“ When people ask me what bliss is, I simply tell them this is!” The music-hall song, set to a tune from The Merry Widow, celebrates champagne, and is featured on English wine expert Hugh Johnson’s excellent TV and video series called Vintage.

Yes, great champagne is absolute bliss. As a drink it is light and quite dry. Yet it has complexity of flavour and richness without being sweet. It has a great quality attribute called persistence - the ability to linger on your tastebuds for some time after you have swallowed it.

The famous region in France called Champagne is known for the world’s best sparkling wines. There are other good sparkling wines produced around the world, but these are not champagne. Some countries use the same grape varieties and adopt the winemaking techniques of Champagne. Some, such as Asti Spumante from north-west Italy and Cava from northern Spain, have their own grape varieties and production techniques. Australia and New Zealand produce some wonderful sparkling wines, and generally winemakers follow the techniques of Champagne.

Can the best wines of Australia and NZ be identified as different to Champagne by taste? Are they as good? And anyway, what makes a good sparkling wine?

The last question, ‘what makes a good sparkling wine?’ is the easiest to answer. A good fizz has complexity and subtlety of flavour. These traits are created by a natural fermentation, using a blend of good base wines, and then a long period of maturation.

All good sparkling wine obtains its fizz naturally, from the fermentation process. Fermentation is where yeasts eat up sugar and create alcohol. Carbon dioxide gas is given off as a by-product. A normal table wine vat may be open and the escaping gas can be seen bubbling on the surface. However, if the fermentation is done in a closed container, then the gas cannot escape and it dissolves in the wine, thus creating the fizz.

Sparkling wine starts off as a still ‘base wine’ - a non-fizzy wine. It is made from a first fermentation much the same as normal table wine. Some producers mature the wine for a period in oak barrels; many others make and store the base wine in stainless steel tanks. Champagne itself is a very cold region, in fact the coldest in the world for winemaking. The grapes have a high natural acidity as a result and the corresponding fresh taste gives the wine a distinctive style.

Some producers judge their wines to be too acidic and they treat the base wines to a process called malolactic fermentation, where the harsh malic acid is converted to soft lactic acid and the wine tastes richer and creamier. Pol Roger, for example, allows a malolactic ferment to occur but still has quite firm acidity in the flavour. Christian Pol-Roger calls a good acid level “the nervous system of the wine”. Pol Roger takes time to develop as a result, and is known as ‘a lazy wine’.

In Australia the best sparkling wines tend to be blended from several regions. To be in balance, a rich complex sparkling wine needs high acidity in order to give freshness. Lesser sparkling wines tend to have the high acid but without the flavour complexity and hence they can taste thin and sharp. In champagne, high acid is retained yet grapes can achieve high ripeness and flavour. In Australia the quest by quality sparkling producers is to use grapes from regions as cool as possible. The Hanging Rock Macedon Cuvee is made from cold climates in the Macedon area to the north-west of Melbourne. Hardys’ Arras has a big component of Tasmanian wine. Domaine Chandon is based in the Yarra Valley of Victoria but obtains grapes from Tasmania, Tumbarumba near the NSW ski fields and the southern tip of WA.

Various base wines are blended in order to give complexity of flavour. Some has malolactic character; some has been aged in oak. Batches of wine are from various sub-regions. The three grapes used are chardonnay, pinot noir and pinot meunier. The latter two are black-skinned grapes but with care, a pale-coloured juice is obtained, though this juice still has some of the richness of flavour from dark grapes. The cold weather of Champagne meant that in many years, the crop was unable to ripen properly. To overcome this a technique was developed using the addition of reserve wine. Batches of wine from previous warmer vintages are kept back in reserve for future years. Hence most champagne is made from multiple vintages and is called ‘non-vintage’. A similar procedure is followed in Australia, although the labelling laws allow a blend inclusion of up to 15 per cent from other years and the wine can still be labelled as a particular vintage. Hence many Australian sparklers have a vintage year but still contain a small component of reserve wine.

Blending options for sparkling wine are many. Blending decisions can include the grape varieties, the grape origins, whether to oak age or have malolactic character, and whether to include reserve wines. Complex blending is a hallmark of quality sparkling wine.

A key aspect of quality sparkling wine is its maturing. Once the blending has been carried out, the wine is bottled with a little sugar and yeast and a second fermentation occurs inside the bottle. The gas produced then cannot escape and it makes the wine fizzy. The yeasts run out of sugar and die off. They create a sediment at the bottom of the bottle called lees. If the sparkling wine is then aged for a long period with the lees present, the wine takes on richness and complexity.

Champagne laws require a minimum of two years of such ageing, though many producers take longer. In Australia, premium wines may have two to four years’ ageing on lees. Eventually the bottles are tipped up and shaken so that the lees rests against the cork - a process called riddling. The neck of the bottle is then dunked into a freezing liquid causing the wine in the neck of the bottle to freeze. When the crown seal is removed, the internal pressure causes the frozen plug of wine to fly out, taking with it the trapped sediment and leaving behind a clear fizzy wine. The bottle is then topped up with more of the same wine with a little flavour additive, called liqueur, and then finally sealed using a wire clip to hold the cork in place.

In Champagne in good years there is great balance between high ripeness while maintaining high acidity. The winemaking processes of sparkling wine, particularly champagne, tend to build up lots of taste complexity and the high natural acidity gives a balancing freshness to the taste. In a masked tasting it is difficult to tell apart the top Aussie wines from champagne, however I find that the acid taste test reveals inherently higher acid in champagne. This balance is a key element to quality and where the cold climate of Champagne gives an edge over other regions. However, top Aussie and NZ sparklers are becoming better and better. But while there is a crossover where the best Aussie wines are preferable to lesser, imported wines, the top champagnes remain unchallenged.