The present invention is directed to novel methods to produce carbohydrate polymers and oligomers especially for pharmaceutical and food industries. The invention is directed to methods to remodel monosaccharides, and/or oligosaccharides and/or polysaccharides by a different monosaccharide, oligosaccharide or polysaccharide and optionally by further alcohol substances, under condensing conditions, preferably in acid catalysed reactions.