Content of polyphenols in cider apples is of utmost importance; while procyanidins are the only true tannins, other phenolic compounds can act as precursors for cider aroma (Lea, 1995; Wojdylo, 2008). Moreover, human health effects have been indicated for some phenolic compounds in apple like phloridzin (Schulze et al., 2014). A thorough screening of the chemical contents of cider apple cultivars could therefore be used as a basis for developing more healthy beverages. A suitable level of acidity is required to obtain sufficient flavour and to avoid bacterial infection during the fermentation. To ensure sufficient fermentation, a comparatively high sugar content is also desirable. Most craft ciders are produced from a careful blend of cider and dessert cultivars, which together offer the desired levels of tannins, acid and sugar. Chemical content in dessert apple is affected by various environmental factors like orchard location and management (Tahir and Nybom, 2013). A similar environmental impact is expected for cider apples. In a recent trial with four English cider cultivars in Washington, USA, chemical content was compared to data obtained for the same cultivars when previously grown at Long Ashton in England (Alexander et al., 2016). Amount of tannins in the Washington-produced juice was almost halved compared to that in England, possibly due to differences in, e.g., rootstock, pruning, irrigation and fertilization. In addition, significant year-by-year variation in the Washington orchards could be attributed to weather conditions. Part of the fruit yield is usually lost during harvest and storage due to fungal diseases like blue mould, Penicillium expansum (Pianzzola et al., 2004). Commonly, harvesting in cider apple orchards consists of allowing the fruit to drop to the ground-sometimes after vigorous shaking of the trees. This procedure results in numerous potential entry points German Society for Horticultural Science Summary Craft apple cider is obtained by fermentation of juice from tannin-rich cider apple cultivars. Polyphenols in cider apples are very important; while procyanidins are the only true tannins, other phenolic compounds can act as precursors for cider aroma. Several recent studies have also reported that a high content of polyphenols in apple decreases susceptibility to the common storage rot blue mould caused by Penicillium expansum. Chemical content was determined in fruit of 19 Swedish-grown cider apple cultivars and 5 dessert apple cultivars in 2016. Inoculation with blue mould spores was undertaken in 2016 on 5 cider apple cultivars and 5 dessert apple cultivars, and repeated again in 2017 on 8 of these cultivars. Contrary to expectations, the cider apple cultivars were significantly more susceptible to blue mould in spite of their higher phenolics content. Although apparently unrelated to amount of phenols in the fruit of our study cultivars, heritability of blue mould susceptibility should be further investigated since all of the cider apples had one parent in common: 'James Griev...

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