text: Good perry pears should have higher concentrations of tannins, acids, and other phenolic compounds. Some of the pears considered to produce consistently excellent perry include the 'Barland', 'Brandy', 'Thorn,' and 'Yellow Huffcap' cultivars. Compared to cider apples, perry pears have fewer volatile components and consequently fewer aromatics in the finished product. Their tannin profile is very different from that of cider apples, with a predominance of astringent over bitter flavours. They do, however, contain a high concentration of deca-2,4-dienoate, a group of esters that affords them their prominent pear aroma. Another important attribute of perry pears that distinguishes them from cider apples is their relatively higher content ratio of sorbitol to other sugars, such as fructose. Because sorbitol is not readily fermented by yeast, it is not converted to ethanol, so perry tends to have more residual sugar than cider produced from the fermentation of apples. In addition to producing a sweeter beverage, sorbitol also contributes to increased body and a softer mouthfeel in the finished perry. Compared to apples, pear pressing is made more difficult by the additional presence of specialized cells known as sclereids, which have thick cell walls that provide extra support and strength to the pear tissue. Because of this inherent perry pear attribute, the addition of enzymes and pressing aids is a commonly used practice for improving perry production.