Pumping Over

Pumping over is a red-wine fermentation technique in which fermenting wine is drawn from the bottom of the tank and returned over the floating cap of skins and seeds. It is also called remontage in French. Pumping over wets the cap, promotes contact between the liquid and grape solids, and helps extract colour, tannin and flavour during maceration.

How pumping over is performed

A pump draws wine from a lower outlet in the fermentation vessel and returns it to the top of the cap through a hose, spray bar or other distribution device. The winemaker controls the duration, flow rate and frequency according to the grape variety, temperature, fermentation activity and desired extraction. Some systems are designed for gentle cap wetting; others provide more vigorous circulation.

Purpose and effects

• Cap management: keeps the floating grape solids wet and evenly distributed.
• Colour extraction: promotes contact between juice and skins, helping extract anthocyanins.
• Tannin extraction: extracts tannins from skins and, depending on conditions, seeds.
• Heat distribution: helps move warm fermenting liquid through the tank.
• Fermentation management: can help maintain an even fermentation environment.

Pumping over versus punching down

Pumping over circulates the liquid over the cap. Punching down physically pushes the cap into the fermenting wine. Délestage drains the liquid and returns it over the solids. The techniques differ in intensity and extraction pattern.

Example: a winery may pump over a Cabernet Sauvignon tank once or more per day during active fermentation, adjusting the frequency to the desired extraction.

Chef’s note: more pumping over does not automatically mean better wine. Excessive extraction can create harsh tannins, so the winemaker adjusts cap management to the fruit and style.