New World Winemaker Blog

My husband is obsessed with this movie and the theme song. It was his cell phone ring-tone for a while – a long while actually – drove me bonkers. I guess that is why it was the first title that popped into my head when I thought of how to describe Lactobacillus in winemaking. It used to be the bad and in many cases the ugly. If you look at articles on stuck fermentations and wine spoilage from a few years ago, Lactobacillus almost always features somewhere in the article as one of the main culprits. So it is not surprising then that sales attempts to sell Lactobacillus starter cultures for malolactic fermentation are often greeted with GREAT resistance, aggression, jaw dropping, gawking or a call for Security.

Well folks you can pick up your jaws because it seems that there are “good” guys amongst the bad and ugly ones. The two companies that are taking the lead on commercializing some good guys are Oenobrands and Lallemand. The Lallemand culture V22 is a pure Lactobacillus plantarum culture from European origin and can be used for both co-inoculation during alcoholic fermentation as well as sequential inoculation after alcoholic fermentation. The Oenobrands product, marketed under the Anchor brand and called Anchor NT 202 Co-Inoculant, is a blend of selected Oenococcus oeni and Lactobacillus plantarum strains. These strains are South African isolates.

Okay, I know what your minds are screaming…VA! Indeed something to scream about. But not in this case. These two commercial Lactobacillus plantarum cultures are homofermentative. That means they can utilize only malic acid as a carbon source to form mainly lactic acid. Other Lactobacillus strains (often present in spontaneous MLF’s) as well as Oenococcus strains  are heterofermentative, meaning they can also utilize grape sugars and citric acid and as a result form acetic acid. However, reputable commercialized Oenococcus oeni MLF starter cultures, although heterofermentative, strongly prefers malic acid as carbon source (they have been selected because of this), even during co-inoculation where grape sugars and citric acid are present in high concentrations. Not all starter cultures are suitable for co-inoculation though.

Okay so why Lactobacillus? In the case of Anchor NT 202 Co-Inoculant the Lactobacillus plantarum in this mixed culture brings aroma and roundness to the party. The Oenococcus is the workhorse bringing, security and speed to the party. The application of NT 202 Co-inoculant is also rather simplistic. You add equal amounts of sachets of bacteria and packets of NT 202 wine yeast to the juice, at the same time, before the onset of fermentation. No waiting for 24 hours. No extra calculations. Scientific research has shown this Lactobacillus plantarum strain to have a very different enzyme profile to Oenococcus oeni in general and as a result the typical varietal character of red grapes, specifically monoterpenes and norisoprenoids, are released from their non-aromatic precursors, thereby increasing wine aroma and thus quality.

So while you still need to do your best to keep the “bads” and the “uglies” out of your wines, experimenting with the “good guys” might just give you that kick @$$ competitive edge you strive to achieve in your wines…

“Large egg-shaped vessels have been appearing in increasing numbers at high end wineries on the West Coast, stirring a mixture of bafflement, warm, return-to-the-womb associations and fears of an alien invasion…” Field Maloney, Wine & Spirits, February 2009

Very funny intro. Alien invasion is exactly what describes the image that went through my head when I saw these egg shaped tanks for the first time. I immediately thought of the 1993 movie: Coneheads, hence the image.  From the moment I saw a picture of these tanks – and I must embarrassingly admit it was only last year – I have wanted to investigate this amusing (to me) new movement in winemaking. It looks rather funny in a cellar. It looks like a giant hatchery where large prehistoric flying reptiles are about to emerge from any second.

The tanks are made from concrete and they are in an egg shape. Why the concrete? Well apparently concrete allows for a micro oxygenation effect on the wine like barrels do, except without adding wood flavors. Why the egg shape? It apparently creates a vortex in the wine and allows for lees to stay in suspension so stirring is not necessary. Lees in suspension has various advantages, hence the practice of batonnage.

The mastermind behind these tanks is Marc Nomblot who on request of biodynamics winemaker, Michel Chapoutier, built the first one in 2001. This caught on quickly and to use the the description of Jeffrey Iverson, these egg shaped tanks are now “hatching in wineries all over the world.”

I recently visited the hatchery of Boekenhoutskloof winery in Franschhoek, South Africa (yes the eggs have reached the southern tip of Africa). They ferment Grenache blanc in their eggs. They start fermentation in stainless steel tanks on skins, so no settling, and press anywhere from 25 – 50% into the fermentation. The must is then pumped with all its lees into the eggs. Fermentation is conducted at 16 – 18°C; they use a coil for cooling (Franschhoek is a tad warmer than the Rhône). The coil only goes into the egg for about an hour at a time. These concrete eggs are great insulators, compared to stainless steel that is conductive. Fermentation is about seven to ten days with Lalvin ICV-GRE yeast (Lallemand). After fermentation the wine stays in the eggs for 10 months. To the winemaker the biggest attribute from using the eggs is the incredible mouthfeel one can obtain this way.  This Grenache blanc forms part of of a white blend called Wolftrap white. Even though Boekenhoutskloof is not a biodynamic winery they do embrace some of the principles, such as these egg tanks, and plan to expand their hatchery on an ongoing basis. They have also started to expand the usage to other grape varieties.

