Variety or Uniformity?

Beer wasn't just in short supply in WW II. It was also short on variety.

The main reason for the reduction in choice was beer zoning, the system by which brewers had their distant pubs supplied by other breweries. Which is some areas had the effect of introducing a local monopoly.

"Variety or Uniformity
Apart from questions of war damage, the zoning arrangements, following upon the large degree of voluntary exchange of houses previously undertaken by breweries in the interest of transport economy, have resulted in a great many people finding themselves unable to obtain their accustomed brew. Doubtless most breweries will resume the supply of their own licensed premises and their other customers with their own beers as soon as may be. Although the considerations of petrol and tyre shortage make it imperative that long journeys should be avoided wherever possible in war time, it is not in normal circumstances an uneconomic proposition for a brewery to supply its beer over a wide area, and there is every reason to suppose that breweries will wish to do so as soon as it is practicable. From the point of view of the public it is right that there should be this resumption of free choice. In ordinary circumstances the public expects, and has the right to expect, to be able to choose between several alternatives, and the public is quick to detect, or imagine, it detects, subtle differences between the products of different breweries."
The Brewing Trade Review, September 1943, page 268.

Of course, after the war the biggest threat to diversity and choice was the brewers themselves. The mergers and takeovers of the 1950s and 1960s created many local monopolies of near monopolies. Like Watney in Norwich, for example. The tied house system made reduction in choice pretty inevitable.

Shortage of materials had led brewers to prune the range of beers they brewed, eliminating stronger or less popular beers.

"It would be desirable, too, that the range of beers from a given brewery should be fully resumed when the arbitrary restrictions made necessary at present by the shortage of materials are removed. How far this will be possible must depend a great deal upon the policy of the Government after the war in the matter of the beer duty. In 1939 the average beer paid a duty of a trifle over 2d. per pint; the average! beer of to-day—an appreciably lighter product—pays more than 7d. per pint. It is questionable how far, while the present heavy beer duty is in force, the public could afford to return to the qualities of beer which it consumed before the war. Immediately after the last war the duty was increased, not reduced; In 1914 it stood at 7s. 9d. per standard1 barrel; when the war ended it stood at 50s., which was increased in 1919 to 70s. and in 1920 to 100s. Not until 1923 was there a reduction of 20s. on the bulk barrel. When it is remembered that the present duty on a standard barrel is 281s. 10.5d., however, one realises that there may be very little in common between the problem of the beer duty after the last war and that which will have to be faced when this war ends. One is led by the frequent references to the subject to believe that the prosperity of the people generally will be tackled more successfully in the days to come than it was 25 years ago, and this may well go far towards counterbalancing a beer duty disproportionately high in comparison with the general level of the cost of living, whether that comparison is with 1939 or 1914."
The Brewing Trade Review, September 1943, page 268.

The author was pretty astute to point out that beer duty continued to rise after the end of WW I. Because something similar happened after WW II.

UK tax on beer 1943 - 1949
Year	Tax/Std. Brl	tax pint	Total Tax £
1943	281s 10.5d	5.96d	209,584,343
1944	286s 5.5d	7.20d	263,170,703
1945	286s 5.5d	7.42d	278,876,870
1946	286s 5.5d	7.54d	295,305,369
1947	286s 5.5d	7.13d	250,350,829
1948	325s 5d	7.24d	264,112,043
1949	364s 4.5d	9.10d	294,678,035
Source:
1955 Brewers' Almanack, pages 50 & 80.

Though the rate of tax was remarkably stable between 1944 and 1947.

Just as with the WW I, there was never a return to pre-war strengths. And brewers never reinstated all their beers.

For example, Shepherd Neame brewed 8 beers pre-war, but only six after it, dropping a strong Pale Ale and one of their Stouts. It was even more extreme at Fullers, where half of their eight pre-war beers disappeared for good.