New World Winemaker Blog

Over the years, South African winemaker, Henry Kotzé, has refined his winemaking mantra to one of minimal interference and maximal expression of variety by means of selecting the best terroir possible. Experience speaks for itself and Henry was appointed winemaker at Morgenster in 2009. Previously, Henry’s oenological skills were honed during his stints at Vergelegen, Boschendal, Neil Ellis and Eikendal (all highly acclaimed South African wineries.) Henry’s focus at Morgenster is on red wine where he works with the classical Bordeaux grape varieties (Cabernet Sauvignon, Cabernet franc, Petit Verdot and Merlot) and Italian grape varieties (Sangiovese and Nebbiolo).

The first vines on the farm were planted in 1994 and the average age of the vineyards is 15 years. The grapes are usually harvested, depending on the fickle weather of course, late February. Average yield is 5.5 tonnes per hectare and juice yield is 700 litres per tonne.

Now, let’s get started with the winemaking section of this blog. This is what Henry had to say: “As the grapes are destemmed and crushed (about 10% is whole bunch pressed), I’ll add an Enartis red wine enzyme for colour extraction. Cold soaking is done for two to four days at less than 10°C. Only one pump-over a day is needed and this is done slowly and gently, to facilitate maximum extraction.” As he says this, he glances longingly at his mud encrusted mountain bike and then back to me. I realise that he’s probably very busy and has not been getting a lot of sleep (the plight of every winemaker!), so I hurry on with my questions. As for the Bordeaux varietals, Henry elaborated about two of his favourite yeasts: “I inoculate Anchor NT 202 and Anchor WE 372 (Oenobrands) at 15°C. NT 202 has always been a stalwart and works well with the wine style that we like to embrace at Morgenster. It is also easy controllable with temperature alterations.

As for WE 372, it is a slower fermenter which really enhances the varietal character of the grapes I am working with. WE 372 makes a particularly powerful contribution towards red berry and fruity aromas when I’m working with Merlot. For my Italian varietals, I use selected Lallemand yeasts. A typical fermentation is done at 26 to 28°C for seven to ten days. I also use a lot of oxygen during fermentations for maximum colour extraction. As an activator I use Laffort Dynastart and Anchor Nutrivin (Oenobrands) and DAP during fermentation.” Henry also formed part of a group of winemakers in South Africa who tried the new Anchor NT 202 Co-Inoculant MLF starter culture (Oenobrands) in 2011.

He says: “I tried the Co-inoculant on a batch Petit Verdot this vintage and was pleasantly surprised with the results, since MLF took only 14 days to complete after AF finished. This usually takes three to five weeks. I usually inoculate all my red wines with Lallemand bacteria, but intend to use the Co-inoculant again next year and in bigger amounts.” Henry explains post-AF as follows: “Extended maceration on skins can last a few days or up to two weeks. After MLF, the wine is racked and three rackings are done during 18 months of barrel ageing. Beta-glucanase (Enartis) is used during ageing.

Optimal filtering would be done with a 1.6 micron candle filter, but where VA is 0.6g/L or higher, I will use a 0.45 micron candle filter.” Henry has his wine bottled during December and January after which it is released three years later. As for the premium Morgenster wines, expect to pay US $69 and US $33 for the Lourensriver Valley range.

Bernard Mocke is a technical Consultant for Anchor Wine Yeast.

Gerhard Swart, Flagstone’s winemaker, is no stranger to awards. His Free Run Sauvignon blanc has consistently received high accolades over the past years and this comes as no surprise considering the care that goes into his Sauvignon blanc.

Let’s take a closer look at how this wine is made. The Sauvignon blanc is harvested from vineyards that are 8 to 12 years old during February and March. Yield is 6 to 8 tonnes/ha. Upon arrival, the grapes are stored overnight in a cold room at 0 to 2°C. The cool grapes are then fed into the crusher under a carbon dioxide blanket. Rapidase Expression (Oenobrands), sulphur dioxide and ascorbic acid are added sequentially at the crusher. Tannin Galacool is added during crushing when Botrytis infection is evident.  The crushed grapes and juice is then pumped into a skin contact tank and kept at 2 to 4°C for 18 hours. Free run juice from the skin contact tank is pumped to another tank and skins are pumped to a Velo Evolution Press (the press was designed so that grapes can be pressed in a reductive environment of nitrogen gas). Viniclar (PVPP, Laffort) is added to the free run juice before settling. The press juice is then pumped to another tank. Fining agents such as Polylact (PVPP and casein) and gelatine are added to the press juice. Settling enzyme, Rapidase Vino Super (Oenobrands) is added at the settling tank and this lasts for 2 days at 12 to 13°C.

All Sauvignon blanc fluffy lees is combined and kept at 3 to 5°C. Total sulphur dioxide levels are kept at 35 to 40 ppm. After sheet filtration of the fluffy lees, fermentation is initiated and Turbicell is added to increase the NTU level (sheet filtration decreases this too much and can lead to nutrient deficiencies). A typical minimum NTU level of 80 to 100 is sufficient for Sauvignon blanc ferments.

Gerhard uses the following yeasts for his Sauvignon blanc ferments: Anchor Alchemy I and II (Oenobrands) contributes floral, gooseberry and tropical flavours; Anchor VIN 7 (Oenobrands) makes a big contribution towards tropical aromas; X5 (Laffort) adds boxwood, lychee and passion fruit aromas; QA 23 (Lallemand) makes a contribution similar to the Alchemy yeasts and VL 3 (Laffort) produces a waft of khaki bush. Different yeasts add complexity to the wine. Dynastart (Laffort) is added at yeast rehydration and Nutristart (Laffort) is added when needed. Thiazote (Laffort) is added in 3 stages: after 3°B has been fermented, at 16°B and at 12°B. Inoculation is done at 12 to 13°C and fermentation at 12 to 16°C. Fermentation lasts 2 to 3 weeks after which ageing on gross lees (2 weeks) and fine lees (3 to 4 months) follows. Evolution in wine aroma is monitored during fermentation and ageing by regular tasting and chemical analysis.

The Sauvignon blanc is stabilised at the end of June, bottled at the end of July and released in September. Protein stability is done after final blending, right before bottling. All Sauvignon blanc is treated with bentonite after blending.

The Free Run Sauvignon blanc sells for £10 in the UK.

Bernard Mocke is a Technical Consultant for Anchor Wine Yeast.