Monday, March 27, 2017

Vintage 2017 Update 8

Cabernet Sauvignon is a 'late' variety of Vitis vinifera.
This means it is one of the last to shoot and last to ripen during a vintage.
For us bud burst is late September/early October and we usually harvest late March or even early April.
We therefore run the gauntlet, in our coastal area with its warm maritime climate, of possible wet late summer/early autumn months.
Too much rain means juice dilution which means lower sugar levels which translates into lower alcohol content of the resultant wine.
It also means the risk of fungus diseases eg. botrytis is significantly higher.
Picking these grapes too early leads to thin uninteresting red wines with a distinct vegetative flavour so we always try to keep the spray programme up to date and monitor potential bad weather events in an effort to keep the grapes on the vines as long as possible to reach our 'sugar goal' of 13.5° Baume.
This vintage we had the driest, hottest summer on record. A little relief came in February with some welcome but not totally disastrous rainfall.
March however was a completely different story.
366mm fell over 18 of the first 26 days (a third of our average annual rainfall!).
The berries within the bunches swelled, split and burst and then shrivelled. Expressed juice is open invitation for botrytis and there was quickly evidence of it.

What to do with vineyard tests showing only a Baume of 10° to 11°?
One path was just to leave to grapes on the vine and forget harvest.
Another was to harvest early and 'fix' the sugar level and try to make a Rose'.
Chaptalization is the process of adding white cane sugar to juice to increase the Baume level.
This is a normal procedure in Europe when seasons prevent grapes ripening to a satisfactory level.
The practice is banned in Australia for commercial wines.
Increased sugar levels here can be achieved legally by adding grape juice concentrate.
This is available in different grape varieties and comes with a sugar level of around 35° Baume.
Unfortunately it comes in large containers and is very expensive for us amateur non commercial wine makers.
Of course you can make your own concentrate if you have the right equipment.
Grape juice can be frozen and the ice formed removed (the juice is 80% water).
What remains is a high sugar grape concentrate.
Another method is to boil the grape juice to remove the water. 

So I made to decision to add sugar in an effort to salvage a hard year's work in the vineyard knowing that the wine produced could be of very inferior quality. Sugar ripeness of grapes is not the only criteria for good wine. Less than optimally ripe grapes have other negative influences.
Approximately 20g/L cane sugar will increase Baume by one degree.
So we harvested very selectively discarding or leaving poor quality bunches hang. This took place over two days as we were continually interrupted by rain. I estimate we would have been lucky to have taken off 50% of what was originally a large and high quality crop.
Then we destemmed and crushed into an open fermenter and only then were able to accurately test the Baume level. Vineyard testing almost always produces a higher result.
It was 10°
pH 3.6
So we needed to add 40g/L to get it up to 12.0° ie. potentially 12% alcohol, which is fine for the Rose' style. We decided to aim for a Spanish style rosado ie. crisp, a little fruity yet dry.
We immediately initiated fermentation by addition of white wine yeast and DAP.
After a few hours maceration we were happy with the colour achieved so transferred the must to the press to drain the juice off the skins, stalks and seeds.
Here it was very lightly pressed and the resulting free run juice was transferred into a stainless steel tank. We didn't want a strong colour, just what naturally came from the skins from those few hours of soaking, and definitely no tannin.
From then on the Rose' was treated like a white wine.

Thursday, March 16, 2017

Vintage 2017 Update 7

The Pinot Noir was picked during a short break in the weather on 5th March after 4 days of very heavy rain totalling 125mm.
The was more evidence of botrytis in this variety than in the Semillon. The bunches were extremely tightly packed and the rain has caused some berry splitting encouraging the fungus.
The affected berries were removed from the bunches during the harvesting process.
Baume 13.5° (great!)
pH 3.8 (needs adjusting to 3.6 or a little less by tartaric acid addition)
The grapes were immediately destemmed and crushed and the must (skins, seeds and juice) transferred to a stainless steel tank.
Normally we ferment red wine in an open top fermenter. However we want to let the Pinot soak for some time after fermentation has finished to extract as much colour and tannin as possible. We also want the wine to go through MLF. All this has to be done without any SO2 addition so a sealable tank gives us more oxidation prevention control.
200ppm DAP and 15g/hL rehydrated specific red wine yeast added.
Fermentation began within 12 hours.
The cap was punched down about every 4 hours and any wayward stalks that had found their way into the must at the crusher removed. Alcoholic extraction of stalk tannins can give wine a unpleasant bitter or vegetative flavour.
"Tight" Pinot Noir (L) and "loose" Tempranillo (R) Bunches

The Tempranillo was picked on 9th March.
Fruit was in fair condition after over a week of constant rain but with little sign of fungus. Leaving it longer on the vine to get a little riper was always going to be a gamble this time of year. We thought the dry summer might continue into early autumn but alas....
Baume 13.4° (ok considering the rain dilution)
pH 4.0 (way too high! Needs adjusting as above)
200ppm DAP and 15g/hL rehydrated specific red wine yeast added.
Fermentation started within 12 hours.
The cap was punched down every 4 hours and any wayward stalks removed.
When the Tempranillo is 'finished' we will the press it and the 'soaking' Pinot on the same day saving one clean up.
The free run wine and pressings of each will be transferred to their individual tanks.
After a few days the wines will be racked off their fermentation lees ready for the fining process.

Saturday, March 04, 2017

The Milton Show 2017

We knew it was show time as, after an extremely dry summer, the heavens were predicted to open up with a severe weather warning in place.
I have been going to this two day event for nearly 30 years and inevitably it is wet.
So we went early to avoid the crowds and the mud. It was already pretty soggy underfoot so we only 'did' the pavilions.
The co driver had entered a number of quilts and did well winning quite a few awards and taking out most successful exhibitor.

The other competitive sections were well represented. The art and photography were amazing as usual as was the wood working. There are some very talented artisans in our area.
Then there are flowers, fruit, vegetables, jam and preserves, honey, sewing, rug making and baked goods of all descriptions.
I always like the bonsai.

Outside the livestock were being judged and the numerous horse events taking place but there were hardly any spectators braving the wind and rain.
The deserted sideshows, rides and carnival food booths must have been praying for a break in the weather.
A rodeo was planned for that night but assumed it would have been called off as conditions worsened during the day.
This was the 148th annual show.
Big things are apparently in the pipeline for 2019.
I really don't know what they can be. It's always been virtually the same all the times I have been.

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.
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.
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