now brewing muddled!

July 17, 2005 – 12:45 am


rejiggered flush routine follows. given the sort of intra-shot temperature consistency that others are proving is quite possible, the previous flush-routine video clearly fell short of an adequately stable temp profile. one mind-numbingly simple mitigating factor: i was pulling water for 30 seconds without a portafilter attached — way more water, volume-wise, than actually is pushed through a puck of espresso over 30 seconds. there’s really only a need to regulate brew temp over the course of 2.5 ounces or so.

nothing worked, however, even though i tweaked flush and rebound times and simulated puck resistance for more accurate intra-shot temperature behavior. said futility led me to try the other flush method preached recently by everyone’s favorite quasi-pro, chris tacy, he of the intense and dream-like, weeks-long fiorenzato workout. bingo.

i now flush to exactly where i want the shot to brew at (again, not using a strict countdown, but augmenting the “one-mississippi” with an observation of the boiler pressure gauge). in other words, my flushes last roughly five seconds or so, but, depending on how heavily i’ve been using the machine, how hot the group is, etc., the moment i actually stop the flush depends on the needle’s behavior. after the hot-water hissing stops, i watch for the boiler needle to dip to its lowest point — usually just above 1 bar on my gauge. that’s where i stop the flush. the portafilter is pre-loaded and tamped (i do this during the flush, actually) and i load and lock and pull the brew handle almost immediately. this is just enough time for the boiler pressure needle to go from the bottom of its cycle to the very top (two seconds, at most). the resulting shot then features a stable brew temp that fluctuates no more than one degree.

video here. i shot two tracks — the grouphead/thermocouple readout and boiler gauge/cycle lights — and intercut them to show the whole flush-and-brew in detail. this process is much quicker than the previous routine — no rebound time. the temp profile for this particular simulated shot is a cool one — about 198.5 throughout. you’ll also notice that the “brew” stage is substantially shorter in this video, essentially because 2.5 ounces is the most water you’ll use. no need to stand around a watch the digits flip back and forth four ounces into the destestable venti size range…

thus, the intra-shot temp profile would at last seem fairly stable and highly replicable. used the zim to test the results with real coffee, and quite predictably i got a really good, yet very hard to define shot. it was delicious but “muddled,” you could say. not the easy distinction of key traits, though i partly suspect this quality to be inherent to this batch of beans. i procured them by different means, as you’ll recall. with better-regulated brew temp, however, shot-to-shot consistency was much improved, and the zim — which i used for its blatant sour-or-bitter traits when i miss the optimal brew temp — showed consistent signs of nippy sweeteness and alfalfa aromas (sticking more judiciously, again, to the flavor wheel). which brings us to the bean that caused all this renewed brew-temp obsession in the first place…

UPDATE: sorry. the musack, as you might have wondered, is a bit of quirky judy garland remix, i believe, by the brazilian girls and blossom dearie. somewhat transcendent for the minimalist thump-thump pastiche, i’d say, and a bewitching find on a local indie radio station. made a visit to itunes, i did, and bought it legally.