Ancestral method

The steps (Clairette de Die)

The Clairette de Die specification describes the method in detail.¹

1. The must starts to ferment in vat.
2. The fermentation is held back by cold and by removing part of the yeast.¹
3. The partially fermented must is bottled in glass, and the same fermentation finishes in the bottle.¹
4. The wine rests in the bottle on its lees for at least 4 months.^1,2
5. The deposit is removed by isobaric filtration "bottle to bottle", or by transfer to a vessel kept at 4 °C or below.¹
6. Nothing is added before closing: liqueur d'expédition is prohibited, so there is no dosage.¹

How the CO2 is produced and kept

There is only one fermentation. The CO2 produced while the must is in vat escapes; the CO2 produced after bottling is trapped and dissolves in the wine. The timing of bottling matters: the fermentation is held back by cold and by removing part of the yeast so that enough sugar is left for the sparkle and for the sweetness of the finished wine.¹ The sugar that makes the gas is the grape's own, not added sugar, because liqueur de tirage is prohibited.¹ The fermentation does not run to dryness: lots ready for market must contain at least 35 g/l of sugar and have a pressure of at least 3 atmospheres.¹

Compare the traditional method, where a dry base wine is refermented in bottle with added sugar and yeast, and the Asti method, where a single fermentation is stopped in a closed tank.

Legal minimums

These figures come from the INAO texts of 2016 and 2023, drafts under national opposition. The 2023 draft is internally inconsistent on whether méthode ancestrale also covers rosé, so that point is left open here. For comparison, the EU "traditional method" term requires at least 9 months on the lees, more than twice as long.³

Where it is used and label wording

The appellation name Clairette de Die may be completed by "méthode ancestrale" only for wines that meet the conditions for that mention.^2,1 A decree of 25 May 1971 separated sparkling wines made by "méthode dioise" from those made by second fermentation; the current specification uses "méthode ancestrale".² The grape is Muscat à petits grains.

Other French appellations carry the name too, for example Blanquette méthode ancestrale, Gaillac and Bugey Cerdon. Their specifications were not reviewed for this page, so their rules are not summarised here. For the modern informal style see pét-nat.