As previously described (Lermusieau et al. J. Am. Soc. Brew. Chem. 1999, 57, 29-33; Noël et al. J. Agric. Food Chem. 1999, 47, 4323-4326), the nonenal potential found in the wort before fermentation is a good indicator of beer staling. It derives from the retention of trans-2-nonenal by wort amino acids and proteins. The so-obtained adduct protects trans-2-nonenal from yeast reduction activity but can release it by acidic hydrolysis, mainly when the beer pH is low or the storage temperature inadequate. Although auto-oxidation in the boiling kettle revealed to be the limiting factor for staling, recent results clearly indicate that malt kilning is another significant source of nonenal potential. Of course, due to the presence of melanoidins, caramel malt (10%) brings a higher antioxidant activity to the wort. However, despite a low lipoxygenasic activity during mashing and a low auto-oxidation during boiling, this wort will be characterized by a higher nonenal potential. In the present work, different kilning temperatures will be compared in terms of malt reducing power and/or nonenal potential. The fate of trans-2-nonenal added just after germination will be also discussed.