Those who like their cheddar cheese really sharp may be surprised to learn it wasn’t supposed to be that way.

In the 1930s the finest cheddar was mellow, rich, nutty and buttery. Sharp cheddar was definitely frowned upon.

Such was the information imparted by Bronwen and Francis Percival, authors of Reinventing the Wheel — Milk, Microbes, and the Fight for Real Cheese, when they visited the Wilton Historical Society on Sept. 8. The Percivals, who are husband and wife, made the historical society their third stop on a national book tour. Their talk was followed by a tasting of artisanal cheeses provided by the Fairfield Cheese Company.

The Percivals explained that in the late 19th Century, English farmers exported cheese and butter but not ‘drinking milk’ because there was little call for it. As a result, farmhouse cheeses — those made on a farm — became known for their individual tastes due to the microbes in the cheese that were very regionally specific.

The advent of pasteurized milk changed all that. Milk needs to sour to make cheese but pasteurized milk will never sour. Starter cultures were developed to enable pasteurized milk to be used, but that made the flavors of cheese more homogenous.

“Different microbes add different flavors,” the Percivals said. Starter cultures were uniform.

Pasteurization and the use of starters also brought along industrial cheese making, as did the breeding of cows that produce more and more milk, making it difficult for farmers to compete.

“The last farmhouse Stilton was produced in 1935,” Francis Percival said. In Normandy, there are only two farmhouses making traditional Camembert de Normandie.

Happily, there is a resurgence of artisan cheesemakers seeking out production methods of earlier generations.

Reinventing the Wheel, published by the University of California Press, covers these issues as well as today’s markets and the challenges faced by small-scale cheesemakers. There is also an appendix on how to buy cheese.