Why exactly does a proper espresso blend come together into a thick ooze without much fuss - assuming you have all your basics accomplished - and then Single origin coffees and some blends are more finicky. Yet when one does nail a finicky coffee its taste could be considered transcendent.

Example: I pulled some triple ristretto Stumptown Hairbender. Beautiful thick brownish red ooze. Pretty delicious. Then I pulled some single origin Terroir Ethiopian Northern Italian espresso. This was finicky and not as thick of an ooze. Yet after wasting 3 or 4 shots I nailed it as a slow coming together dark molted stream. So, I understand the taste profile differences regarding balance and complexity, but why does the blending of beans seem to create a thicker crema and a fuller body. Not to exclude the rare transcendent SO that pulls in a balanced perfection.

One last thing - My experience of the Stumptown and Terroir SO Ethiopian was that the Stumptown shot was excellent straight while the Ethiopian had some real overwhelming dominate wild fruit action. Yet when I made a cap the Ethiopian shot reached trancendent levels cutting through the milk with sweet cinnamon and apricots WOW!. The Balanced Stumptown shot was just a good cap. This of course is why I want to load up on grinders to have different beans ready for different drink profiles!

So my main question is why does the blending create an improved physical character for espresso, ie, thick ooze that is not fussy to find.

Mark

Different species and varietals of coffee are biologically distinct. In the cup, these differences are further influenced by the type of processing (dry, wet, semiwashed, pulped natural, etc.). Blending different beans not only helps balance the flavor profile, but also impacts upon mouthfeel and other physical characteristics. More than any other coffee preparation method, espresso tends to amplify these characteristics. Wish I could tell you why...

And now for something more contentious. IMHO, it's harder to pull blends than single origin coffees, at least from a purely mechanical standpoint. When you blend a disparate group of coffee beans (different roast levels, arabica vs. robusta, aged/monsooned, etc.), the different bean characteristics make it trickier to get an even extraction. Although I generally prefer the taste profile of blends, SOs seem easier to pull. Mind you, I have not done any real experimentation with this, so consider it purely anecdotal evidence. It might make an interesting hypothesis for someone to test (hint hint).

Here's some Ethiopian Harrar from my last roasting session that didn't make it into a blend:



Got lucky and didn't even have to change the grind. A nice even extraction, thick and gloopy, and yum! a lovely straight shot.