Wednesday, March 01, 2017

Vintage 2017 Update 6

The Semillon was harvested on 20th February.
We threw in a few buckets of Chardonnay that has been growing 'rogue' in the Cabernet Sauvignon block since its planting and have rejected all attempts to graft the latter variety onto it. More the grafter's fault than the graftee I will admit although he did manage to graft six different apple varieties onto the one tree at one stage.
The grapes were in excellent condition. There were very small incidences of botrytis where the bunches had been growing under a denser canopy. Obviously the hot dry season had a lot to do with this positive outcome.
Affected berries were easily removed 'on the run' with a flick of the points of the picking shears during the harvest.
Yield was down a little.Vines that had been 'grazed on' by kangaroos early in the season had not produced fruit on the secondary shoot regrowth.
Analysis:
Baume 11.0°(good for the style of Semillon we want to produce ie. Hunter Valley / low alcohol, fruit driven)
pH 3.34 (excellent with no adjustments necessary)
The grapes were immediately destemmed and crushed, then the must was drained, lightly pressed and resultant free run juice and pressings transferred to a stainless steel tank.
Additions:
At the crusher - 50ppm each SO2 and Ascorbic acid (to protect juice from oxidation and wild yeast fermentation)
After crushing - 15mL/tonne pectic enzyme (to increase juice yield from the must).
To the tank - 200ppm DAP (yeast nutrient), 0.2g/L PVPP (absorbing and precipitating polyphenols responsible for browning) and 30g/hL rehydrated white wine yeast culture.
Fermentation began within 36 hours.


Then there is always the post harvest/wine making clean up. All the equipment needs to be dismantled and hosed clean. Any residue encourages the proliferation of 'nasty' wild yeasts like Brettanomyces, Kloeckera and Candida genera and unwanted bacteria like Acetic acid, and Lactic acid bacteria eg. Lactobacillus sp. Leuconostoc sp.and Pediococcus sp.
The marc (skins and stalks) were thrown back onto the vine rows. They are a good soil conditioner and contain residual potassium.
Ferment finished on 27th February when 50mg/L SO2 was added and the tank sealed to let the settling process begin

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