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…

Yes yes, it has arrived. The first commercial bacterial blend has seen the shelves so to speak. It has been commercialised by Anchor Wine Yeast and is a blend of Oenococcus and Lactobacillus. This product is also to be used in co-inoculation with the wine yeast only and not for inoculation after alcoholic fermentation.  Anchor takes it even a step further and recommends it with a specific yeast only. Okay so every man and his dog already have MLF cultures. Why should one even consider this product?

The Oenoccoccus and Lactobacillus cultures are South African isolates and the research was done by the Institute for Wine Biotechnology in Stellenbosch, South Africa. They were isolated from high alcohol high pH wines that underwent successful natural MLF. Why? These are often conditions associated with new world red winemaking; therefore making this bacterial blend very suitable for conditions such as these in other parts of the world. But I’m a European / New Zealand winemaker, I don’t have high alcohol, high pH conditions so what would I bother? Well I guess for the same reason that not everyone in the USA where the speed limit is 65 miles per hour drives a Ford Ka. Some people actually do drive faster, better performing cars in slow conditions. It’s about the ride they say – so much more comfortable in a Mercedes CLK. When you ferment a must with a potential alcohol of 14% its comforting to know that the yeast you use is actually resistant to 16%. The same goes for using this bacterial culture blend.

Okay moving along to the next argument as to why it’s a good idea – Lacotobacillus has a higher pH optimum (3.5 – 4) than Oenococcus (3.2 – 3.5). That means in higher pH conditions, faster onset of MLF since the Lactobacillus will kick off first. And no – the Lactobacillus is homofermentative meaning it only converts malic acid to lactic acid and not sugar to acetic acid. By the time alcoholic fermentation is finished MLF is either completed or down to 1 g/l or less of malic acid. MLF is then completed a few days later. Meaning much faster processing and protection of the wine against Brett for instance.

Not convinced yet? The Lactobacillus also smells and taste good. Trials done comparing the Oenococcus on its own and the blend shows increased aromatic complexity in the favour of the blend. The blend also shows increased aromatic complexity when compared to other commercial MLF starter cultures.

Another differential is that the culture is inoculated with the yeast at the same time. No need to wait 24 hours as long as sulphur addition at crushing does not exceed 50 ppm. That should not be a problem for most people. Anchor also recommends the bacterial blend, known as NT 202 Co-Inoculant,  with the wine yeast NT 202 seeing the this yeast is very stimulatory for MLF, amongst various other positive attributes. The whole idea is to have completely trouble free MLF’s. We will just have to wait and see – this might just end up being the Holy Grail of MLF. Exciting times!