Inside this ceramic bottle made to look like a copper brewing kettle is a beer aged for up to 22 years in sherry, brandy, cognac, bourbon and scotch casks. The Boston-based brewer Samuel Adams releases new batches of the strong brew every two years. With its suggested retail price of $200 (about 190 euros), this sought-after strong ale is the most expensive beer in the United States.

The Scotland-based brewery BrewDog has been setting records for years; when it was released in 2009, this was the world's strongest beer. Imperial stout is frozen, then the frozen liquids are removed to leave behind more alcohol - inspiring the name. It's to be enjoyed in small servings, just like "a fine whisky, a Frank Zappa album or a visit from a friendly yet anxious ghost," its creators say.

De Struise Brouwers is a Belgian microbrewery. Their Black Damnation series is made from a dark Russian imperial stout beer, and among their different brews, VI - Messy is the strongest, with 39% ABV. It has never been released commercially, but connoisseurs who've tasted it at beer festivals say it still actually tastes like a real beer, compared to other very strong brews on this list.

Competing against BrewDog, the German brewery Schorschbräu was one of the two serious contestants in the arms race to create the world's strongest beer. It had already demonstrated its will to push the limits of beer with its Schorschbock 31%, an Eisbock stronger than any other beer available when it was released in 2008. Their 40% version was brewed at the end of 2009, beating BrewDog's Penguin.

BrewDog released this even stronger beer a few months later, in 2010. In a clear reference to its German competitor, it was named after the Nazis' largest battleship. It is described by BrewDog as a "quadruple IPA that contains four times the hops, four times the bitterness and frozen four times." At a 100 euros ($105) a bottle, it's also at least 40 times more expensive than a conventional beer.

Aiming to end the battle for the world's strongest beer with this 55% blond Belgian ale, BrewDog also added a controversial visual touch to The End of History by encasing each beer in preserved roadkill. Only 12 bottles were initially made in 2010. New editions were released for a 2016 crowdfunding campaign. Supporters who invested $20,000 in the company were rewarded with this collector's item.

Schorschbräu upgraded to a Schorschbock 43% in 2010 and retaliated with a yet stronger beer in 2011, the Schorschbock 57. The German brewer claims it would be impossible to reach a higher ABV without violating Germany's 500-year-old Beer Purity Law, which they apply in their creations. Only 36 bottles of this beer were initially made, each costing 200 euros (about $210).

Dutch brewer 't Koelschip, which translates to "the refrigerated ship," has also created a few ultra-strong beers. This one was released a month after The End of History - its name, Start the Future, was an obvious reference to its predecessor. The limited batch was also reasonably priced: 35 euros a pop was a bargain compared to the 750 euros for each bottle of BrewDog's dead squirrel creations.

Another Scottish brewery, Brewmeister, tried to claim the title of the world's strongest beer by releasing a line called Armageddon in 2012. However, lab tests demonstrated that ethanol - pure alcohol - had been added to the product. It has since been removed from Brewmeister's lineup.

In 2013, Brewmeister replaced its previous strongest beer, Armageddon, with the stomach-burning Snake Venom. One bottle is equivalent to drinking 15 shots of hard liquor. A label on the bottle recommends not exceeding 35 milliliters in one sitting. Not for purists, this beer is considered unratable by the site RateBeer as the Scottish brewer also admitted to correcting its ABV with pure alcohol.

Germany is a beer country — and that's a fact. Using only four ingredients as per the 1516 German Beer Purity Law (water, hops, barley, yeast), German brewers have managed to create over 5,500 brands of beer. And that number is growing — a new beer is released on the market every week. But Germany manages quantity as well as quality: No other European country produces more beer.

When it comes to drinking alcohol, whether at an office party, during intermission at the theater, or just relaxing — as pictured here in Berlin's Görlitzer Park — beer is always an appropriate choice in Germany, as it can be consumed legally in public.

Funfair stalls, brass bands and "Schlager" music are the ingredients of a traditional German festival, which can be a challenge to get through unless you consume plenty of beer! For such occasions, regional breweries often create a festival beer. The best known of these is probably the Oktoberfest beer, which is made especially for the festival in Munich and served in one-liter Bavarian beer mugs.

Football is also a celebration, and beer goes with football the way mustard goes with a bratwurst sausage. It helps fans celebrate and consoles them if their team loses. At any stadium, the link between football teams and breweries is obvious: Beer advertising features on the players' shirts and banners. And in many Bundesliga football arenas the beer brand sponsoring the team is also served.

In the Ruhr area it's known as a Trinkhalle, in Mainz it is called a Büdchen and in Berlin it goes by the name of Späti. These neighborhood kiosks sell newspapers, tobacco, sweets and usually beer. What began more than 150 years ago as a place to sell water now serves as a pit stop for big city beer drinkers.

Berlin's corner pubs, like the Willi Mangler in the Schönefeld district, are a part of German beer history. They have also become something of a cult. The combination of stuffy air, no-nonsense food and a crowd of regular bar flies is what makes them so charming. Tourists rarely venture here, but local residents often come to enjoy an after-work beer.

Beer gardens are also traditional to German beer culture. These days they can be found all over Germany, but they originated in Bavaria at the beginning of the 19th century. Back then brewers served their beer straight from the cooling cellars along the banks of the Isar River. Especially on hot days the cellar beer gardens were popular among people from Munich.

In Bavaria, where the German Beer Purity Law was adopted in 1516, beer has been an established part of life for centuries. Today, Bavaria has more than 600 breweries, more than in any other state in Germany. During the Middle Ages the breweries were firmly in the grip of the monasteries. Some of these still exist, the oldest being Weltenburg Abbey on the Danube.

Traditional breweries have now been joined by more experimental beer makers like Georg-Augustin Schmidt. His microbrewery "Braustil" in Frankfurt produces small amounts of new varieties which have powerful aromas and are usually made with regional, organic ingredients. The craft beer scene is especially strong in Hamburg and Berlin, but local craft beer can be found across Germany.

Those who are crazy about beer beyond drinking it will find more than 30 beer museums, beer hikes and beer brewing seminars in Germany. You can create your own beer at the "Grillakademie" craft beer seminar in Bochum. Participants also learn about the different varieties of beer as well as German brewing traditions and, of course, the German Beer Purity Law.

To mark German Beer Day on April 23, here's a quick guide. From left to right: the Berliner Weisse goes in a bowl-shaped glass, Kristallweizen wheat beer in a tall glass, lager is served in a beer mug, followed by a short glass for the dark Altbier, the small, narrow glass for the Cologne Kölsch brew, the rounded glass for Pils beer and finally the Bavarian half-liter beer mug.