Topping a barrel of wine is the act of filling empty headspace at the top of the barrel – or ullage – caused by absorption and evaporation. It is a routine procedure and is extremely critical to ensure the wine is healthy and maturing appropriately.
Wood barrels are porous and naturally absorb liquid over time. Evaporation also occurs in even the most ideal settings (stored at 55 degrees F and 80 percent relative humidity). This causes a need to top off the barrels every 4-6 weeks – a preventative but critical measure to avert wine spoilage.
Barrels can be topped off with some of the extra wine kept aside specifically for this purpose. Limiting the amount of air in the barrels helps to prevent damage to the wine, like developing oxidized notes or the potential blooming of aerobic bacteria that produce acetic acid (vinegar) and ethyl acetate (nail polish remover).
Topping time is also an ideal time to do routine chemical and sensory analysis. Checking the pH and sulfur levels is important, but we also taste and smell the wine as our noses and palates can often be even more sensitive tools for detection & quality than what the lab results tell us. Amlés’ winemakers, Philippe Melka and Maayan Koschitzky do this analysis regularly to see how well our wine is aging.