Some places just seem to put out coffee and espresso that tastes burnt. Why do they do that? Where does the burnt taste come from? Is that just one barista making a mistake, or is it the way the place is managed?
The basic answer is: too much heat somewhere in the process. Coffee can gather a burnt taste from three areas: 1) During roasting, 2) During grinding, or 3) During extraction. Since baristas only control the extraction process, burnt taste is usually the fault of company management policies.
Why would any company put out burnt coffee? Money! (Didn’t see that coming did you?) Other blogs go into roasting more in depth, but the bottom line is if you buy cheap-ass beans you want to roast them more to even out and cover up the imperfections in the beans. Also, massive roasters tend to flash roast their beans (two minutes instead of 18 minutes) and this tends to over-roast the outside and under-roast the inside. Larger coffee companies and nasty coffee huts may buy cheaper beans and then try to cover up the coffee taste with more syrup.
My dad had a table saw and he never liked to buy new blades, so to cut a sheet of plywood took a long time and the edges were always burnt from friction. Same thing with grinder blades – if they are dull they can overheat the bean. Also, grinders with small motors tend to spin at higher RPM’s which can introduce unneeded heat to the process.
I’ve seen a lot of bad barista habits (in other shops). One error under trained baristas make is to pack a shot, put it in the group head, and let it sit there while they get their milk ready. The group head is around 200 degrees and the shot will simply start to bake. Anything in a group head longer than about 45 seconds will start to taste burnt.
Don’t put up with burnt coffee. Go to a good coffeehouse that gets good beans that are roasted properly and enjoy the real taste of the coffee.