Hanna Neuschwander loves coffee. She adores it so much, that she's written a whole book about coffee roasters called Left Coast Roast. On a chilly evening this week, she had a small crowd of equally excited coffee aficionados join her for a home brew coffee class at 18 Reasons in the Mission.

The class started with a brain-teasing aroma sensory test that included sniffing little jars of unknown aromatics. The ones I felt were most difficult to identify, oddly enough, turned out to be the most straight-forward flavors, like apple and vanilla. Once the test was over, our senses were ready to take on the even more complex scent of coffee. We tasted coffee from Guatemala and Kenya and then learned the proper way to make coffee at home using a French press, the pour-over method, and the trendy AeroPress -- which supposedly has quite a following, but requires brewing hot coffee in plastic. Hmmm.

It was impressive to hear Hanna's daily coffee routine (which usually starts at 5am before work). She measures, in grams, coffee beans on a kitchen scale, grinds them in a burr grinder -- which usually produces a more even grind than your normal blade grinder -- brings her water up to 195 to 205 degrees Farenheit, and then slowly and methodically pours the water over her grounds to make the perfect cup.

That is some serious coffee making, not to mention attention to detail in the weeeee hours of the morning! What I found most interesting about the class was learning about the two methods for cleaning the cherry fruit off the coffee bean, called wet and dry processing. Wet means taking the cherry off first using a machine, then waiting a few days for the mucilage around the coffee bean to loosen, before rushing water over it to clean the bean. It sounded rather water-intensive and wasteful. Dry process means letting the fruit dry in the sun, sometimes on raised netted beds, which seemed much more environmentally friendly, and also gives the beans more of a chance to develop and absorb more sugars from the fruit, while they bask in the sunshine.

Apparently, many coffee shops consider the dry-processed beans dirty because of the possibility for fermentation and mold to occur while the coffee cherries dry, favoring the "cleaner" taste of wet-processed beans. Just another factor to consider the next time you're out for a new bag of beans.

While some elected to spit, I finished all my coffee, and left the class at 9pm, walking home with a happy coffee buzz while I hoped fervently I would be able to get some sleep.