Is there a general process/method to determine proportions for a blend of more than 2 coffees post roasts? I mostly roast SOs but like to play around with combinations usually a low acidity base and 2 others that have generally been known to work with at least 1 and usually 2 being a non-WP. Roast each to the trait I'm hoping to add and then the real challenge for me is proportions. Trying to zero in on something close as quick as possible during a first session then just tweaking it each day or adjusting to tastes(I keep the roasts separate). I try to have an SO of each usually as resting a day or so before I try to blend to get a feeling of what I have to work with. Then I'll start with what I've generally heard or make a wild zen guess. Then try to guess adjustments after I've pulled a couple shots. I can't take the time a commercial Roaster will put into perfecting a blend but would like to have a method to at least get close.

I used to blend about 40% first pops Brazil with 30% lighter roasted Sidamo or Yrg and 30% darker roasted Sumatra. I understand this to be a fairly standard recipe. It is roughly the blend used in barista competition for the last few years, and the Klatsch USBC and WBC blends have roughly this recipe.

Recently, I've been trying Kenya as the darker roast, and Guats as the lighter roast, with Brazil*, as always, in the middle. This yields a very different taste, not fruit and chocolate, but mulled spiced cider. Really hits the spot in the winter.

*Many of the latest blends we tried in the HB test left out the Brazil. Brazil is in straight espresso what milk is in a cappa, the creamy buffer and stabilizer. If the other coffees are just right, leaving it out can be a great move; but if the other coffees are too angular, IMO, you need the Brazil. In any case, its better to use Brazil than to bake an SO into flat submission.

I have a Brazil dp, Guat wp and Sidamo dp roasted and ready to blend up for the relatives visiting sat. I'll start with those recommendations which are about what I generally start with and about 70% of the time stay pretty close to. I end up getting requests for shots and milk drinks so try to make the blend bold enough to cut through milk and still work as a shot so I don't have to make adjustments.
I've been thinking the same thing in feeling I was really needing to crawl the heck out of some beans but can give a decent result sometimes. Roasting is complicated enough but blending seems to be the big mountain.

"Blending the rules" (Roast Magazine)

Interesting resource Dieter01 (Thomas).

Howard

Similar question and a little discussion is in this topic: Any advice on coffee blending?
The excellent 'Blending: the rules' was there too
Anyhow, I was asking more in terms of determining taste of two or three coffees blended together - something like blending coffees you already know how they taste on their own - and the papers posted speak more in terms of creating a blend. I can understand that in commercial environment creation of blend is the way of thinkning; now it looks like there is no other way for solving my question then experiment with just blending some known coffees on the spot.

And how about here, in Brazil, that we only can buy local green coffee? Tell me about finding nuances in coffee!

One good thing is that most of the coffee here is good for espresso even single. At least, easy to roast as single...

Márcio.

This may be more information than most people want to read - but I keep going back to Sweet Maria's discussion of blending. This is also mentioned in the other "blending advice" link above.