This is a simple point but one I didn’t know before. Often you’ll see that scotch and other whiskies are aged in Spanish oak barrels that previously held sherry. However, I’ve always been told the barrels in the sherry soleras are American oak. What gives?
Thanks to Billy Leighton, Head Blender at Midleton Distillery, I have an answer. He says that yes, the true barrels on the sherry soleras are American oak and as old as possible. They do not want wood influence in sherry so the barrels don’t lend any flavor.
Traditionally, sherry was shipped to the UK in barrels (rather than bottles), and for that they would use the much less expensive/lower quality (at least at the time; I can’t speak for that now) Spanish oak casks, rather than American oak ones.
After being emptied, those casks would have been the ones reused to age scotch and other whiskies.
The Redbreast Lustau Edition is aged in ex-bourbon American oak barrels and sherry conditioned Spanish oak casks.