Cellar hand Sikou Nikate tops barrels on the top row.
The City Winery team topped barrels on Wednesday. Topping is the process of filling barrels with wine as small amounts evaporate through the barrel.
Wooden barrels are porous, and as a result, they breathe, causing the evaporation of small amounts of wine. As wine evaporates, an increasing amount of air space opens up between the barrel and the surface of the wine. Too much air space can cause a wine to oxidize — if a wine has been excessively exposed to air during either its making or aging, the wine loses freshness and takes on a stale, old smell and taste. This is known as oxidation.
To prevent oxidation, winemakers top barrels.
Sikou Nikate cleans around the barrel bungs prior to topping.
At City Winery, we top barrels every 2-3 weeks, using the same variety of the wine being topped.
Prior to removing the bung (the stopper that closes the barrel), the City Winery team cleans around it with a sulfur-citric solution, diluted in water. This solution sanitizes the area around the bung and hole, so that bacteria doesn’t enter the barrel during the topping process.
Once the bung is removed, it is placed in a bucket of the sulfur-citric solution, where it is sanitized during the topping to safeguard against contamination. After the topping is finished, the sanitized bung is replaced.
Blogger Erica Swallow tops barrels using a pressurized keg and small light.
We use a pressurized keg and small light to top barrels. The keg is placed on a dolly and trucked around the barrel room, and the light is handy for seeing where the level of the wine is in the barrel.
The idea is to top the barrel so that the bottom of the bung touches the surface of the wine. Topping too full will cause wine loss when the bung is replaced, and topping too low will leave unnecessary air space.
It is especially important to top barrels once a wine is finished fermenting. While fermenting, carbon dioxide is created, protecting the wine from oxidation. After fermentation, though, the wine is more sensitive to oxidation, and thus winemakers should take great care to top barrels when needed.
Let us know if you have questions about topping in the comments below.