green coffee loses moisture and starts to lose its character, particularly acidity and sweet flavors. The flavors begin to fade and tend to pick up a “baggy” flavor from the burlap bag

I have been pulling samples of various coffees and setting them aside for future tastings to see how they age and lose moisture. One experiment that I thought would be useful is to document how coffees taste over a year’s time to see how it fades in a year’s time stored in various materials. Commercially, green coffee is stored in jute bags up to one year. Some smaller roasters have been having coffee vacuum sealed at origin or at their roasting facility to retain some of the coffee freshness. Not everyone is in agreement because of cost, but coffee needs to breath and sealed bags can retain moisture and develop mold. Some are advocating burlap bags lined with a cotton bag since it will let the coffee breath, but not take on the jute aroma.

I will sample Colombia Platos Fuertes and store it in a burlap bag, cotton bag and vacuum sealed bag. I will divide the coffee up into monthly increments and cup them and post results with cupping scores.

I will measure the density and moisture of the green coffee each month with the outside temperature and humidity. Sacramento has hot summers, cool winters, but very low humidity. Interesting to see how the coffee changes throughout the year.

Vacuum sealed experiment update- sample #1, #2

I have been curious about green coffee stored in vacuum sealed bags and stored in ziploc bags. I have set aside several batches of green coffee over the last year, Vacuum sealed experiment, and will be tasting them over the following months. Yesterday was the first series of tastings.

• Coffees- 2 (Guatemala Florencia and Aqua Tibia 2008)
• Tastings- 2 rounds, blind
• Cups- 5 cups ber batch
• Roast- sample (light- after first crack)

Summary

Coffee stored in vacuum sealed bags had slightly better aroma in the green beans and roasted, ones that were stored in ziploc bags had a milder aroma. No difference in color of green beans. The main variable was that each roasted had some variations in flavor. When there are 5 cups, a few batches had a cup that was very sweet or bit winy so these lowered the score a bit. The coffees that were stored in ziploc bags had loss some acidity and sweetness, while the ones in vacuum sealed bags retained this quality better. There was not that large of a difference between sealed bags. I have 4 sample sets to test over the next two months.

Guatemala La Florencia ( purchased 5/08, cupped 4/09)

• Vac sealed bag: with defects sorted out
• Vac sealed
• Ziploc
  

Guatemala Fraijanes- Aqua Tibia (purhcased 5/08, cupped 4/09)

• Vac sealed
• Ziploc

1 year

This celebrates the one year anniversary of Home Roastery. This blog was an off shoot of my Coffee is Food blog. I specifically wanted a forum to discuss home roasting theory, coffees and tasting. I also wanted to include more pictures and be more visually interesting yet, I don’t update as much as I would like to.

I have learned a lot this year having to write about home roasting. Hope this year brings new experiments and discovering new techniques in roasting. Cheers.

Colombia Platos Fuertes Mico-Lots Huila

For the upcoming Summer Coffee Offering at This Joy-Ride we will be featuring Colombia Platos Fuertes. This coffee is a combination of small lots from the southern region of Huila in Colombia. We did several rounds of blind tastings from various countries and this stood out each time -fruit sweetness, balanced acidity with a clean finish.

I brewed the coffee in several different methods to see where the coffee tastes its best. Brewing the same coffee differently gives you a unique perspective each time. A friend poignantly described it like walking around a statue to view it from multiple perspectives.

For all methods I ground the coffee just before brewing, used filtered water just off a boil and measured carefully (10 grams of coffee to 6 oz water). For this coffee, I prefered a simple filtered cup which brought out the sweet fruit notes.

Drip (Technivorm)

Cherry sweetness, clean, complex and balanced acidity. Layers of sweet fruit-peach, plum, grape and cane sugar.

Syphon

Concentrated sweetness, molasses and caramel, marmalade, apricot and honey. Medium body with gentle acidity.

Chemex

Unripe apricot, slight dryness and bit papery.

French Press

Round and sweet flavor, consistent, soft fruit notes and crisp acidity in the finish. Overall, the flavors were a bit blurred together.

However you brew your coffee at home in your favorite mug, we hope you enjoy the Platos Fuertes for the Summer.

New toy

I have been wanting a moisture meter for some time and just picked one up. Moisture meters measure the moisture content in green coffee, typically ranging from 10-12%. This one is easy to use and provides quick results. It will be interesting to measure the moisture of a coffee over time to see how it loses moisture and impact on flavor. As green coffee ages it loses moisture and develops woody flavors and loses acidity. I hope to do some home experiments of measuring various coffees over a years’ time stored in various packing material- vacuum sealed, cotton bags and burlap.

Summer coffee offering

Looking for a new coffee for this Summer’s This Joy+Ride offering. Leaning toward new crop Central Americas. Maybe a new bag design with valve to keep coffee fresh.

Roaster updates

Looks like some new roaster updates that home roasters might be interested in.

Diedrich 1-Kilo Gas Roaster in production in the Winter.

The infamous San Franciscan 1 Lb Roaster is back

New moisture meters

Coffee Chemistry just updated their website and are now offering books and lab equipment. I have been wanting a moisture meter for some time and they are offering one from QC Lab. Looks interesting.

Ideally moisture in green coffee should be between 10-12%. I would be curious how this changes throughout the year for coffee. As a home roaster, this would be interesting to track this and affects on flavor. In Sacramento the humidity is relatively stable, but it does get very hot in the summer.

Tasting old samples

Had some samples of dark roast coffees laying around and have been tasting them over several weeks. Some were stored at room temperature and others frozen. Interesting to see what qualities are retained over time. Basically I am tasting for staleness. The coffee bean begins to oxidize and absorb oxygen.
The first qualities to fall off are the soft fruit and floral qualities of the coffee. Over a few weeks, the coffees begin to taste a bit edgy, rough and woody. The acidity becomes harsh and body is still present. Since these are dark roasts, this seems to carry certain qualities, but the subtle flavors begin to fade.

Some of the frozen samples were from over two months and they retained their quaility pretty well for a few tastings and then fell off soon afterward.