The 1830 Beer Act was very specific as to what would happen to anyone selling watered or adulterated beer.
". . . and if any person so licensed as aforesaid shall knowingly sell any beer, ale, or porter made otherwise than from malt and hops, or shall mix or cause to be mixed any drugs or other pernicious ingredients with any beer sold in his house or premises, or shall fraudulently dilute or in any way adulterate any such beer, such offender shall for the first offence forfeit any sum not less than ten pounds nor more than twenty pounds, as the justices before whom such offender shall be convicted of such offence shall adjudge ; and for the second such offence such offender shall be adjudged to be disqualified from selling beer, ale, or porter by retail for the term of two years, or to forfeit any sum of money not less than twenty pounds nor more than fifty pounds, at the discretion of the justices before whom such offender shall be adjudged guilty of such second offence ; and if any offender convicted of such offence as last aforesaid shall during such term of two years sell any beer, ale, or porter by retail, either in the house and premises mentioned in the licence of such offender, or in any other place, he shall forfeit any sum not less twenty-five pounds nor more than fifty pounds, and shall be subject to a like penalty at any and every house or place where he shall commit such offence ; and if any person shall at any time, during any term in which it shall not be lawful for beer to be sold by retail on the premises of any offender, sell any beer by retail on such premises, knowing that it was not lawful to be sold, such offender shall forfeit any sum not less than ten pounds nor more than twenty pounds, as the convicting justices shall adjudge."To put the minimum 10 quid fine into context, remember that a pint of beer only cost 3d to 4d at the annual rent of a beerhouse was just 2 pounds. Ten pounds was a substantial sum. Anyone caught twice, risked losing his licence for two years. Yet despite these harsh punishments, adulteration was still rife. There must have been an awful lot of money in it.
"A collection of statutes connected with the general administration of the law", 1836, pages 910-911