Green beer isn't just a cheap parlour trick for St. Patrick's Day any more.

Progressive beer-making companies across Canada are making their operation more eco-friendly. Yes, drinking beer can actually help the Earth: much more carbon dioxide is absorbed by ingredients grown for beer than is created by the brewing process.

But your choice of beer and where you drink it makes a big difference in how righteous you should feel. Each of the breweries profiled here has reduced its carbon footprint in innovative ways, such as giving empty grain husks, left over from the brewing process, to local farmers for cattle feed. Read on to learn about environmental stars in four green brewing categories.

Calgary micro-brew

Wild Rose Brewery & Taproom (wildrosebrewery.com) offers a near best-case scenario for beerdrinking: it sells draught beer produced on site minutes from downtown using all-natural ingredients and no preservatives, with most of those ingredients coming from farmers in Alberta and Saskatchewan.

Wild Rose even reuses its hot water. During the brewing process, cold water flows through a heat exchanger to cool the wort, heating up as it does so. This newly hot water is stored and used to start the next batch of beer. Any overflow from Wild Rose's boiler system is captured in an old keg.

The taproom's decor is recycled industrial, with most of the tables, chairs and lighting fixtures created from decommissioned brewing equipment and vehicles (think lamp shades made from small kegs cut in half and a bar made of beer tanks).

The brewery has also reduced its carbon footprint through office initiatives such as recycling paper, replacing fluorescent light tubes with low-wattage bulbs and switching from plastic to paper bags and takeout containers.

Medium-sized Alberta brewery

At Big Rock Brewery (bigrockbeer.com), a craft beer-maker based in southeast Calgary, every ingredient but the hops is supplied locally. The water used to make the beer is city water put through carbon filters and reverse osmosis to remove any chlorine and organic materials.

The brewery uses a fermenting process that captures carbon dioxide for natural carbonation. This saves the energy that most large-scale carbonated beverage-makers expend to artificially carbonate by compressing the gas or buying it from another company and trucking it to their brewery.

Cooling water from the brewing process is recovered, topped up in temperature and added to subsequent brews. Waste water is also recovered and mixed with waste beer to create natural fertilizer for a local farm.

The brewery recycles its maintenance oils and grease, cardboard, beer cans and bottles.

Energy-intensive equipment is run during off-peak hours to put less stress on the power grid. And Big Rock provides compostable cups made from corn resin at outdoor community events where its beers are served.

Brew your own

The Vineyard (thevineyard.ca) has two Calgary stores selling beer-brewing kits and dry ingredients to brew from scratch.

The main benefit of brewing your own is that it encourages recycling and cuts down on fuel used to get beer to your tummy. Enthusiasts usually wash and reuse their beer bottles several times. Most of the beer-brewing kits at The Vineyard come from Vancouver, and most of the raw ingredients come from farms around Calgary. You can make about 23 litres of beer from a kit that weighs about 15 litres. Or you can make the same amount of beer from 4.5 kilograms of dry ingredients.

The only green drawback to brewing your own is that heating small batches of brew for an hour or two on your home stove isn't as energy-efficient as a brewery heating thousands of litres at once.

Distant but eco-conscious

Yes, Steam Whistle Brewing (steamwhistle.ca) is based in Toronto, so its beers have to be trucked about 3,400 kilometres before they can be picked up in a Calgary store. But if you're going to drink beer from far away, this is the most innovative ecobrewer out there.

Steam Whistle's trucks use bio fuel. The company also offers bottles made with thicker glass that can be refilled 35 times (about twice the industry standard). The logo on each bottle is painted, so no label paper, glue or dyes are wasted in each bottle washing. A new brewhouse has cut the company's waste water output by a third.

On hot summer days, the building is cooled by water drawn from intake pipes deep in Lake Ontario, instead of energy-hog conventional air conditioners. The well-named brewery uses steam -the most efficient form of heat -to heat water for brewing, bottle washing and even building climate control. Energy-efficient fixtures, bulbs and motion detectors cut down on power usage. And the brewery uses clean, renewable power from wind and low-impact hydro generators.

All of the company's packaging is recycled into new packaging. Steam Whistle started the use of biodegradable corn resin cups at outdoor events in Canada. Leftover edibles from Steam Whistle's frequent parties go to a nearby street mission or a women's shelter to reduce waste.

Oh, and the beer is pure: only all-natural, non-genetically modified ingredients for this Pilsner.