As many of you already know, at Poggio al Bosco wine is a story of tradition, experimentation and passion. Today we want to tell you the story of an instrument that has both to do with scientific experimentation from centuries ago and that’s part of our tradition: the airlock. Its origins are quite misterious, there are different theories on who invented it and when it entered in the common use of wine making. There is no doubt though that this incredible object has revolutionased the work of the wine-maker.
When we use it
At Poggio al Bosco we move the wines in new concrete vats and oak barrels. It doesn’t matter what material we chose to keep and age the wine: once the fermentation is over, our first task is to make sure that the wine is protected from air. So all of our vats and barrells are closed with airlocks once they are full. This way CO2, resulting from the fermentation, can find a way out without increasing the pressure inside the barrels (which would slow down the process of fermentation) and avoiding contact between wine and air, that will cause acidification. The concrete and stainless-steal vats, and the oak barrels are filled to the brimming point and on each is placed an airlock. In our cellar we keep several bottles of all the kinds of wines kept in the vats, to be able to fill up the wine when it shrinks with temperature drops and ensure that they are full and contact with oxigen is as limitated as possible. The least the contact of wine with air, the least the risk of oxidation. To do this we check on our vats regularly, so we keep under control both the expansion and reduction phases.
The airlock is a genius invention in its simplicity and it has three fundamental functions:
– It allows to fill up the vats without opening them, and so limiting the risk of oxygen exposition;
– By observing the first part of the instrument we can see if the wine is expanding or reducing, so if we have to add or extract some wine;
– It works as bubbler during fermentation.
How it works
The airlock is positioned in the top of the vat and we fill the wine up to the first ‘bubble’. Then a container with water is placed on top (the water is changed every 2-3 days to avoid bacterial accumulation) and a lid is placed on top. This way the gas emitted during fermentation have a way out, making the water in the airlock bubble, but the air can’t go in.
We recently read some theories that trace the invention of the airlock all the way to Leonardo da Vinci. We have not been able to find confirms of this theory (some documents report that the airlock has widely been used in winemaking process since the XIX century). To date the airlock remains one of the most extraordinary inventions for winemaking, in its simplicity. We would not be surprised to find out that its first inventor was Leonardo da Vinci, great inventor, born in Tuscany and lover of good wine. The Museum of Glass in Empoli held a show in 2012 on the relationship between wine and glass in history, focused mainly on the airlock.