Abstract During the last decade, observations on cider production sites allowed for some hypotheses to be made concerning relationships between “framboise” (cider-sickness) development and physical and chemical cider parameters as well as some process operations. Although Zymomonas mobilis has long been known to cause cider-sickness in British ciders, it had never been detected in France until recently from a number of “framboise” cases. The possibility to trigger “framboise” in cider by inoculation of the bacterium allowed for a better understanding of the factors leading to “framboise” development in ciders. The stage of the malo-lactic fermentation, amount of dissolved of oxygen, pH, combined effect of pH and sulfur dioxide and residual amount of utilizable yeast nitrogen (YAN) were studied. The main factor affecting cider sensitivity to “framboise” is the amount of YAN. If the amount of YAN is sufficient, the development of “framboise” will mainly be influenced by pH (sulfur dioxide playing a minor role).