Wine blending exercises often evoke images of swirling wine glasses and discussions of nuanced aromas. The reality is a bit different. In commercial production blending, many blends must be made from a finite volume of components, and no one blend can be sacrificed for the quality of the others. In other words, allocating one wine component has ripple effects for every other blend you need to make. Therefore making blends one at a time is rather difficult. I've found making every blend at once is much easier, and Excel to be indispensable. The other issue in commercial blending is the need to use every wine component and not have leftovers. Large wineries can consolidate homeless wine components (if you've ever wondered why Petite Sirah would be blended with Merlot this is it) and high-end wineries can simply demote leftover lots to a second label or sell it as bulk wine. With this client however, production volumes are small and the wine components are all good so there is no need or desire to not use every bit of in the blends.
I find conceptualizing wine blending to be fun as a thought exercise, but difficult in execution. A visual depiction of how to allocate components makes the process much more straightforward. In the example below, I came up with a blend scenario that looks good on paper and three other candidates to allow for adjustments. After tasting the the lab blends (single bottle trial blends) the owners and I came up with our favorite blend candidates. It would be a rather incredible stroke of luck if all the blend candidates we chose all came from the same blending scheme (it didn't). The blend for one wine wouldn't allow for the blend of another. Ultimately the solution was to sacrifice the quantity (but not the blend percentages) of one wine and to make a very minor percentage adjustment on another wine. By any account, a win-win situation. This would have been an impossible task if we just sat down and starting tasting wine components without a first step on paper.