Vinegar production, 19th century cutaway artwork. This is a trickling method developed in 1823 by the German chemist Schutzenbach. The barrel is divided into three sections. An alcoholic solution in the top section trickles through an inert material packed in the middle section. Bacteria in the middle section produce acetic acid (vinegar) which is collected in the bottom section and removed via a tap. Air holes (bottom) and pipes (top) provide air and remove gases produced. Engraving from 'Grands Hommes et Grands Faits de l'Industrie' (Great Men and Great Facts of Industry), published in France circa 1880.