Alcohol consumption was somewhat “necessary” during the Regency Era, as well as before and after that particular time period. Water obtained from public sources was unsanitary. The Georgian England site tells us, “The growth of cities and towns during the 1700s placed enormous pressures on the availability of cheap housing. With many people coming to towns to find work, slum areas grew quickly. Living conditions in many towns consequently became unimaginable. Many families were forced to live in single rooms in ramshackle tenements or in damp cellars, with no sanitation or fresh air. Drinking water was often contaminated by raw sewage and garbage was left rotting in the street. Problems with the disposal of the dead often added to the stench and decay. Many London graveyards became full to capacity, and coffins were sometimes left partially uncovered in ‘poor holes’ close to local houses and businesses.”
Cholera and typhoid epidemics were common, both diseases caused by contaminated water. Therefore, many did not drink from a public water source or from any “fresh” water source. Waste and fecal matter still found their way into public streams, rivers, and water supplies.
Jane Austen’s World tells us, “Those who drank ale, beer, wine, or a fermented drink, since the fermentation process killed almost all bacteria. Until the 16th century, the most common choice of drink was ale. By the end of the century, beer had replaced ale in popularity. Housewives and cooks gathered their own recipes for making beer, wine, cordials, possets, punch, spirit waters, and other distilled spirits, although these drinks could also be bought commercially. Fermented beverages were stored in containers similar to those in the photo above. Hops were added to beer to make the beverage last longer in storage. Interestingly, hops acted as antibacterial agents, making the beverage safe. In addition, real ale, or un-pasteurized beer, rich in nutrients, vitamin Bs, and minerals, was as nutritious as food.”
People were known to drink ale with each meal of the day. Keep in mind these products were not as potent as those we consume today. “Small beer, a term used to describe a weaker second beer, averaged an alcoholic content of only 0.8%. This concoction was obtained after the first brewing had used up almost all the alcohol from the grain. The product from the second brewing was 99.2% water and tasted nothing like our beer today. Small beer was consumed by people of all ages and strata in society, even children. Recipes for stronger drinks existed, but they were too expensive for ordinary people, taking twice as much grain to produce.”
Other drinks included cider and mead. Wine was the drink of the wealthy. It was imported from France and Germany and so it was expensive. Wine was also imported from the Eastern Mediterranean. It was called Malmsey wine, which is a corruption of Monemvasia, a town famous for its wine.
Another popular drink in England was sherry, which was known as sack and as brandy. In Scotland, whisky was a popular drink. In the 17th century, new drinks were introduced to England. Gin was invented in Holland early in the 17th century. It was introduced into England in the late 17th century. Gin soon became a very popular drink. Drinking cheap gin became endemic in the early 18th century, causing many social problems as shown by the picture Gin Lane by William Hogarth. However, gin-drinking was curtailed after 1751 when a duty was charged. In the early 18th-century porter became a common drink in London and Guinness was first brewed in Dublin in 1759. Another drink, champagne was invented in England in the late 17th century. Drinking rum became common in Britain in the 18th century. The British navy gave sailors a daily rum ration. (A History of Drinks)

Port became very popular in England after the Methuen Treaty of 1703, when merchants were permitted to import it at a low duty, while war with France deprived English wine drinkers of French wine. British importers could be credited for recognizing that a smooth, already fortified wine that would appeal to English palates would survive the trip to London. In 1678, a Liverpool wine merchant sent two new representatives to Viana do Castelo, north of Oporto, to learn the wine trade. While on a vacation in the Douro, the two gentlemen visited the Abbot of Lamego, who treated them to a “very agreeable, sweetish and extremely smooth” wine,” which had been fortified with a distilled spirit. The two Englishmen were so pleased with the product that they purchased the Abbot’s entire lot and shipped it home. The continued British involvement in the port trade can be seen in the names of many port shippers and brands: Broadbent, Cockburn, Croft, Dow, Gould Campbell, Graham, Osborne, Offley, Sandeman, Taylor, and Warre being amongst the best known. Shippers of Dutch and German origin are also prominent, such as Niepoort and Burmester. The British involvement grew so strong that they formed a trade association that became a gentlemen’s club. (Tom Stevenson, “The Sotheby’s Wine Encyclopedia,” The Fourth Edition, p. 334, DK Publishing, 2007)
Up until around 1802 all the wine from abroad had to be imported in casks to be bottled in England. Though the beverages were allowed to be imported in bottles after that, most importers continued buying wine in casks. The smugglers usually brought in wine in casks and kegs. Bottles are much more difficult to handle. They were heavy and noisy when they rubbed against each other and were easily broken. Wine could not be drunk immediately, as it had to settle so it was delivered to a bottler who acted as wholesaler.
I can see how this might play out depending on an individual or family’s wealth. The wealthiest could afford to buy entire casks for their private cellars, whereas the not-as-wealthy might buy smaller quantities in individual bottles from a wine merchant to stock their cellars, and the not-wealthy might only be drinking their own home-made wines and beers, probably in bottles they cleaned and reused. I am relatively certain the variations would depend on the particular beverage. I know most of the champagne people drank in the Regency was made in England by adding extra sugar into imported French wine and then bottling (or re-bottling) it for additional fermentation. They used the “sparkling wines,” not the “bubbly kind,” generally imported through Portugal. Champagne does not do as well in casks as did other beverages.
Also, the wire cage and cork affair sealing champagne bottles had not been invented. It was known as “The Devil’s Wine” because of the frequency of explosions caused by the fizz.