The Flextank System

Maturation Vessels

brochures

NOT Micro-oxygenation, a Fully Diffusive System

The Flextank System:

Oxygen enters the wine in a Flextank maturation vessel, by diffusion/permeation through the specially formulated polyethylene walls, driven by the difference in oxygen pressure in the atmosphere (0.2 atm.) on the outside and that inside, (almost zero). As in barrels, maturing wine continuously consumes all available oxygen as it diffuses in. Flextank vessels gently permeate oxygen from the atmosphere into the wine over their entire surface. The high diffusion surface area available to the wine volume means that ALL of the wine in the vessel is oxygen-exposed uniformly.

Three levels of oxygenation rate are available in Flextank vessels (22, 17 & 12 mg/L/yr). The mid-rate vessels are the most commonly used and match the typical oxygen uptake rate of a second-fill barrique or a new hogshead. As with barrels, they are best used ullage-free.

Flextank Maturation Vessels are well-proven to provide an oxygenation environment for wine maturation that is equivalent to or better than the best wooden barriques and hogsheads.

Superior to all Currently Available Alternatives:

As Good or Better than Barrels:

When premium Flextank oak adjuncts are used in Flextank maturation vessels, the resulting wine quality is second to none. Unlike barrels, Flextank vessels do not allow volatile wine components to evaporate away. Aroma and flavour compounds, ethanol and water remain in the wine. Final flavour is 'truer to the fruit' and no regular topping is needed. Most head to head trials against barrels have shown superior organoleptic results for wine matured in Flextank vessels.

Winemakers consistently report outstanding results from using Flextank maturation vessels and are regularly producing wines of the highest quality with them. Some recent Wine Show results and media accolades with wines made in Flextank vessels include:

• Minnow Creek Shiraz 2007, Trophy in class 10 (Dry Red, Shiraz - RRP over $25.00), McLaren Vale Wine Show 2008

• Lethbridge Wines, Que Syrah Syrah 2008 Shiraz, Trophy for Best Shiraz, Geelong Wine Show 2009

• Pagos del Moncayo, Garnacha, 2005 [Spain]; Robert Parker, 93 points

• Mount Alexander Winery, Shiraz-Cabernet 2008, Winestate magazine, 5 star rating

Better than Bubble Plume (High-Rate) MoX:

A localised bubble plume oxygen source sets up a relatively high DO2 diffusion gradient in the wine, starting at or near oxygen-saturation. The formation of excess acetaldehyde is a normal and expected result of pre-MLF MoX (the most common method), later removed by SO2 binding and potentially compromising cellaring life. Acetaldehyde production in Flextanks is no greater than in barrels and the rate of SO2 usage is virtually the same.

Better than Silicone MoX Tubes in Plastic Tanks (as-yet unproven):

First introduced in 2010 without calibration in wine or relevant trialling, this idea proposes use of a single finger-sized, ultra-high-permeability silicone membrane tube fitted into the top of a near-impermeable plastic storage tank made from common water tank polyethylene. It is hoped that such a device introduces MoX passively down the tube and through the membrane, at a constant low rate.

Industry MoX experts who have evaluated the concept, unequivocally state that the rate of diffusion of oxygen within cellared, i.e. thermally stagnant wine, is too low for a single 'point-source' silicone diffusion tube to adequately or uniformly oxygenate the wine in a static (i.e. unmixed) tank. Unmixed tanks fitted with such devices are also very likely to damage the wine by oxidation at the high-permeabilty membrane interface, in a similar way to damage at the surface of an ullaged tank.

This concept is completely different to the Flextank technology. Flextank vessels have a permeating surface area more than 500 times greater than these single tube diffusers and oxygenate the wine far more gently and uniformly. The only 'commonality' is that Flextanks are also made from polymer, which Flextank pioneered in 2003 after careful research, development and trialling.

Absolutely Taint-Free

Flextank's specially developed tank material meets US FDA requirements for food contact use, but has also been tested by a European laboratory and approved as SAFE FOR WINE & FORTIFIEDS CONTACT using the EEC food contact migration safety directives for wine and other ethanol containing liquids. These regulations are currently the most complete & relevant worldwide. Flextank material also contains no trace of migratory phenols, particularly bisphenol A.

