True Barrel-Replacing, Oxygen Permeable Wine Maturation Vessels

• Superior Wine Results (less volatiles loss)!
• Cuts the cost of Oak Maturation by 80% PLUS!

In Flextank vessels, oxygen enters the wine by diffusion/permeation through the specially formulated polyethylene walls, driven by the difference in oxygen pressure in the atmosphere (0.18 atm.) on the outside and that inside, (almost zero). As in barrels, maturing wine continuously consumes all available oxygen as it diffuses in.

Flextank Maturation Vessels thus provide a NEAR-IDENTICAL oxygenation environment for wine maturation to the best wooden barriques and hogsheads, provided quality oak planks are also used.

Oak in plank form is MANY TIMES LESS COSTLY than oak in barrel form, per litre. Flextank vessels also cost a fraction of quality barrels per litre to buy and last much longer, 20 years or more. With smooth, wax-like walls, they are very easy to clean and don't harbour persistent yeast infection

Unlike barrels, Flextank vessels do not allow volatile wine components back out. 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. Many MEDALS & TROPHIES have been secured by Flextank users.

ABC Radio Australia interview (excellent intro.)

The Highly Versatile 'FLEXCUBE'
1,000 litre, stackable, transportable, oxygenates at barrel rates
REPLACES 4 BARRELS, GIVES SUPERIOR WINE!

'Getting Tanked' - Age 'Epicure' article by Jeni Port

The Cube: Self Draining Floor & Sump, Front Manhole for Tipping-out

Accessories and Options for Maturation Vessels

Printed Brochure Download

WHY Flextank Maturation Vessels Work Better than Barrels or MoX

Flextanks gently permeate O2 into wine over their entire surface, at barrel rates. Within the wine there is an insignificantly small dissolved oxygen (DO2) gradient driving the O2 diffusion. However, all MoX requires a concentrated O2 source needing high DO2 diffusion gradients, starting at or near oxygen-saturation.

MoX treated wine is usually REDOX compromised in a number of ways and often has a substantially reduced cellaring life. It is most often used to 'soften' lesser quality wines. The forrmation of excess acetaldehyde is a normal result of MoX, later removed by SO2 binding.

Acetaldehyde production in Flextank is no greater than in barrels and the rate of SO2 usage is the same.

SO2 content comparison, Flextank to Barrel

The slope of SO2 decline in a first fill Hogshead and the 1,000 L. Cubes are equivalent, hence O2 uptake rate is effectively the same

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

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.

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.

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

Patent applications have been filed in all of the major winegrowing countries, including USA, Europe, Canada, Australia, New Zealand & Sth America.

The primary patents have issued in Australia and New Zealand, the initial USA application has been accepted for grant & further patents are pending in all major winemaking countries