The present invention relates to a thermosetting binder composition containing water and a water-soluble oligomeric ester of at least one saccharide chosen from reducing sugars, non-reducing sugars and hydrogenated sugars, the hydrogenated sugars being chosen from the group consisting of erythritol, arabitol, xylitol, sorbitol, mannitol, iditol, maltitol, isomaltitol, lactitol, cellobitol, palatinitol, maltotritol and hydrogenation products of hydrolyzates of starch or of lignocellulose materials, and of at least one polycarboxylic acid, the binder composition having a dry matter content of between 50% and 80% by weight, the water-soluble oligomeric ester representing at least 80% by weight, preferably at least 90% by weight, of the cry matter content of the thermosetting binder composition, and the thermosetting binder composition containing less than 10% by weight, preferably less than 5% by weight, with respect to its dry matter content, of free sorbitol.
It also relates to the use of such a binder composition for the manufacture of a product based on mineral or organic fibers which are bonded by an insoluble organic binder.