Interesting article on whole cluster fermentation

I found it weird how the article skipped one of the key elements of whole cluster fermentation: how it can be used to raise the pH of the wine.

The stems are probably the most potassium-rich part of the vine and potassium is an alkaline metal, so it changes the buffering capacity of the wine and neutralizes some acids in the wine. This way whole cluster fermentation can be used to soften up wines very high in acidity, but also should be avoided if the must is already low in acidity / high pH.

This is an interesting article, but it tends to ‘generalize’ a bit too much about ‘the effects’ of whole cluster fermentation and not enough about the ‘variability’ that exists.

I agree with Otto that one of the reasons whole cluster ferments are used in cooler areas is that you generally see a pH shift upward and a reduction in overall acidity, something that is ‘needed’ in much cooler areas.

The idea of ‘fixing color’ is an interesting one - but one that can be achieved also by adding tannin at the crusher (as many folks do) or by keeping the wine warmer or by micro-oxing the wine. And there is no way to know if this will be ‘successful’ unless you know the type and quantity of both tannins and monomeric anthocyanins you have to start with (part of my Masters Thesis).

Since 2014 (and with the majority of my 2013’s), all of my red lots have been 100% whole cluster fermentations. That said, I try to avoid the ‘partial carbonic’ concept by heavily foot stomping each 1/2 bin for at least 15 minutes when the grapes arrive, and then manually punching down from there. Depending upon the variety, I will end up with a handful of clusters that make it through the entire fermentation ‘unbroken’ but that’s not my intent.

My intent with whole cluster fermentation is to build structure in each of my wines ‘organically’ and not via blending other varieties in or putting the wines into new oak. I find that by doing what I’m doing, and by not racking my wines during elevage, there is a ‘freshness’ to them that allows me to be pouring 6 year old wines and have them still taste quite fresh, even on day 3 or 4 . . .

And for those who believe you need to only use ‘lignified’ stems, ask Jim Clendenon or Jamie Kutch or Pax Mahle about this - they’ll set you straight :slight_smile:


Lignified stems… that’s funny. Been doing wc for over 20 years and haven’t seen one yet.

Plus 1 to Todd.

In CA green stems may mean something different but in my experience, in Oregon if you aren’t cooking the ferment or adding enzymes you generally don’t have vegetal wines…

Yep, that’s been my experience as well - and as I said, all of my reds are now 100% whole cluster fermented.

The whole idea of ‘lignified stems’ is a wonderful ‘story’ but the reality is a different one :slight_smile:


I got your lignified stems right here!

I found the following here (some interesting stuff along with a commentary on lignification):

Myth #4: Whole-Cluster Wines Taste Stemmy Unless Stems Lignify
Apart from Beaujolais and a few other exceptions, whole-cluster fermentation is polarizing. There are philosophical arguments, technical arguments, and aesthetic preferences on the topic.

Some people oppose whole cluster because they believe stem-derived aromas and flavors mask, rather than reveal, terroir. Others feel prominent flavors derived from anything but grapes should be avoided. Counterarguments are that the character of stems does speak to both vintage and vineyard and that these notes add beauty and complexity to wine.

The qualitative judgements are all about those aromas and flavors. Some people enjoy them, some hate them. Some like them in moderation, or only when used with certain varieties, such as Syrah. But there are many factors that affect how stemmy and green a wine will taste. And there are some wines that exhibit aromas suggesting whole-cluster fermentation when none was used.

One frequent response to those who argue against stems is that stems that are “fully lignified” or “ripe” do not create excessively stemmy wines. Unfortunately, that too is an oversimplification.

Stems Don’t Fully Lignify
Lignification is the technical name for a stem becoming woody—brown, dry, and hard as opposed to green, sappy, and pliable. There are different parts to the stem, and they lignify at different rates. A peduncle is the stem that connects the entire bunch to the cane. Within the bunch are the rachis (the continuation of the peduncle that serves as the central stem within a bunch), lateral branches coming off the rachis within the bunch, and pedicels that connect individual grapes to the lateral branches.

Tyler Thomas, the managing director and director of winemaking for Santa Barbara’s Dierberg Vineyard and Star Lane Vineyard, has degrees in botany and plant molecular biology. He explains, “The peduncle will lignify. It usually happens pretty early in ripening. There’s a point after that when you get some lignification in the rachis, but I’ve never seen one fully brown, and your fruit is going to be very ripe if you wait for that.”

