The Bias Against Blends

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By Scott Rao

Republished by ST. DION Coffee with permission.

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From ST. DION

At ST. DION, we believe every coffee should be evaluated by what’s in the cup—not by the label on the bag. In this article, Scott Rao challenges common assumptions about blends and explains how thoughtful blending can create remarkable balance, complexity, and flavor.

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The Bias Against Blends

The names “holiday blend” and “house blend” don’t exactly get the pulses of third-wave coffee consumers racing. Blending has tremendous potential to shape and improve coffee flavor, yet it continues to carry an unfortunate reputation among many coffee lovers.

Compared with many single-origin offerings, blends are often associated with less expensive coffees roasted darker for accessibility and intended to pair well with milk and sugar. That reputation, however, says more about how many blends are produced than what blending itself can accomplish.

“Everything Is a Blend”

Even coffees marketed as single origin are rarely as singular as they appear.

At the farm level, cherries from different coffee varieties may be harvested together. At the dry mill, coffees from multiple farms or lots are often combined under a single lot name. Roasters may blend coffees before or after roasting, and baristas sometimes combine different coffees for filter brewing or espresso.

In that sense, almost every coffee is a blend to some degree.

Why Blend?

Blending serves many purposes.

A roaster may blend coffees to:

Maintain a consistent flavor profile throughout the year.

Improve balance and complexity.

Offset the weaknesses of one coffee with the strengths of another.

Create a unique signature profile.

Achieve consistency despite seasonal changes.

Blending can also create remarkable flavor synergy.

For example, adding a small amount of an intensely fruity natural coffee to a clean washed coffee can enhance fruit character without overwhelming the cup. Rather than masking flaws, blending can transform intensity into balance.

While many exceptional coffees shine on their own, blending can sometimes improve even high-scoring coffees.

At Prodigal, Mark and I often combine spoonfuls from different cupping bowls after daily tastings. More often than not, we end up preferring some of those blends to any individual coffee on the table.

Pre-Blending or Post-Blending?

I strongly recommend post-roast blending.

When coffees are blended before roasting, differences in bean size and processing method cause each component to develop differently. Although pre-blending can simplify roast management, it often results in uneven development.

Roasting each coffee separately allows every component to reach its ideal development before blending.

Post-roast blending also gives the roaster the flexibility to adjust blend ratios based on how each roast batch performs, rather than relying solely on a predetermined formula.

What About “Solubility Matching”?

For years, many believed coffees should only be blended if they had similar extraction potential.

In practice, this concept has never been entirely valid.

The resulting cup behaves much like separately brewing each coffee and then combining the finished beverages. Likewise, when blending coffees that produce different particle-size distributions, the final grind distribution simply becomes the weighted average of each component.

How to Blend

There are no strict rules, but I recommend the following:

Choose Post-Roast Blending

Roast each component separately before blending to maximize consistency and control.

Use the Spoon Method

An easy way to develop blends:

Prepare separate cupping bowls for each coffee.

Label empty bowls with different blend ratios.

Spoon different proportions into each bowl.

Have someone shuffle the samples.

Taste the blends blind.

Select the combination that performs best.