When ale became beer
Medieval English brewers made ale from malted barley and flavoured it, when they flavoured it at all, with herbs and spice mixtures called gruit. Ale did not keep for long. It was brewed in small batches and sold within days.
Hops changed that. The bitter flowers of the hop plant act as a preservative and give the drink a clean, dry taste, and brewers in the Low Countries and northern Germany had used them for centuries. Hopped beer came into England in the fifteenth century, brought by traders and by immigrant brewers from Flanders, and for a while the two names marked a real divide: ale was unhopped and beer was hopped.
Resistance and acceptance
The new drink met suspicion. Some people thought hops were a foreign weed that spoilt good ale, and a few towns tried to restrict their use. The argument faded as hopped beer proved cheaper to store and to ship, and as English farmers began to grow the crop. Hop gardens appeared in Kent in the early sixteenth century. In 1574 Reginald Scot published A Perfite Platforme of a Hoppe Garden, the first English book on growing hops.
By the seventeenth century the words had begun to merge. Today a pale ale is brewed with hops like any beer, and the old distinction survives only in the names.