behind the science
how aging works
Aging is more than just time in a barrel. It’s a complex chemical dance between spirit, wood, and the environment.
Did you know that:
Temperature fluctuations impact how deeply the spirit penetrates the wood?
Ethanol and water evaporate differently, influencing alcohol concentration?
Barrel composition affects flavor extraction, color, and pH balance?
Understanding these factors allows distillers to refine their aging process — and that’s exactly what the DistillAge3D model does.
TURN DATA INTO FLAVOR
Our proprietary model takes the guesswork out of barrel aging by simulating key aging parameters:
Barrel temperature — tracks internal temperature changes and their effects
Angel’s Share prediction — calculates evaporation rates of ethanol and water
Wood interaction — simulates how different barrels (size, char level, type) affect maturation
Color and chemistry — monitors pH shifts, congener evolution, and flavor profile changes
Case study: Exploring the Impact of Entry Proof on Spirits Maturation with Scotch Whisky
Proof gallons are a cornerstone of the spirits industry, so enhancing our 3-D barrel maturation model to account for entry proof was a logical next step. By delving into the literature, we uncovered a fascinating dataset on Scotch whisky maturation in uncharred American white oak barrels, featuring sinapaldehyde and syringic acid concentrations.
Key Studies
• Clyne et al. (1993): Found that lower ethanol concentrations were less effective at extracting sinapaldehyde.
• Withers et al. (1995): Suggested that oxygen content in the barrel significantly impacts syringaldehyde and syringic acid, though entry proof had no statistically significant impact.
• Literature review (Haeseler & Misselhorn (1958) discussed in Singleton and Draper (1961), to Burtron-Benitez et al. (2023)): Revealed conflicting findings on the role of entry proof in the development of wood-derived compounds.
Integrating Chemistry into the Model
To investigate further, we expanded the model to include a chemical mechanism that simulates the transformation of wood lignin with ethanol, followed by oxidation reactions leading to syringic acid. We also incorporated the influx of oxygen into the barrel over time, a critical factor identified in the studies.
Simulating History
Using historical weather data from New Keith, Scotland, around the time of the Clyne and Withers experiments, we optimized a single set of reaction constants and ran the model under two different entry proof levels and barrel sizes, as seen in the figure to the right.
Findings
• Sinapaldehyde: Slightly higher at the higher entry proof, aligning with Clyne’s findings.
• ABV Results: Minimal differences observed between the two entry proof levels.
• Oxygen’s Role: Reinforces the importance of oxygen content in influencing syringaldehyde and syringic acid concentrations, as noted by Withers et al.
What’s Next?
While these initial results reflect both Clyne’s and Withers’s findings for uncharred barrels, more experimental data (with error bars!) are needed to fully understand how initial proof impacts the extraction and formation of key compounds during maturation.
This study highlights how advanced modeling can shed light on the intricate interplay between chemistry, barrel design, and environmental factors in spirits production.
Figure 1. Predictions of (top) sinapaldehyde and (bottom) syringic acid for American Standard Barrels and miniature barrels based on different proofs.