Temperate fruits may be classed into two groups on the basis of their texture. One group comprises fruits that soften greatly as they ripen. These are characterized by a soft melting texture and usually have a relatively short shelf life. The measurement of the texture of these fruits is relatively straightforward. The second group encompasses fruits that soften moderately as they ripen. These are characterized by a firm, crisp, fracturable texture and have a relatively long storage life. The measurement of their texture poses a number of complex problems. Some factors that affect the firmness of temperate fruits are the kind, size, variety, maturity and temperature of the fruit, and cultural factors.