It's That Time of Year Again

The grapes are starting to ripen and we are preparing for harvest.
Tests have shown that the Semillon is at 10.2 degrees Baume', Pinot Noir at 10.0 and Tempranillo at 9.8. It's too early to test the late ripening Cabernet Sauvignon.
If we get a few weeks of dry weather and sunshine then two more degrees Baume' for the white and three for the reds would be perfect.
But we have had the wettest summer on record with weeks and weeks of rain and cloudy days.

This has slowed up the ripening process mainly by the vines absorbing water and diluting the grape juice.
Also unfortunately the weather has completely disrupted our spraying program and for the first time ever we have a concerning amount of fungus in the vineyard.
One, although recently it has been classified as an algae, is downy mildew, Plasmopara viticola.
This shows up as a white deposit on the underside of leaves.
It attacks the leaves and eventually kills them and they drop. Without leaves the grapes will not ripen.

Another problem fungus is Botrytis or grey rot or bunch rot.
Botrytis cinerea results in a disintegration of grape berry structure and creates the ideal conditions for the infection of the fruit with yeasts and bacteria which increase volatile acidity
and laccase activity. The musts obtained from infected grapes are strongly compromised both microbiologically and chemically. This shows up as laccase enzymes, a high concentration of apiculated yeasts, acetic bacteria, lactic bacteria and high concentrations of gluconic and acetic acid.
The most important wine making problems are caused by the presence of laccase, an enzyme that oxidises wine polyphenols.
As an indirect consequence it causes the production of acetaldehyde, the reduction of the free sulphur dioxide, an increase in "faded" aromatics, the loss of primary aromas, the darkening of white wines, and an increase of orange notes in red wines.

So we have a bit of a battle on our hands this vintage to produce reasonable wine.
And why is downy mildew now an algae and not a fungus?
Because it needs water to sporolate and spread and it can produce its own food through photosynthesis.
Fungi feed on other organisms.
OK, enough microbiology, back to getting tanks, the destemmer/crusher, buckets and press cleaned up and ready.