Fermentation is really starting to kick off. Now we’ve got to start thinking about the best way to manage the extraction of colour, tannin, and, flavour. In addition we have to think about how we develop the wine.

In the middle of all of this we need to look after the yeast, make sure they’re healthy, and, will be able to finish eating all the sugars, converting them to alcohol and carbon dioxide.

So our option:

  1. Pumping Over: Cycling liquid from the bottom to the top of the ferment using it to irrigate the cap of skins, keeping them wet, and, helping extract all the good stuff. Gentle.
  2. Rack & Returns: Draining off all the liquid into another vessel and then pumping it back over the top. This often helps break the cap up a bit more. Harder.
  3. Using Heading Down Boards: We don’t do this, but, it’s common practice in Australia and many other parts of he world. Actual timber boards are used to hold the cap of skins below the surface of the liquid to ensure they stay wet during the entire fermentation. Gentle.
  4. Rumbling with Air: Injecting air into the bottom of the fermenter. Resulting a carbon dioxided from fermentation that has dissolved into the wine, bubbling aggressively out of the solution and mixing the skins and liquid. This also has the benefit of adding oxygen that helps keep yeast strong and healthy. Gentle.
  5. Hand Plunging, or, Plunging with a Mechanical, or, Manual Plunger:  Using a device whether hand or machine to push the cap of skins down into the fermenting juice. Depends on depth of cap and method. Thin cap, gentle, thick cap with pneumatic plunger a littler harder.

We choose the option according to how the ferment tastes, our winemaking wisdom and experience with the fruit.

The variables for us are frequency of the cap management, length of management, eg do we pump it over for a few minutes or half an hour.

Next time we’ll talk more about temperature, it’s impact and how we introduce oxygen into ferments.

If you’ve got any questions, drop us a line in the comments and we'll get back to you.

6 Responses to “Just how do we get all the colour tannin and flavour out of our Shiraz berries? – Bathub Winemaking Project Day 7”

  1. James Deane

    Hello Paul,
    I have just viewed your video on rack and return. I am an amateur winemaker and also use a 500 litre plastic vat to ferment shiraz. It has been fitted with a 2″ valve into the bottom of the vat. My method of cap management, is to regularly punch down during the day. Viewing your video has given me the inspiration to carry out a delestage rack and return process and capture seeds when I drain the vat. I use Lalvin EC1118 yeast. The fermentation usually only lasts for three days and I have trouble keeping the temperature below 30 deg. I imagine draining the liquid into another tank for a couple of hours, would better manage my temperature control and extend the fermentation time, which also is time on the skins.
    Kind regards,
    Jim Deane

    Reply
    1. Paul Kaan
      Chief Wine Hacker

      Thanks for watching Jim. There are so many different options for managing ferments and extraction of colour, flavour, and, tannin. I’ve been fortunate enough to look at the same fruit sources in sufficient volume to look at a variety of techniques and find what works best, which of course changes every vintage! Regarding cooling. EC1118 hammers through fermentation very efficiently. It’s important to start at a reasonable temperature if the fruit is hot to begin with it’ll be all over very quickly. Cooling can be hard at small scale. I’m fortunate enought to have a cooling coil that I can pump ice cold water through to cool the must and the beginning of ferment and during ferment. Cheap alternative is lot’s of food grade plastic bottles filled with frozen water!

      Reply
  2. Jim Deane

    Hello Paul,
    I meant to ask you what are your thoughts on carrying out a delestage rack and return for cap management which will also result in a partial removal of seeds. How often should it be carried out.
    Regards,
    Jim

    Reply
    1. Paul Kaan
      Chief Wine Hacker

      Hey Jim, Seed removal really isn’t that common. It’s typically done when people are concerned that they might impart hard green tannin. I did it with or Cabernet on a gut feel more than anything else. Messing with the tannin soup in wine is complicated. If you’re seeds are rip ie brown then I really wouldn’t worry about it. I was probably over-reacting when I did it with the Cabernet. I haven’t got any scientific experience to demonstrate the exact impact. Hope that helps.

      Reply

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