By Amy LaHue, Oak Solutions Specialist with guest contributor Andrew Wiehebrink, R&D Spirits Division

Distillers have mastered their craft, but even the most refined spirit can sometimes fall short of the rich color they envisioned. When that happens, I am here to work alongside them to determine the best path forward.

During a recent collaboration, we explored one of the most natural methods for enhancing color— exposure to new oak.  This process imparts color primarily through two key factors: toast profile and tannin content. But I began to wonder which of these has the greater impact?

There are many things to consider.  For instance, French oak contains roughly ten times more tannin than American oak. It’s only natural to assume a dark-toast French oak would be ideal, as it offers the best of both worlds— high tannin content and a deep toast profile. But there’s a catch… toasting degrades tannins, especially in French oak. Knowing that raised new questions. Would untoasted French oak impart more color than a heavily toasted one? And could a dark-toast on American oak achieve similar results?

We can’t answer those questions without giving consideration to proof. Lower-proof spirits, with more water content, tend to draw out tannins. While higher-proof spirits extract more compounds from the toasted wood, which contribute to color in a different way.

With so many variables at play, it was time to tap into the expertise of our R&D Spirits Division. It was then that Andrew Wiehebrink brought forth a controlled experiment designed to give us the clear answers we were looking for.

The Experiment

To analyze color extraction, 6g/L of oak chips (American oak, French oak, and various toast levels) were soaked in vodka at two different proofs—80 and 120—for four weeks. The goal: to determine whether tannins (which have an affinity for water) or toast-derived compounds (which interact more with alcohol) played a bigger role in color development.

The Results: Proof and Toast Matter

The findings revealed that both proof and toast level significantly influence color extraction, especially with French oak:

• At 80 proof: Lighter-toast French oak chips extracted more color compared to higher proof— likely because the tannins remained more intact.
• At 120 proof: Darker-toast levels extracted more color, as the alcohol dissolved more toast-derived compounds.
• The darkest overall extraction came from our NG.466 French oak chip, which features a medium-to-bold toast (not even the darkest toast in our lineup).
• The lightest extraction, across both proofs, was from untoasted American oak.

A higher proof did extract more color from darker toasts, making American oak NG.455 a viable and cost-effective option for color enhancement.

Key Takeaways for Distillers

If you’re looking to boost color naturally, French oak with a medium-plus to bold toast profile consistently delivers strong results across both proof levels. The data supports several observations:

• Lower-proof spirits exposed to untoasted French oak will extract more color than higher proof spirits due to the elevated tannin concentration and tannins being more water soluble. That said, toasted French oak typically imparts even more color overall.
• Higher-proof spirits pull more color from dark-toasted woods, including select American oak options.
• Some American oak products offer satisfactory results, especially when cost is a factor.
• For consistent and rich color extraction, bold or heavy toast French oak remains the safest and most effective option. 

Oak Solutions Group, a subsidiary of Independent Stave Company, is a premium oak products company that is focused on providing expert advice and unparalleled selection. We share our sensory science and our creative technology to help the world's best distillers achieve their visions.

Have questions or want to explore oak alternatives for your spirit? Email Amy today.