I’ve read estimates ranging from 15-20 square feet for Hole in the Wall Coffee, a tiny North Beach window that Zac Green opened in 2014 just uphill from Washington Square Park. Self-described San Francisco “coffee raconteurs” reside under a blue awning and prepare pourover coffee, cold brew, tea and coconut juice for customers at just a couple stools and tiny sidewalk tables. A barista told me that HITW has beans roasted exclusively for them in San Leandro, which also helps fuel a sister coffee bar in the Mission District. They brew three different roasts: Blonde, Brunette, and Redhead. I opted for Blonde, the lightest roast with good acidity and a hefty caffeine kick that girded me for hill-climbing.