Pressing involves straining the liquid off and then squeezing the remaining skins and seeds (called pomace) to get the remaining wine out, much in the same way you squeeze a sponge to release residual water. You can use anything from a nylon mesh bag into a food-grade bucket for smaller batches, to an actual wine press that can be purchased or rented for the day.  

Presses can be broken down into two design types: traditional ratcheting basket presses; and newer-style bladder presses:

• Traditional Basket Presses work by pressing the pommace from the top of the holding basket down by using a heavy, cast iron, ratcheting mechanism. Basket presses are affordable and time-tested, but there are a few drawbacks. During pressing they develop a pocket of juice in the center of the basket which needs to be broken up and repressed to get all of the wine out. In addition, the pressing forces required by basket presses are usually much higher than for bladder presses. As a result, it is very easy to get harsh and aggressive characteristics from over-pressing the seeds and skins. Finally, basket presses are difficult to sanitize and heavy to move around.  
   
• Bladder Presses work by expanding a bladder using household water pressure via a garden hose. Since the bladder is situated in the center of the press, the grapes are squeezed from the inside out in an even fashion, avoiding the formation of juice pockets. Bladder presses are quite gentle on the must and create a higher quality wine than basket presses. Furthermore, bladder presses don’t require any physical effort to operate, a hose will do all of the work for you. Finally, Bladder presses are easy to sanitize and lightweight enough to move around easily. The only downside to bladder presses is that they do cost more than basket presses.

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