Cherries are prized for their intense sweetness and bright color. A common question is whether these delicate stone fruits continue to sweeten after they have been picked. Understanding the answer requires looking into the horticultural science that governs how different types of fruit mature.
The Direct Answer: Non-Climacteric Fruit
The simple answer is that cherries do not get sweeter after they are picked. Cherries are non-climacteric fruit, meaning their ripening process effectively stops once they are detached from the parent tree. Unlike climacteric fruits, such as bananas or apples, which continue to mature off the plant, non-climacteric varieties must be harvested at peak ripeness.
The Science Behind the Sweetness Stop
The mechanism preventing post-harvest sweetening is tied to the cherry’s lack of a significant respiratory burst and minimal ethylene production after picking. Climacteric fruits utilize internal starch reserves, which enzymes break down into simple sugars during post-harvest ripening, leading to a noticeable increase in sweetness. Cherries do not accumulate sufficient starch reserves to power this conversion once removed from the tree.
Instead of a sugar increase, any perceived change in flavor is usually due to moisture loss and concentration. As a cherry loses water, existing sugars become more concentrated, creating the illusion of greater sweetness, but no new sugars are synthesized. Ethylene, which accelerates ripening in climacteric fruit, plays only a minor role in cherry maturation and does not trigger sugar development after harvest.
Maximizing Flavor: Indicators of Peak Ripeness
Since cherries cannot sweeten further after harvest, selecting fruit that reached its maximum flavor on the tree is the only way to guarantee a sweet experience. Peak ripeness for most sweet cherry varieties is indicated by a deep, uniform color, ranging from dark red to almost black mahogany. Lighter-colored cherries, such as Rainier, are ready when they develop a golden-yellow hue with a distinct pink or red blush.
A ripe cherry should feel firm and plump when gently handled, indicating high juiciness. The stem provides another helpful visual cue; fresh, bright green stems suggest the cherry was recently picked at its prime. Purchasing fruit with these attributes ensures the maximum sugar content, which fully developed while the cherry was still connected to the tree.
Preserving Quality: Post-Harvest Storage
Once cherries are picked, the focus shifts to minimizing quality degradation. Cherries are highly perishable due to their moderate respiration rate and susceptibility to water loss. To slow decay, cherries must be cooled quickly to a temperature between 30°F and 32°F (-1°C to 0°C) immediately after harvest.
Maintaining high relative humidity, ideally between 90% and 95%, is also necessary to prevent the fruit from shriveling. Cherries should only be washed right before they are eaten, as residual moisture accelerates decay and encourages mold growth. Keeping the stems attached also helps protect the skin and prolong shelf life in the refrigerator.