There needs to be as high a sugar content in the grapes as possible before the order will be given for the pickers to get started and if the weather is fine the champagne makers will often wait a few extra days, before starting to pick, so that the grapes can soak up a little extra sunshine that will boost the sugar content.
They usually aim for a potential alcohol level of 10, that’s to say an amount of sugar that, after fermentation, will produce a wine containing 10% alcohol.
Gauging just the right time to harvest is a matter partly of science – samples of the grapes are taken regularly in the weeks running up to the harvest in order to analyse the sugar content – and partly a matter of luck: you may decide to wait a few extra days to allow the sugar content to creep up that little bit more, only to find that the weather takes a turn for the worse and the sugar level starts to fall again. Then you find yourself wishing that you’d decided to start picking earlier.
That may just be what is happening now…
I was at Champagne Moussé & Fils in Cuisles today - an excellent grower champagne maker who specialises in Pinot Meunier - and learned that the sugar content in the grapes picked yesterday afternoon was 9.8, but today it’s back down to 9.2. That could be because they’re picking in a different plot than yesterday, but it could also be down to last night’s rain.
Be that as it may, there’s another issue to bear in mind.
It’s a late harvest this year and the leaves are already showing signs of turning colour and that adversely affects the plant’s ability to photosynthesize and produce sugar, so the sugar level in the grapes is unlikely to go back up again – at least not much. So, at Moussé & Fils they’re keen to get the rest of their grapes in as soon as they can.
Last, but not least, is the question of rot.
This year the grapes are looking superb with hardly a trace of rot. It’s a far cry from 2010 when a very large proportion of the crop was affected by rot, as you can see from the picture on the right. However, rot can set in quickly especially if the weather is wet and warm and those are exactly the conditions we had today.
Given the choice between rotten grapes with a high sugar content and healthy grapes that are a bit lacking in sugar, the healthy grapes win out every time. So there’s no time to waste to get the rest of the harvest in and it will be go, go, go in the vineyards and press houses for the next several days.
In the next few days I'll tell you more about Moussé & Fils and tell you how the champagne makers can get around the problem of low sugar levels in the grapes. So, do come back again soon