Cap Management

The Automated Punchdown

Red wine fermentation is done with crushed or whole grapes. This must contains skins, seeds, and some stems. During the fermentation, it is necessary to extract flavor and color from the skins, and other components. The major challenge with red wine fermentation is cap management. The “cap” consists of solids that float up due to the carbon dioxide generated in the fermentation. These solids clump together to form a mass on top of the fermenting wine.

The GOfermentor works with nature – instead of forcing the buoyant cap down, the liquid below the cap is pushed up. This is done by inflating the secondary chamber. This expanding chamber presses against the fermenting must in the primary chamber. The action pushes the liquid in the primary chamber up through the cap and then squeezes the cap itself, reducing its cross-section so that it breaks up.

Once the cap is squeezed, the pressure is released in the secondary chamber and chunks of cap drop back onto the liquid surface. The liquid that was forced through, has thoroughly wetted the cap, and now slowly percolates through the cap fragments back into the liquid layer below. The primary chamber then slowly resumes its original conformation as the CO2 builds up. The whole magic is done by inflating the secondary chamber as shown in the animation above.

This video shows you how to make red wine in the GOfermentor its own press.


Getting Started with GOfermentor

The single-use GOLINER is placed inside the GOBASE container. The destemmer/crusher discharge is connected by a hose to the top inlet port of the primary chamber of the GOLINER. This inlet has a standard 2” Triclamp port for easy connection.

Red wine fermentation is done with crushed grapes. This ‘must’ contains skins, seeds, and some stems…

The GOfermentor chamber can be filled with up to 1 ton of crushed grapes. The must can be sampled using a dip tube on the fill port. 

This video shows you how to cut the liner and add grapes in the GOfermentor.

Total Control

The Fermenting Process

During the course of the fermentation, the primary chamber will inflate due to the CO2 evolved in the fermentation. An electric vent valve is normally set to vent any excess CO2 through a pressure relief port, which prevents contamination. Samples can be taken at any time by attaching the sampler to the fill port.

Temperature control
Can be done with optional cooling plate
Vent air during filling
Withdraw samples without introducing air

Temperature of the fermentation is continuously monitored by a digital probe located close to the center of the primary chamber. Data can be transmitted for recording and control purposes.

A stainless-steel heat exchanger (GOcooler) can be mounted under the GOliner. An electric valve is provided to automatically regulate the circulation of cold fluid through the heat exchanger plate in order to maintain temperature.

The Age Old Punch Down Now serves as a Punch-UP!

This unique concept is only made possible by the use of flexible bag technology and is the secret to why the GOfermentor can extract so much color and flavor, even from marginal grapes.

Manual or programmed, the punch sequence consists of three steps:

Step 1:
Initiate the Punch

Initiate the punch, either manually or scheduling a timer-based autopunch. This opens the electric vent valve – venting the CO2 in the primary chamber to the atmosphere allowing the primary chamber to deflate.

Step 2:
Squeeze the Chamber

Once the primary chamber is deflated the secondary chamber is rapidly inflated using the built-in fan. This squeezes the primary chamber and it rises up. Liquid in the must is forced up through the cap and moistens it thoroughly. The secondary chamber pressure is pulsed a few times to break up the cap

Step 3:
Punch Done

The inflation fan shuts off and the secondary chamber deflates. The electric vent valve now closes and the primary chamber starts to pressurize again as the CO2 builds up. Any excess pressure is automatically vented through the pressure relief valve.

Harvest and Pressing

Crafting the Perfect Red Wine

With the GOfermentor, we use the secondary inflation chamber as a built-in bladder press. Harvest and pressing 1000 liters takes less than an hour and requires just one person. Here is how it works:

  1. Stop Punching 2 days before harvest to get clear wine below cap.
  2. Remove the Temperature probe. Remove the Vent valve. Insert the Pressing Tube to the vent fitting of the GOliner.
  3. Connect a hose from the Pressing Tube to a self-priming wine pump. Connect the pump discharge to a collection vessel  or bag.
  4. Start the pump. Clear free-run wine will flow out from the GOliner to the collection container. Any suspended seeds or stems will remain in the liner.
  5. Once free run stops, start pressing the GOliner by activating the Punch function 10 to 15 times to gently squeeze all the wine from the pomace. Then disconnect and discard the GOliner containing waste pomace.