Fast Limoncello

We've made a lot of liqueurs and infusions over the years, and limoncello was the one that got us started. For the most part, we've always used one of the more traditional methods, wherein the zest of the lemons is steeped in alcohol for at least 10 days, then strained and sweetened. ​​

However, there are some tricks to extract more flavor and to complete the liqueur in less time—as in hours. 

The act of steeping the peels in vodka works because vodka is basically just water and alcohol, both of which are solvents for the flavor compounds in the rind. Most of the flavor is in the aromatic oils in the zest, which would be dissolved by the alcohol. To speed things along, you can use a method to extract the oils more quickly and make them more available.

This involves muddling the rinds with sugar. Through osmosis, the granules of the sugar break down the cellular structure of the rinds, releasing the oils. This is called oleo saccharum, or "oily sugar," and it's a common tactic among bartenders to get a more potent citrus flavor. We learned this technique from "Shrubs: An Old-Fashioned Drink for Modern Times" by Michael Dietsch.

The other thing that speeds the process along is elevating the temperature of the solution. By packing the liqueur in a vacuum-sealed bag and immersing it in a heated bath in a method called sous vide, you are allowing the compounds to dissolve more rapidly.

Because the bag is sealed, you retain all the aromatic compounds and alcoholic content of the liqueur. Using this recipe, you can create a limoncello in just three hours, as opposed to the traditional method, which takes 10 days or longer. 

If you do not have a sous vide immersion circulator, you can simply complete this recipe by steeping as you would the traditional recipe. It will take longer than two hours, but likely less than 10 days. It should be ready as soon as the sugar is dissolved.