Reading a Regauge: OLA, RLA and What They Tell You
A cask of whisky is not a fixed quantity. It breathes. Every year a little spirit evaporates through the wood, the strength shifts, and what remains is slightly different from what went in. A regauge is the measurement that tells you exactly where a cask stands today. Learning to read one is the difference between buying a cask and buying it well.
The three figures that matter
A regauge gives you three numbers. Original litres of alcohol, or OLA, is the pure alcohol first filled into the cask. Regauged litres of alcohol, or RLA, is what remains now. Strength, expressed as ABV, tells you how the spirit has concentrated or softened over time. Read together, they describe both how much whisky you own and how it has matured.
Why the loss is not only loss
The gap between OLA and RLA is the angels' share, the spirit lost to evaporation. It sounds like a cost, and in volume it is. But that same evaporation is what concentrates flavour and lifts a young spirit toward something rare. A cask that has given up volume has often gained character. The figure to watch is not only how much has gone, but how the strength is holding: a cask drifting toward the minimum strength for Scotch has a different future to one sitting comfortably above it.
What it means for value
Because bulk cask value is usually expressed per litre of pure alcohol, the RLA is the number a trade buyer prices against. A cask sold on its original fill volume, years after filling, is not being priced on what is actually there. We quote against the current gauge, not the fill, and we share the full gauging record on every parcel we supply, so you are pricing what you own rather than what it once was.
Read before you buy
A regauge is a small document that answers most of the questions worth asking: how much, how strong, and how well it has aged. We would always rather you read it than take our word for it.
Cask whisky is unregulated and illiquid; value can fall as well as rise, and past performance is not a guide to future results. Nothing here is financial advice. But a cask is one of the few assets that will tell you exactly what it is, if you know how to read the gauge.