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BARREL HYGIENE

Barrel hygiene

How not to waste your wonderful woodThalès Wine Cellar Services has been involved with barrel hygiene for more than a decade in the South African Winelands. We use specialized barrel cleaning processes developed from French technologies to achieve top quality reconditioned wine barrels. The modern day emphasis is on prolonging the life of expensive barrels in order to drastically reduce production costs, as well as managing the risk associated with second hand barrels bought from a winemaker-friend. The modern winemaker therefore is aware of possible risks in the cellar environment, and should be well informed about proper barrel hygiene and maintenance as it can greatly prolong the life-time of the barrel. The primary risk associated with barrels is the fact that wine can penetrate the porous wood up to 8mm deep over time. This will mean that any microbes can also penetrate. Consequently, when the barrels are emptied and washed, the remaining wine and any residual organisms that reside within the structure present a major risk of spoilage (volatile acidity and off-flavours) and a residual build-up of other unwanted characters. The ThalèsWCS process has proven to be extremely effective in the reduction of microbial spoilage organisms (including Brettanomyces, and acetic acid bacteria), the removal of tartrates and lees from the wood pores, and the limited reduction of volatile acidity. Thales uses different techniques combining high pressure, water at different temperature, steam, ozone and safe chemicals at minimum effective concentrations. Periodically “new” cleaning techniques surface, which we evaluate on merit. One such technique is the so-called “blasting” with dry ice, a process which claims to remove wine residue and tartrate crystals from the wood surface. This process claims to consequently expose more wood surface to wine – leading to a longer life for the barrel. Blasting with dry ice is a physical method of cleaning, and as such would have benefits if the barrels are not regularly cleaned by conventional washing methods. This expensive process involves the removal of one barrel head before the dry ice is applied at very high speed. Cleaning barrels the ThalèsWCS way however, focuses on two things: physical deep cleaning of an intact barrel, as well as a cost effective microbial decontamination that greatly reduces potential risk to your wine.

Wineland Barrel Hygiene Feature (July 2011).pdf

Coopers (Wineland Sept09).pdf

TCA 'CORK' TAINT BlogOct132007 (2 of 1).jpg

Cork taint and Mouldy character in wine

It does not only come from cork!Organohalogens are a large family of chemical compounds that are regarded as wine contaminants. These contaminants are more commonly known as TCA (2,4,6 Trichloroanisoles) and give a musty or corked character to wines (referred to as “cork taint”). In many instances, the wines typically also do not have a mouldy, or dusty character evident, the wine simply has a very poor aroma and completely lack fruityness.Organohalogens comprise of phenol-derivates carrying halogen-molecules (chlorine, bromide) on different carbon atoms of the phenolic structures. Once these halogen phenols are formed, moulds convert them through the process of biomethylation into more volatile forms known as halogen anisoles. These compounds are responsible for cork taint (TCA) and mouldiness (TeCA, PCA) in wines. The use of chlorine-based chemicals and the presence of moulds due to poor cellar hygiene practices are some of the main causes for mouldiness and cork-taint in wines. Bromine contamination from wood fumigants and water treatments in the form of TBA give similar taint problems.Analytical Compounds tested:HALOANISOLES 2,4,6 - Trichloroanisole (2,4,6-TCA)2,4,6 - Tribromoanisole (2,4,6-TBA) 2,3,4,6 - Tetrachloroanisole (2,3,4,6-TeCA)Pentachloroanisole (PCA) HALOPHENOLS2,4,6 - Trichlorophenol (2,4,6-TCP)2,4,6 - Tribromophenol (2,4,6-TBP)2,3,4,6 - Tetrachlorophenol (2,3,4,6-TeCP)Pentachlorophenol (PCP)ORGANOCHLORINE LindaneApproximate sensory detection levelsThe sensory detection limits in wines for 2,4,6-TCA, 2,3,4,6-TeCA and PCA are 1-3 ng/L, 12 ng/L and >100 ng/L respectively). TBA contain a similar sensory levels as TCA.GENERALOrganohalogen compounds are volatile and are very easily transferred through air movements from one locality to another. In itself, the chlorophenols form do not hold a significant risk to the wine through contamination, because of the higher threshold value but it can be contributory to certain musty and damp smells detected in the cellar. The danger of these compounds lies in the fact that certain moulds (Penicillium, Fusarium, Geotrichum, Aspergillus spp etc.) can enzymatically convert these chlorophenols to chloroanisoles, the threshold value of which is much lower than that for the chlorophenols. 2,4,6-Tribromophenol (TBP) and other bromophenolic derivatives are widely used on plastics, polystyrene and wood as flame-retardants, as well as on wood and in paint as antifungal agents (E.g Wood fumigated by methyl-bromide can easily be a major source of contamination and result in TBA in the atmosphere). As with organochlorine compounds, the bromophenols are enzymatically converted to the more volatile bromoanisoles by the action of microflora. TBA has also been detected in water samples presumably the result of contaminated sources, storage containers and some water treatment practices. Wine contaminated by 2,4,6-TBA is characterised as being musty/mouldy, and the threshold value of 2,4,6-TBA in wine is 1-3 ng/L (Similar to TCA).Lindane, an insecticide commonly used to protect wood against borer worms, is part of the organochlorine family, and can be toxic when present in high levels. The threshold levels of Lindane in barrels are estimated at 19ng/g. In the air we use 20ng/L as a guideline although there is no official atmospheric threshold.CONCLUSIONLow levels of organohalogens are common in many wineries due to the diversity of materials used in wine production. Although these are not always immediate threat to wine quality, a low presence indicates a very low risk to be aware of and therefore this should be monitored and managed. RECOMMENDATIONSPlease be sure to continue with good practice of aeration and good cellar hygiene at all times. This will help to manage the risk of microbiological contamination and development of organohalogen contamination, specifically the anisoles from potential sources.GENERAL RECOMMENDATIONS1) It is highly recommended that all wines will be measured for organoanisoles (TCA, TeCA, TBA and PCA) prior to bottling and on bulk wine trade as a good quality control measure.2) Winery water should be tested for Organohalogens at least 2x per year as this is a major source of contamination (All cellar equipment, Barrels, lines etc)3) The atmosphere should be tested in cellar for organohalogens should be tested to determine any contamination as wine are typically produced and stored in these areas.4) Be sure to use correct cleaning chemicals in your cellar (Contact THALES WCS for recommendations)5) Paint your cellar with approved paints that have been tested for organohalogens. Thales WCS has tested and compiled a list of approved paints that are approved for use in wineries.

BRETT CONTROL Brett cells.jpg

How to manage Brett

The topic of Brettanomyces yeast spoilage is very actual and can be managed with an holistic approach.The attched file will give you practical tips and informationMake sure you test your wine for the main chemical indicators of Brett activity namely:4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG)Also always monitor the standard wine parametersVolatile Acidity (VA)Free SO2Total SO2pH
No Frame

Brett Control (Winetech 2010).pdf

SAFR J Vitic Enology 29 (2008) 128-144.pdf

BARREL HYGIENE

TCA 'CORK' TAINT

BRETT CONTROL