Not still wines, but pot-still wines!
A "vin de chaudière" has very special qualities...

Your attention please.

A "vin de chaudière" - or a "pot-still wine"- dedicated to be distilled is not what you would usually call a great wine. I am afraid it is even the opposite. To produce beautiful eaux de vies, the wine you distil must be acid, low in alcohol, (8° -10°, or 8-10 TAV) and not very aromatic. I am sure you are puzzled : meagre wines to make exquisite spirits, to produce these cognacs high in flavours? Yes, a « vin de chaudière » (chaudière stands for boiler) would be a very disappointing table wine.
But nobody asked you to drink it!
Have you ever contemplated drinking the wash used to elaborate whiskies?

Their characteristics makes them highly suitable for distillation: acidity favours chemical reactions, low degrees are considered better for concentration of aromas.

Another important point: these wines are the most "natural" wines you can find: nothing is added during their making. You are certainly aware that all wine makers around the world add sulphites to the wines at some stages to protect them from bacteria, oxygen etc.

In Cognac, this is strictly forbidden; here we cannot tolerate rotten grapes, crushed pips, or sulphur, because all of them would cause off-odours. In a table wine, these bad smells might be so weak that no human nose (even a Californian advocate's nose) would be able to perceive them; but in an eau de vie, a spirit concentrated by distillation, the odours would explode.

So the processes used here to make wines are extremely respectful of the grapes.

One varietal dominates

A handful of grape varieties (I will deal with this subject later in Cognac Magazine section) can be legally used to produce Cognac eaux de vies. But 98% of the vineyards are planted with one single variety, called Ugni Blanc.
I see again wine-lovers becoming more and more sceptical: low wines? One varietal only? What about diversity, what about aromas? Don’t be so impatient!