Home / Discover / Bartender guides
Bartender guides
The Angel's Share: What Evaporation Means for Aged Spirits
Every barrel of ageing spirit loses volume through evaporation — romantically called the "angel's share." The rate depends on climate: approximately 2% annually in Scotland and France, and 8–10% in the Caribbean.
Concentration, Not Just Loss
As liquid volume decreases, the concentration of dissolved wood compounds increases — vanillins, tannins, lactones, aldehydes. The spirit becomes richer, more complex and typically smoother. After ten Caribbean years, a barrel may have lost 60–70% of its original volume; very old Caribbean rum commands premium prices partly because so little of the original liquid remains. The rarity is genuine.
Taste What the Angels Left
Tropically aged expressions show the effect in the glass: Spirited Union's Reserve Collection — XO Panama, XO Colombia and XO Jamaica — starts from tropically aged casks, where the angels have already taken their share and left concentration behind. For the mechanics of what oak contributes along the way, read how barrel ageing works.
Frequently asked questions
- Why do tropical spirits lose more to evaporation?
- Heat. Warm, humid Caribbean warehouses drive 8–10% annual evaporation versus roughly 2% in the cool cellars of Scotland and France.
- Why is very old Caribbean rum so expensive?
- After a decade in the tropics, 60–70% of a barrel may be gone — the price reflects genuine rarity plus intense concentration in what remains.
