Latest Posts

  1. A Second Look at 4 Ethiopian Coffees

    A Second Look at 4 Ethiopian Coffees

    We took a second look (and taste!) at 4 Ethiopian coffees from our 20% off sale.

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  2. Video: Sample Roasting with an Aillio Bullet R1

    Video: Sample Roasting with an Aillio Bullet R1

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  3. Video: Guatemala 2019 Coffee Clips

    Video: Guatemala 2019 Coffee Clips

    A few fairly low tech clips and some thoughts on coffee processing and coffee buying in Guatemala.

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  4. Video: Dry Process Coffee & Quakers

    Video: Dry Process Coffee & Quakers

    How we grade for the quality of our dry process coffees

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  5. Coffee Tasting At Sweet Maria's - Feb. 28th

    Coffee Tasting At Sweet Maria's - Feb. 28th

    Sign up and taste the difference between coffees roasted in different machines

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  6. New Postcards. Quakers: Resistant to Roast

    New Postcards. Quakers: Resistant to Roast

    Our new postcards. Look for one in your next order.

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  7. Podcast Episode #22 - Burundi Conversation with Alistair Sequeira - Part 2

    Podcast Episode #22 - Burundi Conversation with Alistair Sequeira - Part 2

    Part 2 of 2 - Continuing the talk about the coffee supply chain and other topics

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  8. Six Under Six - July 2018

    Six Under Six - July 2018

    Six great coffees. All under six bucks.

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  9. Podcast Episode #21 - Burundi Conversation with Alistair Sequeira - Part 1

    Podcast Episode #21 - Burundi Conversation with Alistair Sequeira - Part 1

    Part 1 of 2 - Talking about the coffee supply chain among other topics

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  10. Podcast Episodes 19 & 20: Kenya Coffee: Growing, Trading and Marketing

    Podcast Episodes 19 & 20: Kenya Coffee: Growing, Trading and Marketing

    A while back we had Mary Maina Manyeki visit us in Oakland, and had a great conversation about her experiences as a Kenya coffee farmer.

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  11. The New Postcard

    The New Postcard

    We are really proud of our latest postcard because it captures an aspect of one of Tom's photographic projects; shooting realistic macro photos of coffee beans.

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  12. Sweet Maria's Green Coffee Sample Sets

    Sweet Maria's Green Coffee Sample Sets

    The ultimate order-ahead-of-time-pre-holiday-non-procrastinator-thing-you-can-buy-from-us-right-now

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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

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