If there’s one question I’ve been asked more than “what’s your favourite beer?” it’s this: “What’s the difference between lager and ale?”
The easiest way to answer this is a quick history lesson – because if we start with modern beer it gets quickly confusing.
But first, here’s the tl;dr – lager is made with a yeast that creates sulphur notes and ferments away a lot of sugar, ale is made with yeast than can throw off mixed bag of fruity esters and tends not to eat as much sugar as lager yeast leaving a sweeter more full-bodied beer.
A great example between the two styles is to take a good brewery like McLeod’s and compare their Longboarder Lager with their Paradise Pale Ale. The lager, you’ll find, has an initial sulphur note and a smidgin of grassy hop aroma; it’s an easy-drinking beer with clean, dry finish and mild but firm bitterness. The pale ale, in comparison, has a rich hoppy aroma of stone fruits and sweet citrus, is full-bodied, almost chewy and finishes bitter-sweet. The lager should feel refreshing and cleansing, while the pale ale is – relatively – delicious and rich.
But this is just scraping the surface and comparing just two branches of the lager and ale trees – because lagers include moderately-hopped pilsners, malt-rich doppelbocks and the counter-intuitive dark but dry schwarzbiers (think Black Mac, Speight’s Old Dark, Steinlager Black). The ales also spread out across the spectrum to include porter, stout, IPA and Belgian-style ales to name a few. If there’s one over-arching difference I could put my finger on – it would be that lagers are mostly lighter and drier than ales but with the blurred boundaries of modern craft beer that’s a rule of thumb that’s sometimes broken and often bent.
So, to history.
Once there were only ales – originally fermented by wild yeasts in the air, or obtained from the skins of fruit or on the grain. Over what we know as brewer’s yeast put itself forward as the dominant fermentation workhorse thanks to its preference for the sugar, low-oxygen, high-ethanol environment found in beer and wine.
The malty brews made by this yeast were known as ales and it was discovered the optimum fermentation temperature was 18-24 degC. And for a while this looked being “all she wrote” on the subject of beer-making – variations of this ale yeast dominating for thousands of years.
All that changed about 500 years ago when a wild yeast – related to the ale yeast but just a little bit different – hitched a ride on the European ships that ventured down to South American, notably Patagonia.
This yeast, which grew on trees, could also make beer but it preferred cooler temperatures, in the 8-15degC range. It just so happened that German brewers, struggling to keep their beer cool enough during the summer months, stored the beer in caves that offered perfect conditions for this new “imported” yeast to thrive.
Over time, the new arrival took over at these cool temperatures. The brewers discovered the beer tasted different … first it took longer to ferment compared with ale and was more mellow and drier than traditional beer. By dry we mean fewer residual sugars (or in brewer speak: highly-attenuated). The beer also tended to be more stable than ale. Over time, because the beer was dry and crisp it didn’t need as many hops added to counter the grainy sweetness.
Cut a long story short, the Germans became very good at brewing this type of cool-fermented beer and gave it the name “lagerbier”, of beer for storing.
It was some 300 years later – thanks to Louis Pasteur – that the world worked out exactly what yeast was doing to beer. Until then it was all trial and error if you like. Suddenly scientists could specify the difference between ales and lagers – it was the yeast, not the caves nor the storage.
And by then, the world was getting a taste for lager.
About the time Pasteur explained how yeasts worked and scientists were able to sperate and culture separate strains, along came the invention of refrigeration which allowed breweries to deliver lager on an industrial scale – they had the cold-loving yeast and now they could control the temperature.
Before we delve any further it’s important to understand that lager does not mean pale. A lager can be red, brown or black – there are no rules about colour because that comes from the malt. Yeast, my friends, is colour blind. Some of the best lagers in the world are dark – like a black schwarzbier or a deep brown doppelbock. We’ve come to think of lager as pale because nearly “national” beer in the world is a pale lager – they are ubiquitous. Think Heineken, Budweiser, Carlsberg, Stella Artois, Fosters, even our own Steinlager … all pale lagers.
The pale side of things only took off in the early 20th century with mass production of beer glasses. Until the 1930s beer was drunk from pewter tankards but once glasses came into vogue brewers were under pressure to create an ever more pale beer to take advantage of the glassware. Filtration, malting techniques, refrigeration, the science of yeast – they all came together less than 100 years to drive beer towards a caricature of itself.
The pale lager took over the world as the biggest breweries perfected the style and marketed it superbly. Ale continued to exist but almost in pockets – English bitter, Belgian ales, Irish stouts such as Guinness.
Ale made its comeback during the craft beer revolution that grabbed America in the 1980s and reached New Zealand (the first wave anyway) in the 1990s. The American craft movement was built on rebellion against the mainstream lagers – Budweiser, Coors, Miller etc – that dominated the US market.
Key US brewers started playing around older English styles such as pale ale, IPAs and Russian imperial stouts – but they didn’t just bring old flavours to a new world, they continued to up the ante through aggressive hopping techniques.
The demand for hoppy pale ales and IPAs re-defined what an ale could be – along the way some subtlety was lost as hops dominated and traditional ale yeast characters – apple, pear, strawberry, banana – were repressed in order to showcase the hops.
As a result, pales ales evolved to become “cleaner” with US brewers preferring ale yeasts that do their job with throwing off too many esters. Some have gone even further, making “ales” with lager yeasts.
The flipside is that pilsner, a type of pale lager, is going through a renaissance in New Zealand with increased doses of hop aroma and flavour to create a New Zealand-style pilsner that approaches a pale ale flavour profile.
In short, it’s getting harder and harder to tell ales and lagers apart.