Case: Aromatic Profile Mastery

Transcription

1 Case: Aromatic Profile Mastery Summary Introduction Natural cork stopper properties Notion of aromatic profile Microbiological actions I. Cork treatments Purchase and storage of raw material Boiling and water management Autoclaving Cork stabilisation & Hydrodistillation Dearomatizing Dedicated facilities II. Components and end product analysis Organoleptic analysis Physical properties tests Treatments evolutions Certificate of conformity Summing up

2 Introduction Cork is a noble material, biosourced and biodegradable. It has been renowned worldwide and for centuries, especially in the wine industry, for its unique properties: it is elastic, waterproof, but above all non-hermetic to air, allowing wines to slowly mature thanks to oxygenation. Aromatic profile refers to all of the flavours that characterize a product. However, unlike his partner, glass, cork is not originally aromatically neutral and may have an impact on the aromas of the wine, and thus alter its taste. One of the main evils of natural cork is of course the "cork taint" caused by the occasional presence of organochlorines in the cork, also known as trichloroanisoles, or 2,4,6 TCAs. Elimination of perceptible TCAs has been a major issue for the cork industry for decades, some important investments have been and are still being carried out in this way. However, organochlorines, although the best known, are not the only factors of alteration of a wine s aromatic profile. An action on a microbiological level is relevant at every stage of the cork manufacturing process. Now, let us introduce you to the processes implemented upstream by our partner in order to provide your wines with an organoleptically neutral cork, that will ensure their creator that the wine tasted will be exactly as the one he imagined. 1

3 I. Cork treatments: preventive et curative actions To master cork organoleptic properties means first of all to master its microflora s development at all stages of production, beginning with the planting of cork trees until the arriving of the finished product on the market. To this end, preventive and curative actions are implemented, going through the necessary full integration of the upstream industry. Risk prevention Purchase and storage of the raw material The production of cork by its tree is a long process, the harvest can only be done once every nine or ten years, and many events can occur in the meantime. Our partner, by positioning himself very close to the families who own the cork tree forests and exercising an ongoing control and support ensures the sustainability of the production of quality corks. As an example, a farm located near the trees could contaminate them due to animal waste. Therefore, they have to make sure that none of these farms exists and will exist in the future. On the other hand, storing the entire amount of cork planks is a fundamental element that is supported by our partner right after the harvest, in his own 750,000 square feet storage area, integrated within the factory for an optimal monitoring and tracking. The cork then enters a long drying period in a healthy environment, on off-ground and covered piles that are naturally ventilated. Cork p iles 2

4 Boiling and water management After six months until more than a year of drying, the basal and stained corks are systematically eliminated before the planks undergo their first treatment. In large basins full of water, cork planks are being submerged for several hours for the socalled stage of overflowing boiling. Steaming water is injected in order to produce a dynamic movement causing an overflowing and therefore a continuous renewal of clean water. This process serves to actively clean the cork separating them from dust and other undesirable residues, but also to efficiently extract water-soluble substances and tannins. From a microbiological point of view, the boiling will impoverish the nutrients present in the cork to limit the development of its microflora, and therefore limit the risks of organoleptic alteration. To do so, the factory has its own water sanitation station with its dedicated engineer, which allows to get clean water for that stage of the cork treatment process, but also to permanently reject clean water in the nature after this treatment. These facilities are essential because insufficiently clean water could have no effect, or could even contaminate the cork planks. Overflowing boiling 3

5 Autoclaving This step is crucial since it is after the boiling that cork will be more fragile and likely to deteriorate on a microbial level. It will also serve to prepare and stabilize the cork for the beginning of its manufacture. Autoclaving will be done on the cork quickly after boiling in order to limit its exposure to its environment. The boards will be inserted into tanks where steam is injected for several hours at various pressures and temperatures. This is a crucial issue for the reason that it will remove almost all the remaining TCAs. This step is quite delicate and requires huge efforts of research and development for the following reasons: a too short steam treatment, not powerful enough or at a too low temperature, and TCAs are not properly eliminated. Too long, too powerful or too high temperature treatment will remove, for sure, the TCAs but can also alter the mechanical properties of cork, including its elasticity. This treatment requires even more work and attention since each batch or even each plank, as a natural product, is likely to react differently to the process. Autoclaving 4

