VERB:   to put in the place of another; switch seemingly equivalent items (e.g. “substitute regular barrels with flextank”)

DEFINITION 1: to use something or someone instead of another thing or person

(You can substitute oak barrels for flextank in the production of icon and ultra premium segment wine.)

DEFINITION 2: to perform the same job as another thing or to take its place

(Polymer flextank will substitute for less efficient oak barrels.)

(Definition of substitute verb from the Cambridge Advanced Learner’s Dictionary)

I am sure I have most reader’s attention now. Something in me shivered when I read on flextank Australia’s website, the bullish mantra “Barrels – a good idea 500 years ago…a great idea today –fFlextank Barrel replacement” for the first time. I am a traditionalist. I use barrels to mature wine in! How could I EVER be a representative of a product in which I do not whole heartedly believe in? This is a story of a paradigm shift…

The title of my M.Sc. thesis many moons ago was “The influence of oak and oak derived products on the evolution of red wine”, and this was somewhat part of the birth of the Coffee Pinotage 11 years ago. I realised throughout the course of the project that you can achieve great results by using staves as opposed to barrels, if certain aspects of the processing part is tweaked.

I met the flextank team last year, and became part of an incredible product, which raised my eyebrows at first…until I experienced the proof in the pudding. Before I get there, let me explain what flextank is. Wine is matured in barrels for two reasons mainly: One is the contribution of oak to the mouthfeel of the wine, and the second is the contribution to the wine’s aromatic complexity. The evolution of both is  influenced by oxygenation as a result of the porosity of the oak – which of course is not that consistent…hence barrel differences in many cases. flextank is a polyethylene polymer, which allows for the effect of oxygenation, making this process very homogenous and controlled. No barrel differences!

The lifespan of the 1000 L cube is more than 25 years, requires less manpower to move around, rack and transport, has no evaporative losses, is significantly more hygienic than older barrels, does not lose its ability to oxygenate at a controlled level like old barrels (new barrels 30-40 mg O2/L/year, old barrels <10 mg O2/L/year), is more space efficient (can be stacked 4 high) and can be reductively “battonaged” simply by using a forklift (yes, the seal is that effective). It can be used for both red and white wines, and can be used for alcoholic fermentation, malolactic fermentation and maturation. I almost forgot – it is also slightly more cost effective, although this should not even be part of the consideration for using flextank…

The proof of the pudding? I tasted over 40 wines in Australia earlier this year. The wines matured in flextank tasted (blind) fresher, fruitier, livelier and better integrated than the older barrels, and I did not pick up any difference between wines matured in flextank vs. NEW barrels.

Plus the friendlier carbon footprint…what more do you need?

Bertus Fourie is a winemaker, turned Enology lecturer and creator of the Barista coffee Pinotage.