Dow Breweries

The most cautionary story in Canadian brewing, and it took eight weeks. Dow was Quebec's dominant beer for most of two centuries when, in 1966, Quebec City hospitals began admitting middle-aged men — heavy daily drinkers, most of them Dow drinkers — with a heart failure nobody recognised. Twenty to twenty-five died. The suspected cause was cobalt sulphate, added by brewers of the era to hold a head on the beer; Dow was reported to have used far more than anyone else. Causation was never conclusively proven and not every victim drank Dow. It did not matter. Dow destroyed its entire Quebec City inventory to reassure the public, the public read the dumping as a confession, and the beer became la bière qui tue — the beer that kills. The medical literature still calls the condition Quebec beer-drinkers' cardiomyopathy. The cases stopped when brewers stopped using cobalt. The brand never came back.

1. 1790
   Founded at La Prairie

   Thomas Dunn, a young Scottish brewer, sets up south of Montréal — not at Quebec City.

2. 1808
   Moves to Montréal

   Dunn relocates the enterprise and acquires brewery lands on Notre-Dame Street.

3. 1829
   Dunn, Dow & Co.

   William Dow, foreman since about 1818, is a partner by November 1829, joined by his brother Andrew.

4. 1834
   Dunn dies; the Dow name

   DCB dates William Dow and Company to 1834, the year of Dunn's death; the Quebec heritage register dates the name to 1841. Both are recorded.

5. 1864
   Dow sells, name stays

   Sold for £77,877 to associates headed by Gilbert Scott. It kept his name.

6. 1909
   National Breweries

   The enterprise joins National Breweries.

7. 1952
   Dow Brewery Limited

   National Breweries, under Canadian Breweries Ltd., becomes Dow Brewery Limited.

8. 1966
   The Quebec City cases

   Cobalt cardiomyopathy among heavy drinkers collapses the brand.

9. 1997
   Brands discontinued

   The Dow name leaves the market.

Sources

1. peopleDisputed

   Founded in 1790 at La Prairie by Thomas Dunn, a brewer, who moved the enterprise to Montréal in 1808. William Dow was a partner by November 1829 and the firm took his name after Dunn's death. THE DATE OF THE NAME CHANGE IS DISPUTED: the Dictionary of Canadian Biography gives 1834, the year Dunn died; the Quebec cultural-heritage register gives 1841. Both are recorded and neither is chosen. This replaces an earlier statement of this archive's that asserted 1841 alone, and an older record naming a "Thomas Dow" who never existed.

   DOW, WILLIAM — Dictionary of Canadian Biography, vol. 9 · University of Toronto / Université Laval · 2026

   ScholarlyHigh reliabilityAccessed 2026-08-19Reviewed 2026-08-19
2. cityConfirmed

   Dow was not founded at Quebec City. Two different men named Thomas Dunn have been conflated: the brewer who founded at La Prairie in 1790 and moved to Montréal in 1808, and Thomas Dunn (1729-1818), politician and administrator of Lower Canada, who owned the Cape Diamond Brewery at Quebec City among many ventures and was not a brewer. Quebec City was Dow's largest market and the site of the 1966 cases; it was never its home.

   Thomas Dunn (lieutenant-governor) · Wikipedia (English) · 2026

   ReferenceMedium reliabilityAccessed 2026-08-19Reviewed 2026-08-19

Only the claims above are sourced. Everything else on this page is the archive's own research and has not yet been tied to a document — which is worth knowing rather than hiding.