There was a strange phenomenon at the end of the 19th century. Suddenly all these Stouts appeared on the market aimed at the sickly and infirm. They come under a variety of names - Nourishing Stout and Invalid Stout were particularly popular. But Maclay seem to have come up with a beer in this vein that was a genuine innovation: Oatmalt Stout.
They were very enthusiastic about it:
"THE BEVERAGE OF THE CENTURY! PROTECTED BY HER MAJESTY'S ROYAL LETTERS PATENT.
OAT MALT STOUT, CELEBRATED FOR ITS NUTRITIVE AND RESTORATIVE PROPERTIES, IS BREWED AND BOTTLED SOLELY BY
MACLAY & COMPANY, Limited,
THISTLE BREWERY, ALLOA.
BY THE MEDICAL FACULTY IT IS STRONGLY RECOMMENDED
The Eminent Analyst, Dr STEVENSON MACADAM, F.R.S.E., &c, pronounces it to be a "Highly Nourishing Beverage, Rich in Invigorating and Strengthening Properties."
And one of many Unsolicited Testimonials received states that - "Its tonic properties are fully demonstrated in the marvellous results produced by its use in convalescent and in chronic wasting diseases, where its nourishing and stimulating effects are admirable. Its delicate flavour renders it palatable to even the most sensitive palates."
B.M., CM., Edinburgh University.
IT IS ADMIRABLY SUITABLE FOR EITHERIts remarkably sustaining and restorative properties render it of inestimable value.
LUNCHEON, DINNER, OR SUPPER.
TO THE WEAK THE AILING, AND THE CONVALESCENT
It Is brewed from Malt produced from the Finest Scotch Oats.
Its remarkable tonic properties are due to super-excellence of Hops used.
Its general superiority is attributable to skilful manipulation, and the entire absence of narcotic.
OBTAINABLE FROM ALL VINTNERS AND LICENSED GROCERS.Falkirk Herald - Saturday 23 January 1897, page 2."
TO BE HAD IN FALKIRK FROM JAMES JOHNSTON, GROCER AND WINE MERCHANT, 174, H1GH STREET.
Oat Ale had existed as a regional beer in a few locations, including Yorkshire. But it seems to have been brewed domestically rather than commercially. What's the total number of times I've seen oats mentioned in 19th-century brewing records? Zero.
So Maclay's Oatmalt Stout seems really to have been new. Sorry if I keep repeating it. I'm so unused to that. Finding something new. Most "innovations" are nothing of the kind.
Now here's a funny thing. I've just checked Whitbread's and Barclay Perkins' brewing records. First time oats appear? 1910 for both breweries. That can't be a coincidence. It seems that the success of Maclay's new type of Stout spawned imitations. Though, as the brewery were keen to point out, they had a patent on Oatmalt Stout. And they were prepared to defend their rights:
"TO WINE AND SPIRIT MERCHANTS AND OTHERS,Which is doubtless why Oat Stout and Oatmeal Stout were such popular names amongst other brewers: to dodge Maclay's patent.
IT having come to our knowledge that a Preparation not of our Manufacture is being placed on the Market as "OAT MALT STOUT," Public Intimation is hereby Given to all whom it may concern that the Sole Right to manufacture OAT MALT STOUT, or to USE this term, is secured to us by HER MAJESTY'S ROYAL LETTERS PATENT, that on and after this date any INFRINGEMENT of our PATENT RIGHTS, either in Manufacture or Sale, will at once be followed by proceedings for our protection.
MACLAY &c CO., LTD.
Alloa, 20th November, 1897. "
Falkirk Herald - Saturday 27 November 1897, page 1.
London Oat Stouts were very different to Maclay's. At least if Whitbread and Barclay Perkins are typical. Whereas Maclay's contained a considerable percentage of oat malt - 13% in the 1905 version - in London they used token amounts of flaked oats. Usually not more than 3% of the grist and sometimes lower than 1%. To little to have any impact at all on the finished beer.
I'm not sure how long Maclay's patent lasted. Because in 1946, the Walmer Brewery had a beer called Oatmalt Stout:
"THE WALMER BREWERY. MESSRS. THOMPSON & SON Ltd., beg to announce that in compliance with the latest instructions issued the Ministry of Food to mitigate to some extent the present shortage of beer, they have decided to discontinue the brewing of XXX and Black Velvet altogether.
The saving thus achieved will result in increased total output which will be applied XX and Oatmalt Stout.
It must be pointed out however, that these small increases will not materially affect the present situation of beer shortage. Even if the recent 15% cut were completely restored they would still be unable to meet the increased demand which is now far above 100% of the datum year."
Dover Express - Friday 02 August 1946, page 10.
I need to dig further.