Ales and lagers - what's the difference?

There are more than 80 styles of beer, with colours ranging from almost black (dark lagers, stouts and porters) to a very pale gold (pilseners, wheat beers and golden ales). Alcohol content stretches from 0.5 percent for low-alcohol beer to 12 percent or stronger for barley wine - which is beer, despite its name.

All beers are either lagers or ales, depending on the type of yeast and the brewing process.

Lagers are not always more pale than ales: some types of lager are very dark, and some ales are pale. In ales, the yeast fermentation process usually contributes more to the flavour of the beer; in lagers, yeasts have less to do with the taste. The type of hops and malts used also contribute to the taste and style of a beer.

Ales

Traditionally, ales were brewed in wide shallow vessels and their yeasts tended to rise to the top of the fermentation vessel.

Ale yeasts work faster than lager yeasts because they ferment at a warmer temperature.

Most porters and stouts are ales. Porters can be sweet and have a heavily malted and hoppy flavour. Black or chocolate malt gives modern porters their dark brown colour.

Stouts are made with roasted barley and a combination of malts. There are a number of recognised styles including drier oyster stout and sweeter oatmeal stout. Guinness is the most famous example of a dry stout. Oyster stouts may be made by putting a handful of oysters in the barrel.

Lagers

Lagers are traditionally fermented with yeasts that tend to sink to the bottom of fermentation vessels and work slowly at cool temperatures. Before packaging, lagers are stored cold for a few weeks to develop their flavours.

New Zealand "draughts" are essentially reddish brown in colour, and they tend to be sweet. Dark lager styles range from dark brown to almost black.

The distinction between a lager and an ale used to be straightforward. But modern technology is muddying this distinction. Many brewers, especially large commercial brewers where space is at a premium, have switched from shallow vessels to taller, narrower tanks. In these, the yeast tends to distribute itself more evenly throughout the tank, and so the traditional concepts of top (ale) and bottom (lager) fermentation aren't so clear-cut.

The handling of the yeast, the brewing environment, and the temperature at which the beer is fermented are what determine the final style. A lager yeast working at warm temperatures can produce ale-like characteristics.

The great beer debate

Speight's Gold Medal Ale and Tui East India Pale Ale are ales, right? Wrong. Both these beers are New Zealand draughts or "brown beers", which are essentially amber lagers.

Monteith's Original Ale, Speight's Old Dark 5 Malt Ale and Speight's Distinction Ale aren't genuine ales either. Confused? We're not surprised.

DB Breweries and Lion Nathan both stand by the labelling of their beers.

DB told us that brewing in New Zealand has evolved independently from other countries. With modern technology and high-quality ingredients it's possible to make both ale and lager styles with the same yeast strain.

Lion Nathan said overall taste, ingredients, colour, aroma and temperature all play important roles in differentiating styles. They told us they focus on taste when they name their beers.

The New Zealand Society of Beer Advocates (SOBA) has a different opinion. "SOBA recognises that not all beers will fit into a given classic style, but we deplore the practice of blatantly mislabelling beers as different styles simply because the marketing department thinks it will assist sales. This practice is damaging to brewers who correctly brew a style, and perpetuates the long-held myth that all beer tastes the same."

A beer should still taste like what it's claimed to be, regardless of how it's brewed. We think it's time the industry labelled their products true to style.