Invercargill Brewery has produced a Saison farmhouse ale. Saison is French for season. Over the centuries, farmers would produce a beer in spring to bring out a few months later to refresh their workers during harvest. It was, for obvious reasons, low strength (about 3.5%).
The traditional farmhouse ale was aged for more than two months (although Invercargill's was for only six weeks because of shortage of tank space).
Its Saison, without worrying about keeping workers sober during the work, is 6.5% strength and has fresh-peeled orange zest added. This produces an aroma of hop and orange and the beer has a nice balance of malt and hop flavours with a tart orange and spicy bitter aftertaste.
The brewery recommends pouring it cold. At garage temperature on a chilly evening the orange and hop character is not so pronounced and the brew is more warming.
Another Saison Belgian farmhouse ale, made by Brasserie St Feuillien, also breaks with tradition with its 6.5% strength. This one has a lovely fruity malt flavour which is better appreciated at garage temperature rather than from the refrigerator.
The Invercargill Saison is available from the brewery (and at other outlets found on its website) at $5 a 330ml bottle; the Belgian version I found at Castle Macadam in Dunedin was the same price for a 250ml bottle.
Both use a Saison yeast which, without the influence of hop or other ingredients such as Invercargill's orange peel, produces a spicy aroma and mild fruity flavour.
The water, type of malt and hops influence what a beer is, but it is a fungus (yeast) that has most of the say and that is why breweries take great care of their yeasts to protect them from contamination by other, air-borne wild yeasts to ensure that each batch comes out the same as the last.
Some yeasts produce spicy characters such as, for example, cloves; others, fruit characters such as bananas (as in wheat beer).
One of the two main types of yeast ferments at the top, more quickly and at higher temperatures and tends to produce longer-lasting and higher strength beers such as ales and stouts.
The other ferments at the bottom, more slowly and at lower temperatures and is used mainly for lagers because it produces a smoother and drier drink. (Until the 1400s in Europe beer was not made in winter because, without today's refrigeration and heating, it was too cold for yeast to work. Then the bottom-fermenting type was discovered and lager was born.)
During fermentation the yeast converts the sugars of the malt into alcohol and creates carbon dioxide (the bubbles). As the alcohol strengthens it kills the yeast although most brews run out of sugar before that happens. Beer yeasts survive up to about 10% alcohol, but some wine yeasts will keep producing alcohol until the volume exceeds 20%.
But they can also produce characters such as green apple, cooked vegetables, sulphuric rotten eggs or burnt matches that brewers, and drinkers, do not want. So, making beer might be an art, but controlling fermentation is a science.
