Avoid Advance Prep for Garlic

By Cook's Illustrated Published January 2009

We’re always looking for ways to make our kitchen work more efficient and will often prep recipes a day in advance if we know we’re going to be busy. But noticing that garlic can develop a particularly strong odor if minced too far in advance, we decided to run a quick test. We used garlic in three different applications: lightly cooked in Spaghetti with Garlic and Olive Oil, raw in a garlicky Aïoli, and as a more subtle flavoring in our Best Caesar Salad. For each recipe, we used freshly minced garlic, garlic that had been minced 6 hours in advance, and garlic that had been minced the day before. Both the 6-hour- and 1-day-old minced garlic were so powerful, they overwhelmed the other flavors in the dish.

Turns out, garlic flavor comes from a compound called allicin, which is not formed until after the garlic’s cells are ruptured. As soon as you cut into garlic, the allicin will start to build and build until its flavor becomes overwhelmingly strong. So if you’re going to prep a recipe in advance, make sure to leave the garlic cloves whole until the last minute.


Garlic minced too early can develop an overly powerful flavor and aroma. Keep your cloves whole until just before using.