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Home , Brettanomyces, Wine fault

UPDATE

Number 1 – 2011

NEWS FLASH

❖ A new biological tool to encourage aroma intensity and longevity has been ® How to Prevent developed by Lallemand. OptiMUM-White is a new, specific inactivated , rich in glutathione, which has proper- ties and polysaccharides. The result of a new, natural, optimized production process that enhances glutathione bioavailability, OptiMUM-White® is added to the must at he consequence of the develop- Zygosaccharomyces, Candida, Brettanomyces, the earliest stage of alcoholic ment of Brettanomyces bruxellensis etc. As the wine evolves during fermenta- (AF), after settling. OptiMUM-White® helps T in is a major threat to wine tion, so does the microorganism popula- limit the oxidation of colour and aromas. quality. These undesirable , which are tion and the dominance of each species. able to develop in difficult conditions (such is ultimately the winner and ❖ On February 24, 2011, the first annu- as high alcohol, nutritional depletion, high completes the fermentation due to its high al ML Wines competition was organized SO , etc.) and during aging, are responsible capacity to survive in the fermenting must. by Lallemand’s ML School. All of the 75 2 for producing negative aromatic compounds: But Brettanomyces bruxellensis is also well wines, were produced in Spain and Portugal volatile phenols (4-ethylphenol, 4-ethyl- equipped to survive the harder wine condi- and had undergone malolactic fermenta- guaiacol and 4-ethylcatechol), characterized tions (high alcohol, low pH, SO , etc.) and tion (MLF) with selected malolactic bac- 2 by animal type (horse, barnyard, etc.), phar- can multiply and produce undesirable com- teria (MLB), were tasted and evaluated maceutical (band-aid, medicine, etc.) and pounds which will affect the wine. by over 60 attendees. The winners in the ink aromas. five categories are Bodegas Itsasmendi The use of selected yeast during fermen- (), Edra Bodega y Viñedos On an international level, the volume of tation is an effective tool to control the ( Ribera del Gállego-Cinco wine affected by this defect is quite impor- population of indigenous yeast, including Villas), Bodegas Vizar (Vino de la Tierra de tant. Some studies show this defect is detec- Brettanomyces. Renouf (2006) has demons- Castilla León), Quinta Do Crastro (Douro) ted and rejected not only by professionals trated that when selected yeast is used in and Bodegas Barreda (Vino de la Tierra de but by consumers as well. For example, at wine, the population of Brettanomyces (and Castilla). The ML Wines competition was the International Wine Challenge, a wine consequently ethylphenol) is drastically organized to promote and market Spanish competition held in London, England, every reduced (Table 1). year with over 10,000 wines presented, has and Portuguese wines, and to demonstrate In addition to utilizing selected yeast, pro- consistently shown that about 13% of the the importance of controlled MLF on wine per fermentation management is important, faulty wines each year are due to exces- quality. because a stuck or sluggish fermentation sive volatile phenols – Brett contamination provides ideal conditions for the develop- (Harrop, personal communication). ment of Brettanomyces spoilage yeast. In This issue of Winemaking Update focuses WINEMAKING UPDATE the same study, Renouf (2006) shows that on various strategies to prevent the deve- the proper rehydration of the active dry Winemaking update is published by lopment of Brettanomyces, and on a new yeast was also key in microbial population Lallemand to inform oenologists and wine- method to eradicate it. management, such as to contain the proli- making staff about the latest news and 1. Proper alcoholic feration of Brettanomyces. For example, it applications arising from research. To request was shown that when a protector is used, previous issues, or to send your questions or fermentation management especially under difficult conditions, there comments, contact us at: There is a vast array of different microor- is less opportunity for a stuck or sluggish Lallemand S.A.S. ganisms that coexist in the grape/must fermentation. Consequently, the protector Sandra Escot environment. Saccharomyces yeast is often allowed the selected yeast to be in opti- 19, rue des Briquetiers dominant during fermentation, due to its mum physiological condition to dominate BP 59, 31702 Blagnac Cedex, France resistance to difficult wine conditions, but the flora and prevent the development of Tél. : (33) 5 52 74 55 55 other yeasts are also present, often microor- Brettanomyces. Natstep®, for example, is an Fax : (33) 5 52 74 55 00 ganisms that can spoil the wine, such as effective protector during yeast rehydration. [email protected] The technical information in Winemaking Spontaneous AF with a strain of selec- update is true and accurate at the time of fermentation ted yeast and specific publication. Due to the great diversity of nutrients winemaking operations, all information and Brettanomyces population 6 × 103 6 × 101 advice is provided with no guarantee or (UFC/mL) formal engagement. Lallemand products are widely available through distribution net- 4-Ethyl phenol (μg/L) 430 45 works. To find your local distributor, contact us at the above address. Table 1. Interest in utilizing a selected yeast starter and specific nutrients for better control of the microbial www.lallemandwine.com@ ecosystem. (Analyses conducted at the end of AF. Renouf 2006) Continued CELLAR REGULATED AT 18º-19ºC CELLAR REGULATED AT 14º-15ºC come with some disadvantages for the final

