First Quarter Protégé Report – Mahalia Matshete, 1st year


As this is my first harvest as a CWG first year protégé, it is the start of a journey where I’m excited to discover the extraordinary diversity of grape varieties and terroirs, together with the diversity and richness of wines produced in South Africa.

Harvest at Ernie Els started on the 9 February 2015, Three weeks earlier than normally expected.

We received grapes for the following 6 weeks, with the last grapes received on the 18 March 2015 calling it a wrap, but not according to Louis Strydom, the winemaker at Ernie Els. He believes that harvest only ends when malolactic fermentation is done, all wines sulphured and all wine vessels full and topped, meaning 2015 vintage is still ongoing. In total we harvested 325 tons.

Amongst my responsibilities during harvest, was to do all the additions upon receiving the grapes, monitoring fermentation including barrel ferments and wine analysis. The quality of the grape was good, intense in colour and rich in flavour, with optimal phenolic ripeness.

Ernie Els farms predominately red wines, so they employ phenolic maturity to decide when to pick/harvest. Phenolic maturity takes into consideration the colour of the skin and taste of the seed, which will yield red wines with ripe and pleasant tannins. Everything on the farm is hand harvested which allows optimum quality due to selection process during the picking. A big influencing factor for producing their quality wines is the health state of the vineyards. The total yield harvested was less than expected; this is possibly due to the fact that there was more control concerning irrigation, hence a decrease in berry size. This never the less improved the quality of grapes, because small berries give big taste.

When the grapes got to the cellar, we added the following:

·         Enzymes: they help break bonds of pectins between the grape cells, to increase juice recovery and colour extraction and therefore assist in production of full-bodied red wines that are rich in colouring matter and structured tannins, destined for aging.

·         Bisulphite NH4 400: is ammonium sulphur based that acts an anti-oxidant and preservative.

·         VR Supra: facilitates the structural improvement of the mid-palate, inhibits natural oxidation of enzymes (laccase, polyphenol oxidase) and is an anti-oxidant providing protection f the must and pigmented matter. Help with colour stabilization...

·         Oak powder which is mainly used to stabilise red wine colour and enhances oak flavours in wine also help balancing the wine taste.

Yeast selection

Amongst the things learnt this harvest, is the important factors that one should consider before deciding on choice of yeast being the initial grape sugar concentration because some yeasts are not cultivated to ferment high sugars or let alone fructose. Together with fermentation temperature control which controls the tempo of the fermentation, and affects flavour composition. Yeast nutrition is also as important because it facilitates the yeast throughout the fermentation process ensuring a healthy ferment. The exercised regime at Ernie Els is to supplement yeast nutrition in three intervals during the fermentation process, Diammonium phosphate together with a nutrient complex (Fermaid K and Ancho-ferm) is used as yeast nutrients.

1st supplementation is done after the sugar has dropped by 2 balling

2nd supplementation is done after the sugar has dropped by 5 balling

3rd supplementation is done after the sugar has dropped by 8 balling.

Co-inoculation and Fermentation

After the grape must is inoculated with yeast, 24 hours later, MLF bacteria is added to the fermenting this is known as Co-inoculation, and this is done because the medium is favourable for bacteria responsible for the malolactic fermentation. Temperature is than carefully monitored. This is critically important because fermentation is an exothermic process, thus producing heat, if the temperature is not monitored the wine can ferment too warm and the quality of the wine compromised. Warm fermentations lack character, together with the terroir that is hoped to be captured in the finished wine, while cooler fermentation temperatures help preserve the uniqueness of the fruit and helps the character and terroir shine through. Cooling jackets and cooling plates are used to regulate the temperature during fermentation and our temperatures were regulated between 20°- 28°C. Sugar levels are also monitored from the beginning of fermentation, because those sugars are converted into alcohol. This was done using a hydrometer, five times a day.

Punch down techniques is used for mixing, which helps with colour and flavour extraction. The maceration period is targeted at 10 days, but this dependant on the logistics in the cellar. The responsibility that comes with working with small berries, is to avoid over extraction of undesired harsh tannins due to the juice and skin ratio, Therefore frequent punch downs were avoided, which would result in a wine that is albeit, supple and velvety with an enhanced mid-palate and fruit flavours. Pump-overs were divided 5 times a day with, one at 07H00 : 10H00 : 14H00 : 17H00 : 22H00.Once the wine is 5°B and below, pump-overs are done twice a day, is this is practiced to limit over extraction of undesired tannins, but only desired tannins and secondary flavour compounds.

Because of the different wine range and style, maceration time will vary accordingly, thus influencing maceration time. Once the winemaker is happy with the contact time, the wine skins are pressed. The pressed wine contains more course phenols, hence the bitter tannins and astringency. This wine will be blended with the free fun wine, which will give the wine more tannin structure.

Once pressing is done, we wait for the completion of MLF and this is signified by small bubbles in the wine. To ensure that we have reached 100% MLF, wines are sent in for analysis, and if confirmed by the analysis, the wine is racked, Sulphured and tanks/ barrels topped and that’s a wrap.

We also did various barrel fermentation experiments; the whole idea around barrel ferments was to encourage carbonic maceration, which imparts a unique character to the wine. We fermented whole bunch grapes and de-stemmed berries. Careful attention was given to these wines, from temperature control to handling of the skins and preserving the carbon dioxide gas on the cap of skin by using dry ice and sealing the barrel lids. The positive outcome will be that they will be able to be used as new building blocks of creating wines that will add new dimensions for future reference.

In Conclusion this has been a great harvest, a much knowledgeable one, where all the theory was put into perspective and a better understanding of wine was gained. Linking the viticulture aspect, terroir, cellar works as to how to handle the grapes and overall working with a great team. This harvest has developed a quest to discover the diversity and richness of wines produced throughout the world.