So certainly with “biodynamic”, “natural” and “non-interventionist” winemaking being the buzz words at the moment, I reckon these eggs are here to stay for a while. Personally I believe in interventionist winemaking, but here is a concept that even makes sense to me. I’m just not so sure about racking during certain moon cycles though. ..

Boekenhoutskloof winemaker Jean Smit and some of their eggs.

Karien O’Kennedy is the Online Communications Manager for Oenobrands and knows the odd thing or two about fermentation and winemaking.

Various parts of dead yeasts can be used as a source of nutrition / alcohol tolerance for live yeast cells during fermentation. Sometimes they are used in combination with inorganic nitrogen such as DAP and sometimes they are used on their own. Here is a short explanation of the different types:

Inactivated yeast – the whole yeast cell has been killed by heat. It contains the cell wall, the cell membrane and the whole inside of the yeast. Inactivated yeasts are a source of vitamins, minerals and to a lesser extend amino acids. As the alcohol content of the must increases during fermentation the dead yeasts’ cell membranes become more and more “leaky” and more of the inside goodies of the dead yeasts leak out to the must where the live yeasts can take it up. This does not happen to live yeasts since live ones can regenerate their cell membranes. They can keep it together so to speak. Inactivated yeasts are found in products such as Fermaid K and E (Lallemand) and Maxaferm and Nutrivin (Oenobrands).

Yeast autolysate – the whole yeast cell is killed and then exposed to lytic enzymes at 45°C for a certain time period. The result is that the cell wall, that contains glucans, is partially degraded and the cell membrane and the “soluble inside” of the yeast are more exposed, and therefore more available, to the hungry fermenting yeasts (cannibals) lurking around for a bite. Commercial examples are Natuferm (Oenobrands), Go-FermProtect (Lallemand) and Dynastart (Laffort). These products are usually added separately from inorganic nitrogen. They are applied for specific purposes and they are more effective than normal inactivated yeast. Apart from the normal role of nutrition they also do the following: Natuferm = aroma enhancement, especially esters; Go-Ferm Protect = source of sterols and Dynastart = aroma enhancement, especially thiols.

Yeast cell walls /hulls / ghosts – this is the insoluble yeast cell wall fraction of yeast autolysate after centrifugation. Depending on the washing process used during the manufacturing of yeast hulls, they may or may not contain parts of the cell membrane. Commercial examples are Extraferm (Oenobrands) and Springcell (Bio-Springer). Technically they are not nutrients, they detoxify the must from medium chain fatty acids produced by sluggish yeasts.

Yeast extract – the supernatant of yeast autolysate or in plain English: the soluble insides of yeast cells once the insoluble cell walls and cell membranes have been removed. This is found in Superfood (Vinotec).

Specific yeast fractions – e.g. mannoproteins. Mannoproteins are a specific cell wall constituent and production thereof requires further processing of yeast cell walls. Technically they are not nutrients either. They assist with tartrate stabilisation and mouthfeel. Commercial examples are Claristar (Oenobrands) and Mannostab (Laffort).

For more detailed info on the topic go the technical article with the same title.

Karien O’Kennedy is the Online Communications Manager of Oenobrands and knows the odd thing or two about winemaking and fermentation.

The cat is out of the bag so to speak. It seems that not all tannins are created equal and quality differences between suppliers exist. Best you make sure you buy from a trusted supplier…

I recently read an interesting (also from a date of publication point of view) article, published in a reputable scientific journal called: “Impact of exogenous tannin additions on wine chemistry and wine sensory character.” They analyzed the effects of a range of enological tannins in Merlot wine. First they analyzed how much of the product sold as tannin was indeed tannin. They found it to be “12 – 48%.” What is the rest of the stuff in the bag that you are adding to your wine??? They found that adding the recommended dosage of the supplier was too little to have a “measurable effect.” They then proceeded to add higher concentrations and concentrations exceeding the supplier’s recommendations. The latter did indeed have a measurable effect on the wine’s phenolic content but also had a “subsequent negative impact on wine sensory character.”

In case I misinterpreted the article, for which I then profusely apologize to all tannin suppliers, here is the link:

http://www.sciencedirect.com/science/article/pii/S0308814611013781

Your thoughts….

Karien O’Kennedy is the Online Communications Manager for Oenobrands. She also knows the odd thing or two about winemaking and fermentation.