Controla 1 Bacteria 2 Controla Bacteria 1 Bacteria 2 product. of fungal origin, a polymer derived from the chitin in Aspergillus niger, Time required for MLF (days) 58 16 13 124 31 27 appears to be effective for significantly lowe- Volatile phenol levels (µg/L) ring Brettanomyces populations in a selective 4-ethylguaiacol 404 8 7 551 20 15 way. 4-ethylphenol 870 17 9 1119 46 32 Like starch, cellulose and collagen, chito- Average sensory analysis score (on a scale of 1 to 10) san is one of the main natural biopolymers. In fact, chitosan is already widely utilized Visual quality 5.6 6.0 6.0 6.0 5.1 5.1 for its microbial and texturing properties in Aroma quality 3.8 5.1 4.7 3.4 4.8 5.0 numerous fields, from agriculture and food, Taste quality 3.8 4.9 4.3 3.5 4.9 4.5 to medicine and cosmetology. There is now Overall quality 3.4 4.7 4.3 3.5 4.9 4.5 a chitosan of fungal origin that is both envi- ronmentally friendly (being one of the most Intensity of animal defect 3.8 0.7 0.9 4.4 0.4 1.0 widespread molecules on Earth and biode- a Not inoculated with gradable once in contact with soil) and safe Table 2. Volatile phenol production and sensory evaluation of PN2 wines at different temperatures (100% non-allergenic). The effectiveness of 2. Malolactic bacteria and Brett In a trial on a 2006 wine, chitosan for reducing and eliminating major – I was there first… the inoculation with MLB drastically reduced populations of Brettanomyces bruxellensis has the population of Brettanomyces as well as been confirmed by Aurélie Bornet (doctoral The time between the end of alcoholic fer- the levels of volatile phenols in the wines thesis 2006), as well as by many trials by mentation and the onset of malolactic fer- (Figure 1). Lallemand and its partners, such as the IOC mentation is a critical period. The wine, (Institut Oenologique de ) and not yet stabilized, is still at risk for aromatic the ICV (Institut Coopératif du Vin), which deviations. The of inocu- 800 have contributed to the development and lating the wine with MLB, or even letting a 700 660 680 validation of this product. After three years of spontaneous MLF start, can result in a win- 600 experimenting on some 40 batches totalling dow of opportunity for Brettanomyces to pro- 500 more than 6,000 hL, the dosage of 4 g/hL, liferate and produce undesirable compounds. 400 300 with 10 days of contact between the fungal- Alcoholic and co- 200 origin chitosan (called No Brett Inside™), inoculation is a procedure that has gained 100 35 5 and the wine, was validated, with successful in popularity, not only because of the time 0 treatment in 91% of cases (Figure 2). Brettanomyces Volatile phenols savings, the cost reduction for tank cooling population after MLF and, very importantly, the sensory contribu- after AF (UFC/mL) (µg/L) tion, but also because it has been shown that 10000 Non-inoculated control wine co-inoculation can help prevent the develop- 8000 Co-inoculated wine ment of Brettanomyces. A study by Gerbaux et 6000 al. (2009) has shown the potential of co- ino- 4000 culation in wines from Burgundy, Figure 1. Population of Brettanomyces and concentration of volatile phenols in 2000 France, where 50% of the Pinot Noir wines a Cabernet Franc before and after awaiting MLF contain varying amounts of MLF 0 Brettanomyces (Gerbaux 2000). The results Untreated .2 g/hL .5 g/hL .7 g/hL 1 g/hL 2 g/hL 5 g/hL (CFU/mL) (CFU/mL) Number of Brettanomyces control show that in both experimental and trials, the use of MLB limited the develop- 3. How to Treat Brett-infected Figure 2. Reducing the population of ment of Brettanomyces and the production of Brettanomyces by incrementally wine adding chitosan . Source: OIV ethylphenol and ethylguaiacol. For example, Even when all the preventive measures have proceedings, 2008. A. Bornet and a cellar experiment (Table 2) showed that in been used, there can still be an opportunity P.-L. Teisseidre. the wines produced at higher temperatures, for Brettanomyces in the finished wine, alte- the MLF was faster than those at lower tem- Indeed, the wines that were treated, in duo- ring its quality right under the nose of the peratures. Wines produced at higher tempera- trio testing, generally do not show any signi- consumer. tures, which are more conducive to bacterial ficant difference with the control wines, and growth, contained lower levels of volatile If the winemaker is faced with this challenge, when a difference is perceived the treated phenols than those produced at lower tem- some options are offered, but so far there is wine is systematically preferred. peratures. The overall quality of the wines no miracle solution. The utilization of poly- In July 2009 the Organisation Internationale produced with bacterial inoculation was not vinylpolypyrolidone (PVPP), charcoal and de la Vigne et du Vin (OIV) accepted the affected by the two cellar temperatures used, fining have shown limited results. fungal-origin chitosan as a new oenological but in all instances, the overall quality was Other techniques, such as filtration with a practice. Since December 2010, the product judged better in wines that received MLB 0.45 µm membrane, flash pasteurization, the has been accepted by European regulations. and consequently produced lower levels of utilization of (DMDC) volatile phenols. or high levels of SO2 are known. But they all

To summarize... Brettanomyces is a serious problem for wine quality. It has been clearly shown it is an important and that consumers are sensitive to it. There are many options for the winemaker to control Brettanomyces. The first involves cellar hygiene, but beyond that, fermentation mana- gement, both alcoholic and malolactic, are key. The utilization of selected yeast, at a proper dose of 25 g/hL, and of a protectant (Natstep®) at 30 g/hL during rehydration, plus proper fermentation management with appropriate nutrition, are all essential. The proper yeast choice and its characterization by our R&D team allow us to recommend the best fermentation management strategy. Malolactic fermentation is an essential step to not only stabilize the wine, but to modulate its aroma profile as well. Co-inoculation or rapid post-fermentation inoculation with malolac- tic bacteria is proven to control Brettanomyces development, and allows the full potential of the MLB to be expressed with an appropriate sensory profile. When all other precautions fail, current OIV/European regulations have approved the No Brett Inside™ chitosan product as an effective tool to stop Brettanomyces contamination. For more information on these topics, please contact your Lallemand representative.