While “lignified stems” is an over-simplification, the degree to which lignification does occur can make a difference. Thomas continues, “The idea that we can’t use stems until they are fully lignified doesn’t make sense. But we may want to be below the radar on aromatics while still getting the tannins that we want.”

Many winemakers create wines that are not 100% whole cluster by blending different batches, using some made with stems and some without. A combined fermentation keeps the stems in juice much longer, and a wine made that way may be greener than one with the same proportions but made with separate fermentations.

Other Factors Matter
It’s logical that grapes with great intensity can stand up to more stem inclusion. Syrah is more powerful than Pinot Noir. Young vines are more intensely fruity but less nuanced than old vines. So, young Syrah might be harmonious with a larger proportion of stems, which will add complexity and structure without becoming overwhelming. Old-vine Pinot Noir might have the intensity to stand up to stems but, in some instances, there are so many nuances from fruit alone that stems can be a distraction.

Vintage and climate can make a difference, too. In warm years or regions, the ripeness of the fruit might want stems for added structure yet have enough intensity to not be dominated by those flavors. Clone, climate change, vigor, and viticultural techniques also impact intensity and phenolic ripeness, affecting the impact stems can have. Some vineyards never seem to make stemmy wines, even with substantial whole cluster. According to Thomas, the Syrah from Walker Vine Hill Vineyard in Russian River Valley is a prime example.

Takeaways on Stemmy Flavors
It is true that some wines featuring whole clusters smell and taste less stemmy than others. However, it’s not correct to say this is due to fully lignified stems, as that rarely, if ever, occurs. The degree to which stems have lignified does have an impact, but so do site, vintage, fruit character, winemaking, and viticultural techniques.


Thanks for sharing. This is one of those situations where there are plenty of ‘conventional wisdoms’ out there and people tend to take sides. When I worked for another winery, the head winemaker despised whole cluster ferments for he felt that they always led to green flavors and aromas. Interestingly, a decade later, he too is using anywhere from 10-25% whole cluster in many of the pinots, syrahs and grenaches that he is making.

I’m just not a fan of ‘over-simplifying’ and that’s what happens in a situation like this. I remember doing a tasting with a winemaker on this board who is known to use lots of whole clusters; he was leading a tour/tasting before he got to our group, and I overheard him talking about ‘waiting for the stems to ripen’ in order to use them. As soon as that tour was over and we started talking, he just smiled and pretty much said that that’s what people expect to hear :slight_smile:

I also remember a great interview with Jamie Kutch before one of the In Pursuit of Balance tasting where they were talking about whole cluster ferments and the question was asked whether he waited until the stems were lignified. He also smiled, and said that he was not afraid to use ‘neon green’ stems in his ferments.

The point here is that stems can be a powerful tool to add structure and complexity to wine . . . but they can, at times, detract from the ‘purity’ of the fruit - depending upon variety, clone, micro-climate, vintage, soil, oak treatment, yada yada yada . . .


It’s all about the seeds.

Here is another take on Whole Cluster from Kelli White at Guild Somm

No stems, no seeds that you don’t need,
That Pinot Noir is some bad-ass… oops, wrong topic.

Really just stopped by to say thanks for the interesting links. Very educational.

I’ve had very mixed results with whole cluster. In general it’s been very successful on my estate Syrahs. I love the extra spice and the way it tames the acid a bit. I’ve not had the best luck with Pinot a from Anderson Valley and our estate Zinfandels. I ferment in small fermentors and my peak temps rarely if ever get above 85 so I would say I “cook” my ferments. In a number of trials I’ve found an annoying “stalkiness” or green stemmy flavor that detracts from the pretty fruit. Even at 50% I’ve noticed this quality. So I cant really say weather I’m a fan or not because it seems very situational to me and not for every wine.

To further muddy the must, here is a study suggesting more seed tannins are extracted at higher ripeness:

It is, actually, all about the seeds. Poorly ripened seeds exacerbate unripe stem tannins.

for me, stemmy usually turns to potpourri with time in the cellar, atleast with burgundy. also oddly enough i can recall this past year i tasted pataille’s clos du roy 2014 twice, the first time being super stemmy and a few months later it already seemed to have calmed. either way i don’t mind this type of stemmy/stalky/green as long as there is enough fruit.