I have mostly played with recommended single origin espresso greens. I will occasionally roast up some of what are considered classic components and post roast blend at various percentages but am still very much in the infant stage. My basic understandings are to consider sweetness, acidity and body along with the flavor possibilities as a start. I roast taking these factors into consideration. I know it's recommended to try as many of the best blends from the best pro. roasters as possible but with the overall expense of my coffee/espresso/roasting habit I just haven't done so.
***Note: as some of us are beginning to work on a sample for First annual HB roasting event some may think this thread is inappropriate. But since the goal is more about improving our hobby and less about the prize I'm posting this and hope we can have some good general discussions and avoid talking specifically about our event samples.***

Old school espresso blending called for about 50% Brazil, maybe 25% of heavy stuff, Sumatra, Robusta or monsooned Indian coffee, and 25% of something high grown, a central or East African. If you can do single dose grinding, develop a blend like this by roasting up a big batch of Brazil, and small batches of everything else, then start with all Brazil shots and add bits of the others until you get something you like.

New school espresso blending, as seen at Barista competitions, is all over the place. Even the Brazil is no longer mandatory. I like to start blending espresso by mixing light roasted brewed coffees that have cooled to room temperature. While hot brewed coffee is nothing like espresso, the cooled cup gets close to the same flavor balance. Blending here is fairly easy -- take a small cup and a spoon, put a spoon of this and a spoon of that into the cup, and slurp.

Remember, there's no such thing as a best blend, there's no need for 12.7% of this, and 22.95% of that -- rough proportions are fine, and have fun.

Jim, blending cooled coffee is a good tip, thanks.

I'm pretty new to blending as well, but I've found that just by roasting five or six different single origins and blending per shot was a lot of fun. I had roasted up different origins for a coffee tasting at work and then later for a party where I normally don't have that many origins on hand.

Jim, when you say "new school blending", does that include the less bright blends like Klatch's Belle or Blue Bottles' Hayes Valley Espresso? Or are they the Brazil based old school? It thought I read somewhere that these fuller bodied, less bright, chocolatey style blends were indicative of American style espresso. Or was that yesterday's news and the brighter, fruitier blends are the new school? I'm so confused

Actually these two blends are what I'd like to shoot for but neither roaster gives you a clue of what's in those blends. Any ideas?

Cheers.

Mellow nuts, caramel or chocolate flavored espresso, with a twist of fruit, is old school espresso, whether US, Italy or anywhere else. The US variant is higher doses and punchier flavors, mainly because the same blends are used in milk; but the basic recipes for a classic espresso blend remain similar.

The current trend is to reduce the number of ingredients, and use more complete coffees that can stand on their own. There are now quite a few commercial blends with just two or three ingredients. These vary year to year. I do not know if Belle has changed in this way; but my local blends, Black Cat and Red Line, have changed quite dramatically each year for the past three or so, mostly in response to finding a great new coffee each year.

This is really different from someone like Illy, who will use a half dozen each of Brazils, Centrals, and Indian beans to achieve year in year out consistency. The Brazilian coffee board itself has sunk years of research into chemical noses and production line mass spectrometry to automate the creation blends from many Brazilian beans to get just the right flavored espresso base wanted by the big Italian roasters.

For the competition, I tried to pick coffees that can be used in lots of different ways. There are 15 possible SO and blend combinations (without considering proportions). My guess is that every one of them would make a good shot with the right mix of the right roasts.

I do the coolish coffee tasting/mixing and find it does have some good correlations. I also try blending by shot. I think I have a pretty wide zone for what I like too. Tend to like higher acidity in hot weather and heavier ones in the winter. I can like the old school 50% brazil or even something like a Kenyan and a DP central. As long as there's enough sweetness and some body. I've been using the Cremina and recently rebuilt a Micro Casa A Leva and find a huge difference in the shots. The Cremina giving thick shots with good mid and low notes and the Leva brings me more of the fruits and flowers cleanly with much less crema.