The Wealth of Nations by Part 5 Chapter 2 Page 222

this composition, however, or for other reasons, it is not near so common to malt as to brew for private use.

It is difficult to imagine any equitable reason why those who either brew or distil for private use should not be subject to a composition of the same kind.

A greater revenue than what is at present drawn from all the heavy taxes upon malt, beer, and ale might be raised, it has frequently been said, by a much lighter tax upon malt, the opportunities of defrauding the revenue being much greater in a brewery than in a malt-house, and those who brew for private use being exempted from all duties or composition for duties, which is not the case with those who malt for private use.

In the porter brewery of London a quarter of malt is commonly brewed