Beer history · English
John Richardson
Applied the hydrometer to wort and published the tables that made it useful — which showed brewers that brown malt was poor value and changed porter.
Credited with
Inventing the hydrometer.
What the record supports
Applied an existing instrument to a new problem, which is a different and in this case more valuable act. Hydrometers long predate him. Richardson published *Statical Estimates of the Materials of Brewing* in 1784, which set out how to use one on wort — he called the result a saccharometer — and, crucially, supplied the tables that turned a reading into a decision. Without the tables the number means nothing; with them a brewer can compare malts, detect losses and cost a recipe.
Why it matters
Made brewing measurable in the one dimension that costs money. The immediate consequence was that brown malt was shown to yield far less extract than pale, and British porter was reformulated around that finding within a generation.
The tables are the contribution, and they are the part nobody remembers. An instrument that produces a number is a curiosity; an instrument plus a reference that tells you what the number is worth is a management tool.
The technology
Connected
Styles: English porter
Places: London
Last reviewed 2026-08-29.