This is a fact and opinion collection and sifting exercise, so as to better understand the appellation … it is a work in progress.
Sauternes – the regulations  including some contributory comments
- Quality and characteristics
Sauternes is a still white wine with residual sugar. The essential characteristics are caused by botrytisation of grapes, the botrytis cinerea fungus provoking the biochemical transformation of specific precursor aromatic and gustatory compounds, and concentration of berry sugars.
Harvest, vinification and ageing may only be carried out in the communes of Barsac, Bommes, Fargues, Preignac and Sauternes.
Permitted varieties are muscadelle (adds floral aromatics), sauvignon blanc (adds acidity and aromatics), sauvignon gris (adds aromatics) and semillon (a waxy, lanolin, lemony profile, with lowish acidity), which can be varietal.
Minimum density 6500 vines/hectare.
Maximum grape loading of 8t/hectare before botrytisation, corresponding to a maximum of 12 bunches/vine.
Maximum yield of 25hl/ha (Yquem reckons an average yield of ~9hl/ha, from severe pruning, or one glass of wine per vine – I am assuming 125ml here), and the best properties report yields of 10-15 hl/ha .
Grapes to be harvested when over-ripe (in the presence of noble rot), but the degree of rot/percentage of grapes affected is unspecified. It is suggested, rather than specifically regulated, that a good level of over-ripeness, is indicated by not less than 221g of sugar/litre of must. However, the official analysis and tasting panel introduces a quality/typicity hurdle. If the end of the ripening season coincides with particularly dry and warm conditions, then a degree of raisining may occur, which would help concentrate grape sugars (4). If a vintage has too much botrytis, then some non-botrytised grapes may be included in the vinification for freshness and balance – balancing acidity is essential to bring out the spectrum flavour, if flabby then the palate becomes more 1-dimensional . Young high quality Sauternes has significant acidity for long ageing, and so may appear unbalanced in youth .
Manual harvesting, in successive tries.
Minimum natural alcohol of 15% (this translates as potential alcohol) – a good Sauternes will show alcohol of ~14% and ~4% residual sugar , requiring a potential alcohol of ~18% at harvest.
- Vinification and ageing
There is no regulatory requirement for exposure to oak during fermentation or ageing.
Fermentation is in any vessel, but top château ferment in new oak.
Minimum acquired alcohol of 12% (this must be finished and bottled alcohol), which means a theoretical minimum residual sugar of 3% (at the minimum natural alcohol of 15% above).
Chaptalisation is permitted, but not widely practised.
Minimum residual sugar of 45 g/l.
Minimum ageing of 6 months, which can be in any vessel, again the top château age in oak, new and/or a variety of ages.
Sauternes is a blend, of typically 70-80% semillon, 20-30% sauvignon blanc, with possibly a splash of muscadelle eg by Chateaux Coutet and Rieussec .
Finished wine is subject to independent analysis and a panel tasting evaluation – this will sort out the issue of typicity with respect to the impact of botrytis for that vintage.
- Characteristics of a Sauternes
In youth, golden hued, they develop aromas of flowers eg honeysuckle and broom (vanilla-like), and fruits, then with age, the hue turns to amber and a ‘roasted’ bouquet develops with powerful toasted aromas, candied fruit and conserves eg orange marmalade, citrus and honey, with a very long aromatic persistence . Botrytis can also add high-toned notes of varnish and nail polish, tropical fruits eg mango and papaya, dried fruits and smoke , together with caramelised notes eg butterscotch, caramel, crème brûlée, ginger, roasted nuts and very ripe stone fruit eg yellow peach and apricot. They are very fat and unctuous in the mouth, and keep for decades, but as with all great wines, they are excellent from the time of bottling .
.. and more comments, work in progress …
- I have heard one expert speak, in relation to the presence of botrytised grapes in a dessert wine, of indicative notes of mushroom and earth, but so far, this is uncorroborated by the many tasting notes circulating, and has yet to be experienced by me. And it was this, that made me think I ought to know more about the appellation.
- Some Sauternes producers also make dry white wines based on the Sauternes appellation varieties, these are classed as generic Bordeaux Blanc.
- A few producers have moved away completely from the fickleness of botrytised wine, into the production of more popular sauvignon blanc-based still dry whites. This more productive variety, is another draw.
- Similarly, a few estates are making lighter Sauternes blends, with higher sauvignon blanc content than in the past (it is normally in the minority, and muscadelle even less so at <10%, when used), this is lamented in Decanter , since great Sauternes is tied to (the dominance of) semillon. Dilution with sauvignon gives a fresh citrus profile, but without the richness associated hitherto with Sauternes .
- I was wondering about the relative susceptibility of the permitted varieties, which are all thin-skinned, to botrytis, and  suggests:
- muscadelle – very susceptible.
- sauvignon blanc – highly susceptible.
- sauvignon gris – no information.
- semillon – susceptible.
- INAO, Sauternes, last modified 19/07/16.
- Brook, S. (1987). Liquid Gold, Dessert Wines of the World. Constable, London.
- Brook, S. (1995). Sauternes and other sweet wines of Bordeaux. faber and faber.
- WSET, Study Guide Level 4, Unit 3, Issue 5, January 2010.
- Mercer, C. (March 2015). Bordeaux 2014: First impression – Sauternes savours a ‘unique’ vintage. Decanter magazine [online] accessed 25/10/17.
- Robinson, J., et al. (2012) Wine Grapes. Allen Lane.
Last edited 06/11/17