bletting

Bletting is a post-harvest ripening process in which certain fruits are deliberately allowed to soften and become edible after partial deterioration. The process relies on enzymatic breakdown of the fruit’s tissues, often aided by naturally occurring microorganisms, to convert hard, inedible fruit into a palatable state. It is most closely associated with the medlar (Mespilus germanica) and the sloe (Prunus spinosa).

In practice, bletting involves leaving the fruit in storage or in a cool, humid environment for a period that can range from weeks to months. Medlars are typically picked firm and allowed to blett until the flesh softens and develops a honeyed, complex flavor. Sloes, after exposure to frost or extended storage, lose much of their astringency and become suitable for culinary use, especially in liqueurs such as sloe gin.

Process details vary by species and conditions, but the pace and outcome depend on temperature, humidity, and time, as well as the activity of surface yeasts and molds that contribute to flavor development. Bletting distinguishes edible fruit obtained through controlled deterioration from ordinary spoilage, though unsafe mold growth or off-odors indicate spoilage rather than desirable bletting.

Historically, bletting provided a means to consume fruits that were otherwise inedible at harvest, and it remains a reference point in discussions of traditional post-harvest fruit preparation and fermentation. See also ripening and post-harvest handling of fruit.