Visit the Shut up about Barclay Perkins site

It's been a while since I mentioned Porter. At least a day or two. time to return to one of my favourite topics: Porter grists.

A method for obtaining the colour and flavour of Porter at the same time as using a grist mostly consisting of pale malt was eagerly sought. The pressure on costs caused by increased taxation during the Napoleonic Wars and the knowledge that pale malt was a cheaper way of getting extract than brown malt had prompted the change in Porter grists.

"Porter. A malt liquor of a deep brown colour and a peculiar flavour, which it derives from the malt used in brewing, it being highly dried in the malt-kilns. This, at least, was the composition of Porter until lately, when it has been found that the same colour and flavour may be communicated to liquor brewed from a mixture of brown and pale malt, by the addition of certain colouring matters, which being obtained from burning the same substance that causes the brown colour of the highly dried malt, produces a similar liquor it a far less expence of materials than when brown malt alone is used; because the pale malt yields a far greater proportion of saccharine matter than the brown, in which a share of the saccharum is burnt up in the kiln only for the purpose of producing a colour and flavour which may so easily be communicated to the beer of pale malt by a small quantity of burnt sugar."
“Pantologia: A new cyclopaedia Vol IX”, 1813, pages (doesn’t have page numbers)
For a while, when sugar was permitted for colouring, a sort of caramel was used. However the rules kept changing and sometimes brewers had to use concentrated wort instead.

"The colouring for porter is made by boiling coarse brown sugar in an iron pan with a small quantity of water, keeping it constantly stirred up; it is then set on fire and burned a few minutes, to give it the colour and flavour which might be obtained from brown malt. The fire is extinguished by putting on a cover. The residuum is now mixed up with water to the consistence of treacle, and makes the colouring, which is put to the beer while working in the square, and gives it the same colour and flavour it would have derived from being brewed from brown malt. Some brewers, to avoid the censures of the public, who restrain them to the use of malt and hops alone, concentrate a quantity of their best first wort, by boiling in the iron pan, and burn this instead of sugar, from which it does not materially differ.

A patent has been lately taken out by M. De Roche for colouring porter by the skins and husks of malt roasted to a coffee colour, and mixing them with the malt before mashing; or by infusing them in the water before brewing ; or by mixing them with the beer. This would undoubtedly give colour ; but we have some doubts of its communicating the flavour which is required."
“Pantologia: A new cyclopaedia Vol IX”, 1813, pages (doesn’t have page numbers)
Ultimately it was an improvement of De Roches roast husks, patent malt, which became the main Porter colourant.