TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The carbohydrate source is selected from at least one of paper, sludge from paper manufacture, fruit and vegetable waste, waste from the baking industry, seaweed and seaweed extracts, forestry derivatives, food crops, grain and crop residues, spent grains, chocolate, algae, non-edible crops and their residues and energy crops.    TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Components: The culture of butanol- and/or acetone-forming micro-organism comprises bacteria of the genus Clostridium.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The fermented product further comprises at least one compound selected from carbon dioxide and hydrogen.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The step of treating the substrate involves hydrolyzing the carbohydrate source in the presence of water and hydrogen ions, or water and hydroxide ions; hydrolyzing the carbohydrate source in the presence of an aqueous solution of sulfuric acid; and treating the carbohydrate source with at least one enzyme. Treating the substrate further involves diluting the substrate to provide a concentration of free copper ions of less than 20 mu M. The step of fermenting the treated substrate is carried out at a pH of greater than or equal to 5.1. The concentration of free copper ions in the fermentation step is less than 15 mu M. The fermentation step is carried out without the removal of solids from it. The treating and fermenting steps are carried out simultaneously or sequentially. The pot ale is provided by: adding yeast to wort comprising water and at least one carbohydrate selected from glucose and oligosaccharides of glucose; fermenting the wort to provide wash comprising water and at least one alcohol; and distilling the wash in a copper distillation vessel to provide a low wines distillate comprising at least one alcohol and a distillation residue of pot ale. The wort is provided by: grinding malted barley comprising starch to provide ground malted barley; mixing the ground malted barley with water to provide a mash comprising water and ground malted barley; hydrolyzing at least a part of the starch in the ground malted barley of the mash to provide draff comprising spent barley solids and wort comprising water and at least one carbohydrate selected from glucose and oligosaccharides of glucose; and separating the draff from the wort. The pot ale is the by-product of the manufacture of malt whisky (preferably Scotch malt whisky). Preferred Components: The fermented product further comprises at least one compound selected from ethanol, acetate and butyrate. EXAMPLE - White office paper and newspaper were shredded to 5 mm wide strips and 6.7 wt./vol.% was mixed with either water or 50% pot ale in 250 ml duran bottles and the pH adjusted to pH 5.5. After sterilization, the bottles were cooled and cellulase and Clostridium saccharoperbutylacetonicum (NCIMB 12606) were added. After fermentation, the acetone/butanol/ethanol (ABE) concentrations were determined. There was poor conversion of paper to ABE in water compared to pot ale, demonstrating that pot ale was required to provide additional nutrients. In pot ale, the ABE yields after fermentation with Clostridium saccharoperbutylacetonicum were 24.8 g ABE per 100 g office paper and 16.8 g ABE per 100 g newspaper.