"James S. goes on to point out that while you can achieve the percentages suggested by Craig using modern barley, malting techniques, yeast, and equipment, such

"James S. goes on to point out that while you can achieve the percentages suggested by Craig using modern barley, malting techniques, yeast, and equipment, such ‘show-stopping’ figures were unlikely to have been achieved by even the commercial producers of the sixteenth and seventeenth centuries." This is a key point. Malting is tricky: The barley seed must be germinated, since the enzyme that converts starch to fermentable sugars is produced by the sprouting seed. Then the germinated seed must be sterilized in a way that prevents too much of the starch from being converted but also does little damage to the grain. This can be done with drying, toasting, and smoking, but it requires a lot of process control to get a uniformly "pale" malt rather than a darker caramel or chocolate malt where some of the starches and sugars have been caramelized. The development and popularization of pilseners and other light, clear beers in the 19th century was driven by techical advances in malting. 18th century malts were certainly less advanced, more uneven in quality, with a higher proportion of caramelized and toasted sugars and consequently a lot of body and a lower alcohol content.