Caught with my finger in the bung hole again. I'm checking the barrels to see how low the level of the wine is. If its too low, its time for topping.
I was reading a post from the Goosecross Cellars winery blog and it got me thinking. Topping barrels probably takes up more time and costs more money that any other activity in the winery.
Barrels that are full of wine don't stay full on their own. We have to add wine to each barrel every few weeks to avoid fill the void in the barrel caused by evaporation. The void contains air and that is the enemy of wine at the ageing stage (vinegar anyone?).
Evaporation takes about 5% of your wine away every year. Prime is in barrel for about two years. So for my production of about 700 gallons of Cabernet I can expect to lose about 70 gallons of wine. That's 348 bottles of wine never to be seen again.