The Storing Fault: Maderisation L'Ortolan
Here L'Ortolan Sommelier Stephen Nisbet continues his discussion of basic wine faults, and explains just what it is that can make 'that special bottle' go so horribly wrong.
Simply because they way we transport and store wine has improved vastly in the last ten years this last fault is unlikely to affect new bottles. So if you're buying all your bottles fresh then your dinner party wine should be safe. However, those bottles that you may have been brought by a friend, or the ones you have been saving under the stairs for a special occasion are especially susceptible - and this last fault is maderisation.
This occurs when the wine has been kept in a temperature that is too warm - in other words, when it has been stored over 18 degrees. As soon as you get over 18 degrees, you get an accelerant affect on the wine, and if the temperature becomes even higher (over 21-22 degrees) then the wine is literally warm, and something is changing in the wine.
If the bottle feels warm to the touch then you are at risk of almost simmering the wine, and this can completely alter the composition, changing the flavour.
Maderisation is when the wine has developed this cooked flavour - you may receive the bottle cold, but when you open if you get stewed-fruit, prune-y smells then you know the wine has become maderised. You will often see this raisin-y reduction character normally in port, sherry and particularly Madeira- but it is designed to be there. In Madeira they literally cook the wine. It is allowed to age in warm places, sometimes in specially heated rooms for a few years to introduce this factor. It's almost a kind of curing process for the wine, fortifying and strengthening it. The fragile elements of wine are the fruity esters that make young wine so pleasant, and you get rid of these by warming or oxidising them out - which obviously changes the flavours, meaning that when it is in the bottle, like a spirit, it will not change much. It has travelled past the point in no return, but because it has the sugar and the alcohol it doesn't matter. However, there is a problem when this occurs in a wine that doesn't have the sugar, because it's been fermented out, or doesn't have the alcohol - the wine isn't designed to develop this flavour.
So if you keep your wine near a radiator, or an oven, or anywhere in a house that has heating you are risking maderisation. Places like under the stairs are also really bad for wine. Even though you wouldn't have a radiator in these cubby holes, they are often riddled with hot water pipes. It doesn't even need to be a lengthy period - just a few weeks above a certain temperature is enough to cause the change to occur, and your wine to be ruined.
Fine wine is particularly susceptible to maderization. It tends to have a longer shelf-life, and so will get passed around a lot more than a younger bottle, which leave it open to poor treatment. Provenance is like art - a lot of good quality respectable merchants know that the wine that they buy is of good quality, and they can trace it back - but unless you are a wine trader you are never going to know how the wine you are about to enjoy has been stored throughout its life. Even I have to take it on trust a lot of the time.
Although a symptom of maderised and oxidised faults, older wines also tend to develop some darker colouration. However, the wine will smell generally healthy. Older fine wine is breaking down and dying, however it has been constructed in such a way as to be able to get to that point without becoming unpalatable.
To prevent maderisation, be aware of how you've stored your wines, and for your dinner party - unless you can be 100% sure they have stored it correctly and have ideal cellar conditions in their house - it may be best to find a polite way to avoid serving your guest's bottle.