New World Winemaker Blog

Jan van Rooyen, the new winemaker at Avontuur Winery, South Africa (2011 being his first full vintage at Avontuur) is no stranger when it comes to making delicious Chardonnay. As a seasoned vintner with many years experience, Jan plans to make the 2011 Chardonnay at Avontuur a memorable one.

Jan accentuated the fact that he wants to make a wooded Chardonnay this year that is for the Chardonnay lover. In other words, a wine with elegance, power and poise. However, this wine should be fully integrated with the wood without obscuring any of the minerality or the fine balance between the apricot, citrus and coconut components.

Different Chardonnay clones from vines as old as 12 years were being harvested on the day of this interview, at 24.5°Brix. The yield per hectare was estimated at 3 to 4 tons and the juice yield at 650 L per ton. Novoclair Speed (for settling), gelatin and kieselsol are added at the crusher after which the grapes are left to cold settle at 12°C for 24 to 48 hours. Fermicru LVCB (Oenobrands) was selected as the yeast strain, due to its ability to produce a wine with balanced fruit and minerality. After the yeast is added at 15°C, fermentation typically lasts for 3 weeks at a temperature of 18 to 20°C. Jan believes that a clean and steady fermentation is best achieved at this temperature. Nutrient additions are added in the form of Anchorferm (Oenobrands) or Bioferm (Bio Springer) and later liquid ammonia is added to get the YAN up to 300mg/L.

Proper wood integration with the developing Chardonnay is monitored with great vigilance. The wine is kept on the gross lees in the barrel for 12 months, with lees stirring initiated after fermentation is complete. Batonnage is only done for the first 3 to 6 months (depending on how Jan feels the wine is developing) of barrel ageing. Jan is adamant that the wine should rest peacefully after the vigour of harvest and therefore batonnage happens only once or twice a month. All barrels are tasted according to Jan’s schedule and should a reductive barrel be detected (I did mention that Jan is very meticulous), heavy lees stirring is done on the barrel and if possible, the old lees is substituted with fresh lees. An even spread of first, second and third French barrels are used.

After the oxidative stability of the wine has been ensured (typically after 12 months in barrel), it is ready for bottling. Jan describes this process by using an exquisite metaphor; he simply sees the wine leaving the barrel as a rebirth and then the wine waiting in the tank before bottling as a gentle awakening.

Bernard Mocke is a technical consultant for Anchor Wine Yeast.

On the 28^th of February 2011 I visited Groot Constantia wine estate, South Africa, to investigate how winemaker Boela Gerber plans to make his 2011 Chardonnay – the 2006 version of this wine having earned a place in the top 10 of the 2008 Chardonnay du Monde competition. I arrived just in time to see the grapes arriving in small crates.

Boela adds both 50 ppm SO₂ and Vinozyme skin contact enzyme at the crusher – a significant time apart as not to affect enzyme activity negatively. He does only a very gentle crushing so that a big percentage of whole berries enter the press. He prefers this softer action on the grapes and feels it helps him to minimise phenolic characters.  He uses skin contact enzyme to improve yield and flavour. Enzymes according to him have a softer action on grapes than for instance pressing harder, in terms of improving juice yield. The grapes go through a mash cooler that cools it down to approximately 14 °C. Skin contact is as long as it takes to fill the Bucher press, which is about 4 hours.

His final yield is about 680 L / ton after the addition of some press juice. He adds Novoclair settling enzyme and 6 g/hl PVPP in the press sump before pumping it to the settling tank where he settles for 4 days at 3 – 4°C. The juice then has a NTU of approximately 10 and after racking he increases the NTU to 100 by the back addition of fine lees.

20 % of the wine is then fermented natural in old barrels and the remaining 80% is fermented with Lalvin D 47. He uses liquid ammonia (permitted in South Africa) as a source of nitrogen and Anchorferm as a source of complex nutrients during fermentation. The D 47 fermentation starts in tank and is moved to barrel after 1°B is fermented. He uses Francois Ferrer, Dargaud & Jaegel and Mercury barrels, 50 % new and 50% 2^nd and 3^rd fill. Fermentation lasts approximately 7 days. The wine then stays in barrel on the gross lees until November of each year and he battonages by rolling the barrels. Malolactic fermentation happens naturally and is usually 50 – 60% complete. The wine is then taken out of barrel and treated if necessary with Laffort casein and bentonite. In the years where Boela feels either the wine alcohol is too high or the acidity too low, or both, he blends some of his Chardonnay base wine for sparkling wine production from the same vintage into the final blend to assure a better balanced final product. The wine is then sterile filtered and kept in bottle for 6 – 9 months before release.

The wine retails for £11 – 14 in the UK.

PS: I got the title from a four yearly event that Sonoma Cutrer in California used to host/organise. Does anyone know if this is still happening? Google is not very forthcoming on the topic. As a harvest intern at SC in 1994 I had the pleasure of tasting the left over wines from this event every day. Too bad I did not fully appreciate the quality of what I was drinking at the time…