Over time, all barrels lose a small percentage of their contents to the atmosphere. We call this the “angel’s share.” Air will eventually seep into the resulting space inside the barrel. This puts the wine at risk of spoilage either from the air itself or from air-loving microbes. Either way, we want to keep the air out of there. That is why we periodically replace the wine that is lost. This is called topping!
Topping can be as easy as pouring wine from a bottle or pitcher into each barrel. This method is easy, but can be clumsy when you are dealing with hundreds of barrels, and the wine you are using for topping will be exposed to more air than necessary as it gets poured around. When we top our barrels at Epoch, we use a tool called a bulldog along with a racking wand, a long hose and a topping gun. In the picture you can see that the gold colored bulldog makes a tight seal on the barrel.
A green hose supplies pressurized argon gas through the bulldog to the top of the barrel, which puts the whole barrel under pressure (about 10 pounds per square inch). The pressure forces wine up through the stainless steel racking wand (since it goes all the way to the bottom of the barrel) which in turn supplies wine to the hose and topping gun. This is the same concept as how a beer tap works. With this setup, Zak can easily go down the line topping each barrel without even spilling a drop! Okay, maybe one or two.
Besides being an efficient method to top our barrels, the bulldog has another advantage. As the wine is depleted from the topping barrel, the headspace is automatically filled with inert argon gas, protecting the topping wine from air the whole time. All of this precious Epoch wine is safe thanks to Zak and his trusty bulldog. Thanks, Zak!