There have been volumes of rubbish written about Scottish beer. Fantasies have become established as fact. Articles like this one aren't going to help:
Let's attack it point by point. His biggest mistake: confusing the shilling Ales of the 19th century with the shilling Pale Ales of the 20th. Yes they were 60/- to 140/- or even 160/- Ales. But these were the thick sweet type of Ales than resembled Burton Ale.
The number of shillings refers to the price per hogshead, not a barrel. And apparently Scottish hogsheads were generally larger than English ones, typical holding 63 gallons. It wasn't the pre-tax price, it was the wholesale price. 1830 to 1880, it couldn't have been the pre-tax price because there was no tax on beer. The tax was on malt and hops.
The weakest shilling Ale (60/- according to Horst) only 1030º.? No it wasn't. The Table Beer brewed in Scotland was stronger than that. These are William Younger's shilling Ales from 1868:
50/- Ale 1040
60/- Ale 1047
80/- Ale 1068
100/- Ale 1076
120/- Ale 1088
140/- Ale 1102
160/- Ale 1116
Parti-gyling. Why does everyone get it so wrong? Younger's brewed most of their beers entire gyle, including the really strong ones. They didn't just use the first runnings. And they certainly didn't blend after fermentation. Blending beer from two different mashes? Nope, didn't do that either.
The strongest beers called Scotch Ale or Wee Heavy? Wee Heavy doesn't appear until the 20th century. The original - Fowler's Wee Heavy - was actually called 12 Guinea Ale. That still appeared on the labels in the 1960's. Wee just refers to the bottle size, a nip. Heavy just means strong. The strongest may have been called Scotch Ale in England, in Scotland they were sold as Strong Ale. Or 6, 8, 10 or 12 Guinea Ale.
The mid-range beers called "Export"? No, totally wrong. It's the Pale Ales that were called that, totally, totally different type of beer. Export does appear in the 19th century, but only really came into common use in the 20th. 70/- has never been called Export. In the second half of the 20th century it was called Heavy.
Twopenny? Does he have any idea what twopenny is? It's a very old Scottish type that was give a special status by the act of Union. It existed as a separate tax category until 1802. In its final days the tax was 3s 4d per barrel, while Strong Ale was 10/- and small Beer 1s 4d. So it was probably about 1045º. The name comes from the price per Scottish pint, which was about 4 English pints. Nothing to do with 60/-. It's easy enough to work out the retail price:
2d for a Scottish pint = 4d per gallon (or a third of a shilling)
54 (the number of gallons in a hogshead) / 3 = 18 shillings retail per hogshead
How could a hogshead that retailed for 18 shillings have a wholesale price of 60 shillings?
That last lot of shilling ales, which period are they supposed to come from? It isn't clear. I think he means now. It which case he got 80/- right. Then again, he doesn't say that it's a type of Pale Ale. And the top of the gravity range is too high. He calls Twopenny, a type of beer that hasn't existed for 200 years, 60/-. It's Light. Even the BJCP gets that right. Calling Strong Ale 90/- only dates to post-WW II. Between the wars 90/- was a relatively low-gravity (about 1035º), bottled Pale Ale. As I said before, Wee Heavy was a 12 Guinea Ale.
Distinguishing different strengths by a shilling designation wasn't uniquely Scottish. Some English brewers - Brakspear is an example - used it in the early 19th century, too.
One final point.The shilling system was used for all different types of beer. There are 54/- Stouts, 54/- and 60/- Milds,
"a traditional, pre-decimal, British currency denomination" that's the only true statement I can find in that article. Oh, and that /- is a way of denoting a shilling. Utter, utter drivel.