AbstractDry bulb onion (cv. Rijnsburger and Giant Zittau) were stored from September 1973 to late May 1974 at 2, 25°C and ambient temperature (mean 6°C). Flavour changes were monitored at intervals on freeze‐dried samples by determination of (a) pyruvate, (b) lachrymator (thiopropanalS‐oxide) and (c) g.l.c.‐headspace total peak areas. Flavour intensity increased progressively with length of storage to about 190 days and was usually followed by a steep downturn to 240 days' storage. These changes have been interpreted in terms of incidence of sprouting and changes of respiratio