A Beginner’s Guide to Roasting Coffee at Home

Of note, the smoke associated with coffee roasting isn't exactly healthy.

https://www.jsonline.com/story/archives/2019/09/18/coffee-ro...

> Tests at two midsized Wisconsin roasteries that agreed to let the news organization analyze the air in their production areas found diacetyl levels from unflavored roasted coffee that exceeded safety standards proposed by the U.S. Centers for Disease Control and Prevention.

> In some areas, by nearly four times the concentration.

> Workers exposed to similar levels at popcorn plants suffered serious, incurable lung disease.

> "If roasters our size knew what this was, they would be super proactive," said Matt Earley, co-founder of Madison-based Just Coffee Cooperative, one of the two roasting operations that allowed the air sampling. "There needs to be hyper-awareness among people roasting and grinding coffee."

> ...

> The degree of exposure in an establishment depends on a variety of factors such as ventilation, number and size of batches roasted, how much coffee is ground on site and what type of equipment is used.

> Grinding coffee increases the surface area and releases higher concentrations of diacetyl than roasting alone, according to the Journal Sentinel samples. The government's study of the Distant Lands plant in Texas also found some of the highest levels in the breathing zones of workers who ground coffee.

> Inhaling diacetyl has proved deadly. Diacetyl attacks and obliterates the lung's tiniest airways, causing a disease known as bronchiolitis obliterans. As the body tries to heal, scar tissue builds up and blocks the airflow. The damage is irreversible.

I've never been able to produce consistent results with these DIY home roasting methods. We only attempted it because someone was gifting us green coffee beans. Overall it seems like more trouble than it is worth, even with free beans.