Tomatillos, a staple in Mexican cuisine, are often mistaken for green tomatoes due to their appearance and botanical relation within the nightshade family. These fruits are distinguished by the papery, lantern-like husk, or calyx, that completely encases them as they grow. A common question is whether these fruits continue to mature, or “ripen,” once they are removed from the plant. Understanding the unique post-harvest behavior of the tomatillo is key to maximizing its flavor and storage life.
Understanding Tomatillo Maturation After Picking
The question of whether tomatillos ripen off the vine has a nuanced answer depending on how one defines “ripening.” Unlike true climacteric fruits, such as bananas or avocados, tomatillos have a limited maturation process once picked. While they will not increase in size after harvest, they can undergo a noticeable color change if they were mature when picked. This change involves the fruit turning from bright green to a yellow or purple hue, depending on the variety.
This color shift is a sign of maturation, but it does not equate to the increase in sweetness and flavor complexity seen in a tomato ripening off the vine. Tomatillos produce low amounts of the ripening hormone ethylene during development. If they are left on the plant to become overripe, their ethylene production and respiration rates can increase significantly as they soften and turn yellow. For most culinary applications, such as salsa verde, the best flavor profile is achieved by harvesting the fruit when it is mature but still firm and green.
Signs of Optimal Harvest
Determining the optimal time to harvest a tomatillo relies on observing the papery husk rather than the fruit’s color. The fruit is ready to be picked when it has completely filled the husk, causing the calyx to feel tight and firm. This is often accompanied by the husk beginning to split open or tear slightly due to the pressure of the expanding fruit.
A ready-to-harvest tomatillo will cause the husk to become dry, changing its color from green to a tan or straw-like color. The fruit should detach easily from the plant with a gentle twist or tug, which indicates maturity. Harvesting at this stage ensures the fruit retains the characteristic tartness and firm texture desired for most recipes.
Maximizing Quality During Post-Harvest Storage
To maximize the quality and longevity of harvested tomatillos, the papery husk should be left intact, as it acts as a protective layer. Storing the fruit with the husk on helps prevent moisture loss and physical damage to the sticky skin underneath. Tomatillos are best stored in a cool, dry, and dark environment, such as a paper bag or an open basket, at temperatures between 41°F and 50°F.
The fruit can maintain its quality for two to four weeks under these conditions. Storing them at colder temperatures, such as below 41°F, can lead to chilling injury, causing pitting and spoilage. It is important to keep tomatillos away from high-ethylene-producing fruits like apples, bananas, and melons, as exposure accelerates softening and color change. While green tomatillos are preferred for tartness in sauces, those that mature to yellow or purple can be used for sweeter preparations.