With so many variables influencing the quality of an espresso, consistent quality standards are difficult to achieve even within the same café. Baristas on different shifts can produce significantly different results. Even small adjustments to equipment - such as the grind of the coffee, or changes in the amount of water flow through an espresso machine - can make a huge difference in flavor.
Where possible, we've recorded my impressions of the consistency of each reviewed establishment using the following ratings:
As with restaurant chefs, producing consistent results is a key measure of success. While there are many options for dubious espresso in San Francisco, surprisingly most every establishment we retested did not vary significantly. The good news is that the best places do not appear to be flukes. The bad news is that any place serving foul espresso did so with notable regularity.
Even so, because inconsistency is often a notorious flaw, the establishments in this guide that scored the highest were all retested at different days and times to ensure accuracy. The most significant variances we discovered were shift differences between an excellent barista and a good one. We've documented these findings in the notes section of each review as appropriate. Also, where there were variances, the ratings in this guide reflect the median of any ranges of quality factors we encountered at a specific location.