Latest Posts

  1. New Video: Burundi. Visiting Dusangirijambo Cooperative

    New Video: Burundi. Visiting Dusangirijambo Cooperative

    Take a tour of Dusangirijambo

    Read More
  2. Guatemala: Buying Overview + Roasting Fundamentals Review

    Guatemala: Buying Overview + Roasting Fundamentals Review

    An overview of our buying in this ever important coffee origin with links to roasting fundamentals.

    Read More
  3. Sweet Maria's Staff Picks: Featuring Julio

    Sweet Maria's Staff Picks: Featuring Julio

    Read More
  4. New Video: Air Roasts - Closeup on Roast Levels

    New Video: Air Roasts - Closeup on Roast Levels

    Lighting and other factors can help you look at air roasted coffee

    Read More
  5. Moka Java: Re-Constructing the World's Oldest Blend

    Moka Java: Re-Constructing the World's Oldest Blend

    The long, storied past of Moka Java blend and how to blend it yourself.

    Read More
  6. Roasting Fundamentals: Getting Started with Decaf Coffee

    Roasting Fundamentals: Getting Started with Decaf Coffee

    Tricky to roast but better tasting than ever.

    Read More
  7. Ethiopia Organic Dry Process Two Ways: Regular vs. Decaf

    Ethiopia Organic Dry Process Two Ways: Regular vs. Decaf

    An amazing dry process Ethiopia now available as both regular and decaf.

    Read More
  8. Quakers and Taste - 2020 Sensory Summit

    Quakers and Taste - 2020 Sensory Summit

    Read More
  9. Rwanda Mutovu Video Tour: Incremental Improvements, a Competition-Level Cup

    Rwanda Mutovu Video Tour: Incremental Improvements, a Competition-Level Cup

    Small improvements at Rwanda Mutovu washing station has led to a consistent, competition-level coffee.

    Read More
  10. Sweet Maria's Staff Picks: Featuring Ryan

    Sweet Maria's Staff Picks: Featuring Ryan

    ...because we have our favorites too.

    Read More
  11. Rwanda Kageyo : Fresh Coffee and a Fresh Infrastructure Project

    Rwanda Kageyo : Fresh Coffee and a Fresh Infrastructure Project

    We're helping fund a buildout at the Kageyo station and you can help too!

    Read More
  12. Honduras: Coffee Sourcing Challenges

    Honduras: Coffee Sourcing Challenges

    While we may have struggled to find a consistent source in Honduras, we continue to come up with good coffee. Find out how.

    Read More

Coffee Damage under UV Light

Coffee Damage under UV Light

Coffee Damage under UV Light, originally uploaded by sweetmarias.

Ultraviolet light is useful to see problems with coffee like mold and bacteria, but these are things that affect low grade lots that are already quite damaged. However, when I suspect drying problems with coffee, I check it out anyway. Some recent Sulawesi wet-hulled lots have been very surprising under UV light, and in general UV shows the problems with the wet-hull process overall (although our Blue Batak Sumatras fare well under UV light. This was a surprise. An Ecuador
Cariamanga lot with a nice cup, but some odd off notes cropping up way too often. The green coffee loots PERFECT. But under UV light, small nicks, little marks were I suspect the pulper scraped against the coffee seed due to misadjustment. Then in fermentation the damaged areas are in contact with mucilage and bacteria, rather than being protected by the parchment layer. The result is some off cups, but mysterious since there was little clue under normal light. I
could not get the coffee to "light up" completely under UV for the photo so the arrows assist in seeing the glowing areas, and then the 1 little pulper kiss marks can be seen.
--
-Tom

Comments