One thing not yet mentioned is in what type of oak is tequila, and by extension Señor Rio, aged? Most tequila uses American oak from reconditioned bourbon barrels that have been planed down and recharred. Señor Rio takes a page from the playbook of aging used by Scotch whiskies and buys used barrels from another country.
For Señor Rio tequila, the quercus sessiliflora and quercus pedunculata barrels previously used to host cognac are used in the aging process. These oak types are especially complimentary to tequila because the rounded, buttery texture suits the almost angular structure of the isoamyl alcohol. Simply put…it smooths out the tequila. The barrels, of little use anymore for aging brandy, as the compounds imparted into the cognac happen mostly during the first 1-6 years. After that, it does not mean the cask is of no use. The chemicals, like lignin and cellulose are still useful for other spirits, and the reduced levels of vanillin and cinnamaldehyde mean that tequila can be aged in it without coming out tasting like an agave caramel.
Another benefit to using cognac barrels to age Señor Rio tequila is that the grain of the wood, although tight, is laced with sugar molecules left behind from the Cognac. These sugar molecules, esters, are small in number and enhance an already floral aspect of the tequila. It adds a little taste of honey that is especially noticeable in Señor Rio Reposado.
In Señor Rio Añejo, this hint of honey combines with the baking spice flavors that the cognac barrel still has. The Vanillin comes through and a hint of pepper is present in all of the Señor Rio expressions. What this means is that as the aging continues, the complexity of the flavors increases.
You may wonder why Tequila or Bourbon do not age as long as an XO (Extra Old) Cognac or some Scotches. The reason is that the temperature in Scotland is very cold and wet which means aging takes longer. In Cognac the smoothness can only be achieved from the quality of distillation and the laws of thermodynamics that state entropy always increases. The sharp rough molecules of alcohol smooth out over time. Any spirit will eventually smooth out, no matter how rough, if there’s a chance that alcohol molecules can evaporate. Señor Rio tequila doesn’t need to undergo this extra smoothing. It already tastes smooth and because it tastes so good, you won’t have it long enough for it to get any smoother!
I was shown a bottle of Scotch from the 1930’s that had never been opened and it had evaporated about 5-10%. Now this stuff is a tooth-dissolver when new. We tried it and it was very smooth, not complex. The alcohol level had dropped, and the ethanol alcohol base of the Scotch was markedly smoother. When people ask me if aging happens in the bottle, I say “No” with the caveat that time will smooth anything out. Have you ever noticed that you’ll sometimes see some droplets of condensation forming near the spout of a stoppered bottle? This is the alcohol trying to evaporate, and every spirit will see this happen.
I’ve likely bewildered you with how spirits, including Señor Rio, develop over time. Just be aware that a lot of love, care, thought, and time is in every bottle. What you’re tasting is the result of factors that have come to fruition in different countries and likely started decades or centuries before now. Señor Rio exists because a canal built by the Aztecs ensured there would be a steady ground water supply in Jalisco. And a 19th century Troncois forest squirrel dropped an acorn allowing it to stand out from the rest of the oak grove when it came time to harvest trees for barrels. Aging doesn’t just happen when the spirit hits the oak. It’s a series of events that ends with you pouring yourself some Añejo and enjoying the experience.