Considerations—The Fermentation of High-Gravity Wort

Corn and barley syrups manufactured in different ways varied in fermentability. Tendencies observed with conventional or low-gravity worts were usually accentuated at starter solids of 18° P and greater. Carbohydrate composition appeared to be a factor inasmuch as decreased fermentability was observed when high-gravity wort glucose was in excess of 10% (of the total carbohydrate). Agitation and limited aeration in the early stage of fermentation each increased rate and degree of attenuation of wort containing a specific barley syrup. However, the combination of the two maximized the effect. High-gravity worts produced beers with normal ethyl acetate contents. While not tabulated, levels of higher alcohols were also normal. Examination of pitching rate suggested that about 1.4 × 107 cells ml of high-gravity wort gave best results.