Tomato Ripening Time

Stages of Ripening

• Tomatoes pass through a number of stages of maturity during the ripening process. Fruits start off green, varying from light to dark depending on the breed. Tomatoes are referred to as "breakers" when they display color changes from green to yellow, pink or red on 10 percent or less of the fruit surface. "Turning" tomatoes have yellow, red or pink color over 10 to 30 percent of their surface, and "pink" tomatoes have red coloring on 30 to 90 percent of the fruit surface. Ripe tomatoes display a deep, red color on 90 to 100 percent of their surface, and are ready for consumption at this stage.

Ripening Times

• The time it takes for tomatoes to ripen depends upon local conditions, as well as the stage of development at which the fruit is harvested. Most varieties of tomatoes attain their full size in 40 to 50 days after blossoming, and ripen in approximately 14 days. Mature green tomatoes take the longest to ripen: 18 days at 55 F. Light pink tomatoes can be ripened in 10 days at this temperature, and breaker tomatoes take 16 days. Time to ripening is dependent on temperature, and ripening times can be nearly halved if the temperature rises to 77 F.

Physical Process of Ripening

• Ripening begins in tomatoes when the fruit reaches its full, mature green size. When this occurs, the plant cuts off the flow of water to the fruit, and the chlorophyll, which gives the fruit its green color, begins to degrade. Pigmentation increases, accompanied by a drop in acidity and softening of the fruit, and the starches in the tomato turn into sugar. A hormone the plant produces, called ethylene, stimulates the ripening process.

Ripening Indoors

• Although some prefer to let tomatoes ripen fully on the vine, harvesting tomatoes early and storing them indoors can increase yield and fruit quality. Early harvesting can also help reduce damage from insect pests and birds. Tomatoes should be harvested when they reach their full mature green size and have just begun to show color. Picked tomatoes should be stored indoors at room temperature to ripen. Placing tomatoes in a brown paper bag can help speed up the ripening process by trapping ethylene gas produced by the fruit. Immature tomatoes should never be placed in the refrigerator, since this inhibits the ripening process. Ripe tomatoes can be canned or frozen for long-term storage