It's not a joke but completely besides the point. Most people aren't drinking butter-roasted coffee. Even if they did, the butter likely isn't adding any actual lipids to the final roast, just slightly altering the internal bean steam pressure, heat, and final water content. Any oils on the exterior would be vaporized at typical roasting temperatures. Also most heavily roasted beans will be shiny with oil within a few days of roasting, regardless of any added butter.
> Most people aren't drinking butter-roasted coffee.
I'm not sure how 'most people' is relevant to the discussion. Fact is that it is one of the largest GDP exports for Vietnam and 5th in the world [0]. Just because you don't drink it, doesn't mean millions of other people aren't drinking it.
"The main destination of Coffee exports from Vietnam are: Germany ($384M), United States ($257M), Italy ($230M), Japan ($186M), and Spain ($150M)."
If I take those beans "shiny with oil" (aka: butter), grind them up and make a cup of coffee with them (I personally go with an aeropress w/ steel mesh), then there is going to be oil (butter) in that coffee. In fact, I can see a slight oil (butter) sheen on the surface of the cup of coffee if I let it sit.
Sure, but you're making the assumption that your beans are shiny because of butter, while we know all dark-roasted beans will be similarly shiny regardless. You're not providing any clear evidence that butter-roasted beans retain any oils from butter, and frankly I'm very skeptical of that being the case. Have you ever tried heating butter to 300C in a pan? (Do not actually try this, you will start an oil fire and create lots of smoke)
