J.C. Jacobsen's letters to his son reveal a wealth of technical brewing details

I’ve been digging into Carlsberg history again – more specifically the letters from J.C. Jacobsen to his son Carl. As a young man Carl was packed off to travel the breweries of Europe for four years as part of his apprenticeship in brewing. The letters published in Danish as Din hengivne Jacobsen (Your devoted Jacobsen) are a fascinating insight into not only the characters of J.C. and Carl, but also into the techniques and practices of brewing at the time (1866-1870).

On his sojourn, Carl gained access to some of the greatest breweries of the time – both on the continent and Great Britain. Zum Spaten, Weihen Stephan, William Younger, Allsopp, Bass, Ushers, Evershed, Barclay Perkins, Lovibonds, Truman and Whitbread all figure in the letters of the father to the son. Carl actually worked for some time in Wm. Youngers and Eversheds  Allsopp’sand had several interviews while in Burton with the noted brewing chemist Horace Brown

The letters illustrate Jacobsen’s thirst for brewing knowledge as he fires off letter after letter with questions about malting, mashing temperature, the cost and construction of pumps and corrugated iron, bottling and especially how English ales were brewed – Porter and Pale Ale in particular. His goal was to open a brewery for English-style beers to get a slice of the lucrative export market.

Some of his last letters in 1870 are with a desperate need for detail before Carl leaves Great Britain to return home:

Have you in Burton received reliable information about the degree of attenuation for Export Ale and Pale Ale in the larger breweries during the main fermentation and at the filling of casks? It is not necessary for me to call attention to how important it is to know the measurements one should achieve during fermentation.

Despite this demand for information about the brewing techniques used in Great Britain he never really got over his dislike of the taste of the beer. He writes about Bass:

Most of the beer types from Bass have, to my taste, far too much dry hopping. In some of the casks there was an unreasonable amount of hops. Is this necessary for its keeping abilities or is it only a matter of taste?

When Carl returned to Denmark he did in fact open a brewery for English styles, but was never convinced that it would take off at home. He preferred to export lager beer, which he considered excellent, despite his father’s worries that it wouldn’t travel well and damage his hard-won reputation.