Superior Volatiles Retention - No Topping in Flextanks

The most delicate components of wine (i.e. the fruity ethyl esters and aroma compounds) are largely lost to the atmosphere when wine is matured in oak barrels. The "wine/wood" aroma in the cellar arises from that 'stripping'. Wine held in barrels for too long becomes flabby, losing both freshness and fruitiness

Flextank Cubes do not evaporate wine volatiles. In trial after trial they consistently produce tasting panel ratings equal or superior to premium barrels.

Flextank also supplies only the very best Oak adjuncts, PLUS expert technical advice on their use!

Flextank vessels pay for themselves very quickly:

oaking costs are less than 10 cents/litre using top quality staves vs. more than $1/litre for oak in barrel form
purchase costs are about 1/3 that of new barrels per litre
no evaporative loss saves 3% to 5% of valuable wine volume per year
with an indefinitely long usable life, Flextanks do not "age out" like barrels
have much higher cellar storage density, two to three times depending on layouts
have superior hygiene, full cleaning access, sterilizable, no pores to harbour infective bugs
make superior wine, with better volatiles retention than evaporative barrels (i.e. no wine/wood aroma)
show much more consistent performance, vessel to vessel, year by year
Flextank offers a premium selection of oak adjuncts, based on results from trials and customer feedback

Easy to Rack, Easy to Clean, No Topping, Reduced Waste-water.

The gross lees level in these vessels is clearly visible, as is the fill level, making racking a simple task. HDPE is very easy to clean, tartar doesn't stick and this material doesn't stain. There is no porosity or "grain" to clog. These vessels retain their gas permeability indefinitely. The material is also sterilizable with boiling water or steam and/or sterilizing chemicals, allowing persistent bacterial or yeast infections such as brettanomyces to be removed completely for safe re-use. Substantial water savings are normal. Unlike oak barrels, these vessels do not require "wetting out". They clean out quickly and easily with a few litres of mild caustic as a rinse to decolourize them and a brief fresh water spray to flush solids out. Flextank vessels can be safely stored dry between fills. Unlike oak barrels, C-P vessels DO NOT allow internal liquid to pass through to the surface and evaporate away, so they do not require topping.

Safe Variable Capacity Operation Using "Skins"

Free surfaces in barrels or tanks allow air-oxygen to dissolve in wine at rates thousands of times greater than the rate it diffuses through solids. Even with CO2 in the head-space, there is usually still enough oxygen present, (CO2 dilutes air rather then displacing it), to cause aldehydic wine near the surface and to enable aerobic organisms to multiply on the surface, causing scum and some moulds.

Flextank maturation vessels are therefore supplied with a floating insert (dish or "Skin") which is lowered into the wine after the vessel is filled into the top chamber. This blocks almost all of the free surface, suppressing scum and bacteria.

For safe use part-filled, a full body sized "V-C Skin" will sufficiently reduce the exposed wine surface for the bulk of the wine to protect itself (with free SO2 in the wine). Most users flush the head space with CO2 when using V-C Skins. Flextank Skins have been in use for 4 vintages and work very well.

NOTE: In maturation vessels of 1,000 l. or smaller, operating part filled with a V-C "Skin" installed will require more frequent SO2 adjustment than with either full barrels or full maturation vessels. The wine will also mature more quickly. That is because the full surface of the vessel continues to pass oxygen at a fixed rate, but into a smaller volume of wine. SO2 consumption typically about doubles in that situation.

Manufactured to the Highest Standards

Manufacturing is carried out on a substantial and readily expandable scale at moulding plants in a number of locations worldwide. Flextank suppliers all have ISO 9001 certification, as well as potable water certification for the mouldings.

Flextanks 'Wine-Safe' raw materials comply with all relevant alcohol-containing food-contact safety standards in Australia, New Zealand, USA and Europe.

International Patents Pending

Flextank invented, developed, tested & introduced the first (worldwide) polythylene oxygenating and maturation tanks in 2003.
Patent applications have been filed in all of the major winegrowing countries, including USA, Europe, Canada, Australia, New Zealand & South America. The primary patents have issued in Australia and New Zealand and USA (May, 2010). Further patents are pending in all major winemaking countries