6 Curative actions While prevention means to limit the development of the cork microflora by working on a microbiological level, curative actions relate directly to the extraction of aromatic molecules. Cork stabilization & Hydro-distillation The cork planks, after sterilization by autoclaving, will be kept a few days maximum under a germicidal atmosphere to maintain their sterility until hydrodistillation and later their manufacture. Steam being a natural solvent for haloanisoles, the hydro-distillation is used as a natural process with no use of any chemicals. By low pressure steam, the haloanisoles and other odorous molecules are gently extracted. Once again, the process depends on whether the treatment focuses on discs, pellets, or full corks because each of these products might respond differently to the treatment. This technique is considered as optional, but in our case, systematically applied for maximum safety. Dearomatization Exclusive and patented system, this technique has been developed by our partner in order to perfect the control process of natural corks aromatic profile. Cork naturally contains indeed three families of aromatic molecules: Vegetal family: herbaceous, woody, spicy notes... Conifer family: resinous notes, eucalyptus... Moss family: earthy tastes Thanks to a sophisticated process of flavour removing, cork boards used to make our corks stoppers tend now to an extremely homogeneous and neutral aromatic profile. 5

7 Storage tanks for pellets Dedicated facilities On top of all these processes, the factory owns exceptionally efficient disinfection and moisture control systems, guaranteeing optimal conditions of cork manufacture and storage throughout the transformation process. 6

8 II. Analysis Organoleptic analysis After going through the necessary treatments, corks are subject to various tests to make sure they comply with the current and strict cork products specifications, and especially those implemented by the Champagne Committee (C.I.V.C.). Sensory controls are led on each batch of natural cork discs and full corks in order to validate their characteristics, homogeneity and intensity of the aromatic profile. Regarding trichloroanisoles, or 2,4,6 TCAs, responsible for cork taint, we have implemented a specific double standard both for the discs and pellets used to make agglomerated part. The value of releasable TCAs may not exceed: 0.5 nanograms per litre for discs, 2 nanograms per litre for pellets. Given that is considered as detectable by human a quantity of 5 nanograms per litre, our standards guarantee an optimal level of TCA and an extremely low risk of cork taint. Physical properties test Very last step before shipment, our corks are measured, weighed, and their density is tested thanks to a resistance test. This analysis is carried out to assure our customers that their corks have been correctly manufactured and they will resist the pression of machines and ageing once on their bottles. You can find all this information in our certificates of conformity provided along with each delivery. 7

9 Evolution of the presence of TCAs over technological advances We clearly observe a sharp drop of the average rates of TCAs in corks discs throughout these processes developed and implemented from the 2000s. In practice and in the field, we as well as our customers have witnessed a fall in the number of cork taints, which represents a tremendous success from the profession on this scourge. 8

10 The certificate of conformity For each quality, each batch, and each delivery, a certificate of conformity is made and issued to the customer. It reports our corks technical features from the same batch and is as follows: Average DS Maximum Minimum Samples Dimensions Height (mm) 48,19 0,23 48,28 48,05 32 Diameter (mm) 30,85 0,10 30,90 30,75 32 Discs thickness (mm) 11,50 0,79 11,81 11,02 10 Chamfer ( ) 4,22 0,77 4,67 3,90 4 Physical features Weight (g) 9,48 0,32 10,04 8,86 32 Agglomerated moisture (%) 5,1 0,7 5,6 4,9 32 Discs moisture (%) 5,3 1,5 6,2 4,7 32 Torsion (min 28DaN cm) 57,3 5,0 61,0 56,0 4 Angle (min of torsion) (min 30 ) 54,5 6,0 57,0 51,0 4 Releasable 2,4,6 TCAs (ng/l) Pellets 1,4 40 g Discs 0,5 40 g Surface finishing Glue Silbione CAF (40g) Polyurethane 9

11 To sum up A sector under control from plantation of trees to end product. Dedicated, efficient, and environmentally friendly facilities. Emphasis on neutrality of the cork aromatic profile. Efficient, precise and patented treatment techniques. Complete analysis carried out by the factory as well as independent laboratories. A drop in TCA rates in the corks. 10

12 For any questions or comments, please contact: S.A.R.L LEFÈVRE Frères 134, avenue Maréchal Foch Épernay France Details: +33 (0)