Whole Bunch Fermentation

[Rawshack]

Can anyone point me to some good information regarding whole bunch fermentation, especially for reds.

I've noticed a couple of wine writers use WBF and Carbonic Maceration as one and the same, and while I know the two processes are entwined, but any further information would be appreciated.

Even my trusty Halliday AWE doesn't provide all the answers

[pstarr]

Roughly, carbonic maceration (in the Beaujolais vein) means a fermentation taking place inside the pretty much intact whole berry, at least initially. A 'full' CM process is where you have a mass of fruit in a vessel like a pigeage pot, small tank etc and the fruit has not been crushed before the ferment. The settling weight of the berries themselves bust up the fruit at the bottom, releasing juice, while fermentation (natural or inocculated) goes ahead inside the berry and in the liberated juice. The CM effect of that in-berry fermentation (depending on what grape you use) can be to lift the aromatics, including some candy/confectionary/bubblegum characters.

Most carbonic maceration is less than the 'full' model. For example, you might set a crusher/destemmer to destem and not crush, giving you a high percentage of whole berries in a tank. Depending on what plunging, pumping, heading down, rack and return etc techniques you use to manage the cap, you might keep those whole berries entire for quite a bit of time in the ferment. That way, you get some CM characteristics but they don't dominate. Partial CM can give good results with lots of different grapes, including shiraz, pinot noir, tempranillo and monastrell/mataro/mourvedre.

Whole bunch as a term doesn't say one way or another if the berries remain entire to allow full or partial CM to happen. You could, for instance, do a bin or pot of whole bunches as a full or partial CM process, allowing it to crush itself a bit under it's own weight. But you can also use the 'whole bunch' term to refer to stalks and stems being included in a ferment where the fruit is crushed. For example, if you foot-tread a bin of whole-bunch shiraz (ie it hasn't been destemmed) and then let it ferment, it could be a 100% whole bunch ferment, but with no carbonic maceration.

What we've tended to do with whole bunch components in shiraz and pinot noir is hold back from crushing/destemming the volume we want for the whole bunch percentage desired (picking the best quality fruit for the whole bunches, with best lignification and resolution of the stalk/stem tannins). When the rest is crushed and/or destemmed, the whole bunches go in entire and ferment inside the berry. Slowly they soften and get broken up as part of the cap with manual plunging, but they get a bit of CM action before they are all busted. With wines like the 2008 shiraz, we did multiple, small, open ferments, with different percentages of whole bunches, plus some with wild yeasts, some inocculated with a couple of different yeasts (a burgundy yeast, a shiraz yeast) - all aiming to build up layers of flavour, aroma and texture. The degrees of CM in the whole bunch component, and the whole berries that the gentle destemmer does not break, contribute to the layers we are looking for.

So, sometimes 'whole bunch' and 'carbonic maceration' can mean the same thing, but other times different things

[Gavin Trott]

Very much a

non wine maker comment

but

I understood that Carbonic Maceration technique involved an oxygen free, or as close to it as you can, fermentation. So fermented in a closed atmosphere, or at least under as much CO2 as can be organised.

Whole Bunch fermentation is not (necessarily) in that environment, can even be in open fermenters.

But then again, what would I know!

.

[pstarr]

Yeah, full CM processes generate their own CO2, which can blanket the ferment. Can be supplemented with bottled gas and sealed lids as well.

[Rawshack]

Roughly, carbonic maceration (in the Beaujolais vein) means a fermentation taking place inside the pretty much intact whole berry, at least initially. A 'full' CM process is where you have a mass of fruit in a vessel like a pigeage pot, small tank etc and the fruit has not been crushed before the ferment. The settling weight of the berries themselves bust up the fruit at the bottom, releasing juice, while fermentation (natural or inocculated) goes ahead inside the berry and in the liberated juice. The CM effect of that in-berry fermentation (depending on what grape you use) can be to lift the aromatics, including some candy/confectionary/bubblegum characters.

Most carbonic maceration is less than the 'full' model. For example, you might set a crusher/destemmer to destem and not crush, giving you a high percentage of whole berries in a tank. Depending on what plunging, pumping, heading down, rack and return etc techniques you use to manage the cap, you might keep those whole berries entire for quite a bit of time in the ferment. That way, you get some CM characteristics but they don't dominate. Partial CM can give good results with lots of different grapes, including shiraz, pinot noir, tempranillo and monastrell/mataro/mourvedre.

Whole bunch as a term doesn't say one way or another if the berries remain entire to allow full or partial CM to happen. You could, for instance, do a bin or pot of whole bunches as a full or partial CM process, allowing it to crush itself a bit under it's own weight. But you can also use the 'whole bunch' term to refer to stalks and stems being included in a ferment where the fruit is crushed. For example, if you foot-tread a bin of whole-bunch shiraz (ie it hasn't been destemmed) and then let it ferment, it could be a 100% whole bunch ferment, but with no carbonic maceration.

What we've tended to do with whole bunch components in shiraz and pinot noir is hold back from crushing/destemming the volume we want for the whole bunch percentage desired (picking the best quality fruit for the whole bunches, with best lignification and resolution of the stalk/stem tannins). When the rest is crushed and/or destemmed, the whole bunches go in entire and ferment inside the berry. Slowly they soften and get broken up as part of the cap with manual plunging, but they get a bit of CM action before they are all busted. With wines like the 2008 shiraz, we did multiple, small, open ferments, with different percentages of whole bunches, plus some with wild yeasts, some inocculated with a couple of different yeasts (a burgundy yeast, a shiraz yeast) - all aiming to build up layers of flavour, aroma and texture. The degrees of CM in the whole bunch component, and the whole berries that the gentle destemmer does not break, contribute to the layers we are looking for.

So, sometimes 'whole bunch' and 'carbonic maceration' can mean the same thing, but other times different things

Wow. Say no more.

I thought I understood the process of CM quite well. Obviously not well enough. That sums everything up, thank you.

[Diddy]

Thought I might dig up an old thread and see if I can get any good recommendations for some locally available wines made with whole bunch fermentation?

Have found lately that I've been enjoying this style of wine and keen to explore further.

Thanks in advance!

[Rory]

As well as pstarr's clear explanation there is the following as well:

"During carbonic maceration, an anaerobic environment is created by pumping carbon dioxide into a sealed container filled with whole grape clusters. The carbon dioxide gas permeates through the grape skins and begins to stimulate fermentation at an intracellular level. The entire process takes place inside each single, intact berry. Ethanol is produced as a by-product of this process but studies have shown that other unique chemical reactions take place that have a distinctive effect on the wine."

[swirler]

If you want to taste whole bunch ferments gone mad see pre-2015 Bannockburn shiraz and pinot.

[Brucer]

I am not a fan of whole bunch.
It imparts a green character to the wine that I dont enjoy.

[Panda 9D]

I'd take a look at some of Head's Grenache and Contrarian Shiraz vintages (the percentage of whole bunch varies depending on vintage conditions) or you could spend some dough on Dujac's better wines from Burgundy. I can't imagine you'd be disappointed with either.

[Rory]

I am not a fan of whole bunch.
It imparts a green character to the wine that I dont enjoy.

No doubt, with the tannins (skins and stalk not being fully ripe), this would happen. But the best makers tend only to do it when those factors are all there, and even then to varying amounts. I doubt you could do whole bunch fermentation every vintage due to the variation of the beast.

[Cloth Ears]

Because wine resulting from carbonic maceration tends to mostly lack the structure for any sort of long-term aging, I tend to avoid it. Some whole bunch fermentation can add a fruity element to the wine that it would otherwise lack, but I tend to avoid it mostly.