Happy Sunday − and welcome to the best of The Conversation. Here are a few of our recently published stories:

• Feinstein’s death raises the question: How are vacant Senate seats filled?

• Lost in the coffee aisle? Navigating the complex buzzwords behind an ‘ethical’ bag of beans is easier said than done

Is there a better way to start the day than with a cup of coffee? Or in my case, a cappuccino, brewed with freshly ground beans in my Italian espresso maker. I’m a bit of a coffee snob who loves the aroma, taste and routine of making my morning cup of Joe, especially on a Sunday.

But I hadn’t thought much about the chemistry of coffee – nor did I imagine it could help teach chemical engineering. For over a decade, William D. Ristenpart, a chemical engineer at the University of California, Davis, has done just that. He teaches his students about energy use, the kinetics of chemical reactions and the principle of mass transfer, all using experiments done with a Mr. Coffee drip brewer.

He explained his Uncommon Course – the name of our occasional series on out-of-the-ordinary college classes – for us last week in an article edited by science editor Mary Magnuson, giving me one more reason to appreciate why coffee is extraordinary.