I'd already found a couple of references in "The report of the departmental committee on beer materials". But they were too vague, only implying it was prepared from some type of grain.
Frank Thatcher's book was the suggestion that answered pretty much all my questions. It's a book I already had, both physically and digitally. A bit embarrassing, really. I've been using Thatcher as a source in my current book project. Specifically the part on beer ingredients. In my defence, I haven't got to adjuncts yet.
Beanes' Patent Grist is mentioned many times. There are even descriptions of how it was produced and how it was used.
"In the previous chapter on malting I have thoroughly explained the manufacture of malt and what a good sample of malt should resemble. It will now be necessary to define the other materials employed by brewers. These consist of amber, chocolate or brown , crystal and black malts, hops, various types of sugar such as invert, glucose, dextrin-maltose, and other types of such sugars including caramelized malt extract, maltodextrins, etc .; also raw cane sugar, caramels — those suitable for colouring purposes only, and those which possess a characteristic flavour for giving black beers features entirely of their own. We have also employed in convertors, raw grain , such as barley, oats , rice, maize, rye, wheat and sago ; and specially prepared grain , which includes flaked maize and rice, retorrefied rice, such as Beanes' Patent Grist, retorrefied barley and other forms of prepared grain."
"A Treatise of Practical Brewing and Malting" by Frank Thatcher, The Country Brewers' Gazette, 1905, page 226.
That's specific enough: retorrefied rice. But what the hell is that? We'll get to that later. First we'll look at what the point in using it was.
""Beanes' Patent Grist” is prepared from rice by a special process of the manufacturers. It imparts to the finished beers a high percentage of dextrin, so that the palate thinness given to beers by flaked rice is entirely avoided, and beers brewed from this patent grist improve in brilliancy and condition the longer they are stored, while their flavour is clean and entirely satisfactory. It yields a high extract and does not produce the defects in beers which are observable in those brewed from other preparations of rice or maize. For the production of pale ales and beers which are required to remain sound during hot weather, this material is indeed an excellent one, as it is already practically converted when the brewer receives it."
"A Treatise of Practical Brewing and Malting" by Frank Thatcher, The Country Brewers' Gazette, 1905, pages 260 - 261.
Right. It was an improved version of flaked rice. One which didn't have its disadvantages and had a few other useful qualities. The high dextrin content would explain why it didn't thin out the body.
Odd that it's use is particularly handy in Pale Ales and in producing clear beers. When you see Cairnes' use of the material: only in there Stouts. Where clarity is not such a big deal.
Here's how it was made, for the more technically minded amongst you.
"Beanes’ Patent Grist is manufactured in the following way;— The grain is steeped in a solution of acid at a certain strength, and after it has absorbed as much of the acid solution as desired, it is washed with water to remove any excessive amount of acidity until the water coming away from the grain becomes neutral to litmus paper. Then the grain is dried on a kiln in a suitable manner, and the temperature raised from 280° to 310º until the starch in the grain has been changed to what is required, the grain being then more or less converted into dextrin. By this unique method of treatment one of the most excellent brewing materials that can be obtained is manufactured. The process appears at first sight a very simple one, but many who have tried to imitate it have failed to produce the exact article with regard to quality as supplied by the original manufacturers."
"A Treatise of Practical Brewing and Malting" by Frank Thatcher, The Country Brewers' Gazette, 1905, page 516.
Now I know what Beanes' Patent Grist was. My problem is what do I use to replace it? Flaked rice, from the texts above, wouldn't produce the same result.
If you look in the comments, fellow beer historian Peter Symons suggests brown rice syrup.