Making Botrytised Wines

Botrytised dessert wines or “stickies” are some of the most sought after and expensive wines in the world. Leading the way at around $500 a half bottle is the legendary Chateau d’Yquem Sauternes from Bordeaux. Great Trockenbeerenauslese (TBA) wines from Germany can be just as expensive and just as sought after. With such a noble standing the world, these wines have inspired winemakers all over the world to both emulate them or surpass them.

Despite their prestige, to most consumers the process that creates them remains a mystery.

Botrytised wines can be made from many different varieties. The most important requirements for selection of the varieties to be utilised in botrytis wines are colour, skin thickness, bunch size & density and ripening time. The main varieties used are Semillon, Riesling and Chenin Blanc.

The natural creation of botrytised wines in the vineyard is like living on a knife’s edge. There is no certainty that the ideal weather conditions will be met – that is misty, damp mornings and warm, sunny afternoons. There is no certainty that the botrytis rot will set in at the period of grape ripening – too early and the rot will ruin a whole crop. Many other factors including reaching optimum rot level and quantity picked that also need to be considered.

When God’s grace ensures all those conditions are in the favour of making “sticky”, the noble Botrytis cinerea goes to work. The fungus attacks the skins of the grapes slowly developing and acting as a replacement skin with a porous nature that promotes the evaporation of water from the grapes. Botrytis cinerea also metabolises some of the acids within the grapes resulting in berries rich in sugar content with a stable level of acidity. Botrytis cinerea also imparts other compounds and properties on the grapes it infects – most notably a higher level of glycogen. Picking of Botrytis infecting grapes usually requires individual bunch selection, though for the greatest Sauternes’ and Trockenbeerenausleses, picking of perfectly ripe, individual berries may take place.

With all these issues it is no wonder that many new world produces are starting the replicate ideal weather conditions for Botrytis infecting in the winery after the grapes are picked.

Large quantities of grapes are required in the winery to produce small quantities of botrytised wine – as with most “stickies“ due to the evaporation of the water. The higher sugar and glycogen content result in an extremely viscous “juice”. Fermentation usually stops of its own accord when the stress becomes just too great for the yeast to continue, leaving a wine with significant residual sugar and an alcohol level between about 9 to 14%.

For all this effort you would hope the results (and the resultant price!) are worth it, so it is probably fitting that the world’s most recognised Botrytis wine – Chateau d’Yquem Sauternes – be that proof. After being discovered in a “bricked-off” pre-revolution Paris cellar, wines destined for then US President Jefferson from this great Chateau showed their class by remaining at their peak, from a dramatic tasting in the late 1980’s, aged well over 200 years old!

However, Chateau d’Yquem Sauternes is a miniscule proportion of the botrytised wines made the world over, so what can you expected from the rest.

Broadly speaking, wines with good aging ability. Perhaps more than any other wine style (Ports aside) botrytised wines – particularly the better examples – can age well. When young these wines extrude characters of honey and cabbage leaves, before developing into rich, golden wines full of things like fresh & dried apricots, honeycomb, raisins, marmalade, flowers etc, etc, etc. Good Botrytised wines will demonstrate a remarkable balance between sweetness and acidity, making them luscious, yet refreshing in the same instant.

In terms of variation of styles, Sauternes sits at the top, but Barsac, it neighbour in the Bordeaux region mustn‘t be forgotten. Further north the Germans have their Beerenauslese and Torckenbeerenauslese, while back across the border, Alsace produces the Riesling based Sélection de Grains Nobles.

Hungary has their Tokaji (not fortified wine Australian Tokay).

In Australia, the Riverina area around Griffith has shown amazing potential with Semillon ‘stickies’. The best examples of which are De Bortoli ‘Noble One’ and Westend Estate ‘Golden Mist’ and Lillypilly Estate

But some of the most exciting stickies in the world are those of New Zealand, made predominantly from Riesling. Produced primarily out of Marlborough these wines are consistently out pointing their Australian rivals with luscious, yet delicately balanced wines.