One of the biggest ideas of recent times has involved ageing beer in oak although, again, this is a practice that was common centuries ago. For various reasons – not least the need to improve cash flow and save valuable space at the brewery – the idea fell out of favour during the 19th century.

As with the fruit beers mentioned above, the process would have created a notable sourness as natural bacteria worked their magic and great examples of this style of oak ageing thankfully still exist in the form of Rodenbach Grand Cru and Verhaeghe Duchesse de Bourgogne from Belgium, two highly-refreshing, tart beers that have been made this way for many decades.

As today’s adventurous brewers are finding, even where bacteria do not play a part, this ageing process slowly reduces the influence of the hops and allows instead the tannins and creamy vanilla notes of the oak to come to the fore, adding a new dimension to the beer.

Often the casks have been used for storing a spirit before the beer is introduced. The flavour of the spirit then tends to shine through so some beers really can have a strong whisky or brandy taste. Scottish brewer Innis & Gunn specialises in this field, with a range of beers with different ‘finishes’, including Innis & Gunn Rum Finish and Scotch Whisky Porter. From the US, Goose Island’s Bourbon County Stout and The Abyss from Deschutes – an imperial stout that is aged in both bourbon and Pinot Noir casks – are other highly acclaimed beers.

Some brewers cut out the casks completely and just use stronger liquor as an addition on its own. Wadworth has a rum beer called Swordfish, brewed initially to commemorate 100 years of naval aviation in the UK and spiked with the rum that was once rationed daily in the Royal Navy.

Beer is such an accommodating drink – it can be sweet, bitter, light, heavy, malty, hoppy and much more – that any number of additional ingredients can be used to enhance its natural flavours and take it to a new level. There are lagers with the burn of chilli, stouts enriched by liquorice, strong ales sweetened by treacle and many other such creations. I don’t think we’ve yet been treated to an aniseed amber, a mustard mild or an elderberry export but it can only be a matter of time.