In the first of our series about making canned wine, we start at the end. The filling. A complicated process that we were very ably assisted in by Sam Lambson. However, we approached this the same way as everything else in the business- admitting we were clueless and trying to learn as much as we could.
No matter if you choose the right can, the right lacquer and even the perfect wine to can (more on this in later blogs), it’s all wasted unless you fill those cans in the right way. Filling is so important because wine has a love hate relationship with oxygen. Some of the world’s most age worthy wines like powerful Barolos age so well precisely because of a little bit of oxygenation. Whether in barrels or bottles with corks, wines and fortified wines suited to ageing do so through slow and somewhat controlled micro-oxygenation. Corks are not completely air tight and neither are barrels, so small amounts of the wine comes into contact with oxygen which can help mellow wines, enhancing their flavour profiles, and even changing their colour.
But such micro-oxygenation is only suited to certain wines, for others, oxygen is a serious problem. That bottle of wine which you were saving for ages and then turned out to be a dud? The week-old wine in the fridge that tastes nothing like it did when you first opened it? This is largely down to too much oxidation, causing wine to turn sour, vinegary, plain awful, or all of the above.
If one was to literally just put wine into a can, this sort of over-oxidation is exactly what you would get, which is why ensuring the filling process is thought about carefully is absolutely critical to the quality of canned wine.
The first step is to dose the cans with liquid nitrogen, an inert gas, which ensures there is no oxygen present in the can. Because liquid nitrogen is much denser then air it also ‘sits’ in the cans until it is displaced by a liquid coming into the can – in our case wine. If done correctly, this step should ensure that there is no oxygen pick up so the wine should taste just as good as when we tried it straight from the vineyard. Using cans also means that the wine is completely sealed from oxygen, so until the moment you crack open that Copper Crew, it should be as fresh as ever.
Another sticking point in the filling process is pressure. An interesting fact about beer cans is that they are very hard to dent – if you have one in the fridge give it a go, hats off if you manage it. The reason is because beer’s carbonation creates high pressure inside the can, as the carbon dioxide is literally pushing out the sides of the beer can. Unless it is sparkling, wine has no such pressurization, so if the can is sealed without any pressure added, it would be very easy to dent and crumple the can. This would make all that time branding the outside of the can completely pointless, as they would look more ready for the recycling than shops.
Adding in carbon dioxide to increase the pressure seems an obvious choice but doing so will result in fizzy wine, which is a friend to nobody. This is where liquid nitrogen dosing comes back in handy. By adding it to the can at room temperature, it instantly warms and converts into a gas. As we just about remembered from GCSE physics, as a liquid changes to a gas it expands, providing the pressure needed to make our cans sturdy without much fizz or any taste altering effects. Getting the level of liquid nitrogen dosing right though is a precise science: too little and the can will easily dent, too much and when you went to open it you would get a face full of wine. Thankfully, Sam quite literally has a degree is such matters, so he knows exactly what to measure and monitor on the line, making our lives a whole lot easier. So, just like using the right wine, the right can and the right lacquer, filling is a science which needs to be thought about carefully to ensure product quality. Innovations in material science and operations have made this possible for not just wine in a can but beer, cider and cocktails, paving the way for more convenient, unspoiled and delicious canned drinks, just like The Copper Crew’s (if we do say so ourselves).