Wednesday, February 06, 2013

Vintage 2013 / Harvest Gets Closer

We have been busy testing the grapes for ripeness.
Ripeness can mean a number of things. To most, sugar ripeness is the criteria. This means when the sugar level gets to a certain stage that produces a wine with suitable alcohol content then it's ready.
To others there is flavour ripeness to also consider. That is when the grape is exhibiting its typical varietal characteristics. To get both these happening at the same time is the goal.
My first ripeness runs are simple ie. walks around the rows with sample tastings from a selection of berries from random bunches. It's easy to tell when the sugar level is not quite there. There are 'green' flavour characteristics with a distinct malic acidity showing through.
During follow up walks, I look at the stalk of the bunch for colour change (brownish rather than green) and during a taste for sweetness look at the seeds for maturation (again dark rather than green), then I test the juice which I squeeze onto a hydrometer.

This gives me the sugar level in Baume' (a degree of density) which in turn gives me an indication of the final alcohol content of the wine ie. 13 deg Be' should be around 13% alcohol.
We look for a level between 13.0 and 14.0 deg Be' with the exception of Semillon when around 11.5 deg Be' suits the wine style we like to make.
This is a good indication when a final test should be made.
The final test is more exhaustive. We take a larger representative sample ie. grape berries from the top, bottom, outside and inside of many bunches, crush them and let the juice settle before testing.
We usually find that at harvest the Be reading is always about 1.0 deg below that of the test.
Some think pH (acidity) is also a critical test.
In warm climates like ours, pH will always be high ie. outside the required range for wine making.
We can adjust that with acid addition (allowed in Australia) during the wine making process.
So it looks like we will be harvesting the Tempranillo, Semillon and Pinot Noir in the next week or two.
The Cabernet has a long way to go. It will be late March, I suspect, before it is ready.

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