Cherry tomatoes are climacteric fruits, meaning they continue ripening even after being separated from the vine. This post-harvest change is driven by the production of the gaseous plant hormone, ethylene, which triggers color, flavor, and texture alterations. Understanding this natural mechanism allows for successful indoor ripening, which is useful when cold weather threatens the end of the growing season.
Preparation Before Ripening
After picking, prepare the tomatoes to ensure a successful ripening environment and prevent decay. Gently wipe the exterior of the fruit with a dry cloth to remove surface dirt or debris. Avoid washing them, as excess moisture encourages mold growth. Sorting the harvest is important; separate fully green tomatoes from those showing a slight blush of color.
Discard or set aside for immediate use any fruit showing signs of damage, such as cracks, insect bites, or soft spots. These injured areas can quickly introduce spoilage organisms to the entire batch. If the small, pointed stems are still attached, carefully remove them. Sharp stems can puncture neighboring tomatoes, creating entry points for bacteria and fungi that halt ripening.
Creating the Ideal Ripening Environment
Ripening relies on creating a confined space that allows the fruit’s naturally produced ethylene gas to accumulate. Place the sorted tomatoes in a paper bag, cardboard box, or shallow container. These materials offer slight breathability while containing the gas. Arrange the tomatoes in a single layer to prevent bruising and ensure air circulation.
The accumulated ethylene accelerates color development and softening. The ideal temperature range is between 60°F and 75°F. Temperatures above 86°F inhibit the production of lycopene and carotene, the pigments responsible for the red color. Store the container in a dark or indirectly lit location, as light is not necessary for ripening and direct sun causes overheating. Check progress daily, removing any fully ripened or decaying tomatoes to protect the rest of the batch.
Accelerating Ripening with Ethylene
The ripening process can be sped up by introducing an external source of ethylene gas into the container. Place a high-ethylene-producing fruit, such as a ripe banana, apple, or avocado, alongside the tomatoes. The added fruit increases the gas concentration, hastening the onset of ripening.
While effective for speed, rapidly ripened fruit may not develop the same depth of flavor compounds as those ripened slowly on the vine. Check the accelerator fruit daily, as its high ethylene production means it will spoil quickly. Promptly removing the external fruit prevents the buildup of excessive moisture or mold that could damage the cherry tomatoes.
Post-Ripening Storage
Once the tomatoes achieve their desired color and firmness, remove them from the ripening container and store them correctly. Fully ripe tomatoes should be kept at room temperature, ideally between 60°F and 70°F. Never refrigerate them, as storing tomatoes below 50°F damages cell membranes. This results in a mealy texture and reduces the aromatic compounds that define their flavor.
For the best taste, consume ripe cherry tomatoes within three to five days of reaching peak color and texture. Although refrigeration extends shelf life, it is generally avoided due to the adverse effect on flavor and texture. Store them in a single layer on a counter or shallow basket, out of direct sunlight, to maintain quality.