Whole berries survive crush - break them?

[Ajmassa]

Decided to create a new topic so as to not hijack @stickman ‘s ‘2019 Cab’ thread.

If I remember correctly pump overs help eliminate the release of the harsher tannins. It's also my understanding the simple act of the grape being removed from the stem is enough for the enzymes and yeast to enter the grape without having to be fully crushed. I do believe you are correct though in the fermentation process weakening the skins perhaps even without enzymes.

This peaked my curiosity during my 2018 cab after seeing so many berries remain whole after crush. And I wasn’t sure if:

a. the juice inside even ferments-but I assumed it does.
b. If those whole berries really made a difference
c. if there was a difference, how to even break them?

I actually recorded a video during a punch down a while back. No real reason. Just wanted to document it. Finally have a use for it! Lol
This is a standard vigorous punchdown for me. In the video I’m kinda thinking out loud so you’ll see my thought process regarding the whole berries. Should I be doing something different to break those berries??

 

[NorCal]

I've tasted unopened whole berries that have survived fermentation and they were sweet. I assume the sugar is pressed out of them during the press process and any sugar that goes into the wine eventually ferments dry, but I suppose it could remain an insignificant amount of RS in the wine.

 

[stickman]

I've found that most of the berries will ferment internally, but sometimes there are some that don't. My vat or Brutes can be drained, so stubborn berries can be crushed at the bottom with the punch down tool if desired.

 

[Ajmassa]

I've tasted unopened whole berries that have survived fermentation and they were sweet. I assume the sugar is pressed out of them during the press process and any sugar that goes into the wine eventually ferments dry, but I suppose it could remain an insignificant amount of RS in the wine.

Interesting to know they can even possibly remain unfermented in there until broken or pressed. So do you do anything extra to break them if a higher amount of small berries make it through? Or just let it go and anticipate the pressing to take care of it?

Aside from the sugars i was thinking in terms of the skins. And color retention happens from the inside of the skin correct? So whole berries in the ferment wouldn’t give any color.

 

[Ajmassa]

I've found that most of the berries will ferment internally, but sometimes there are some that don't. My vat or Brutes can be drained, so stubborn berries can be crushed at the bottom with the punch down tool if desired.

So no ‘sledgehammering’ of the punchdown tool is necessary then?? Lol

I haven’t ever done this, but thinking as each lug goes through the crusher that little extra round of mashing could be beneficial before dumping into the fermenter.

 

[NorCal]

I set my rubber rollers on my destemmeer / crusher on the loosest setting, hoping to get some whole berry or berries that aren't completely smashed open. My desire is to extend fermentation as long as I can (more than the usual is 5-7 days) and if it takes longer to ferment because the sugar is not as accessible to the yeast, so be it. In the end, the % of grapes that make it all the way through and remain unfermented is quite small.

I know the color in the wine it comes from the pigment in the skins. You could be right on it coming from the inside of the grape, due to a protective coating on the grape skin. If you took a bunch of grapes and put them in a bowl of sugar and water for a while, I don't think it would leave behind any red color. If you did the same with that bunch of grapes that were opened up, you would have red water.

 

[CDrew]

What about the whole cluster fermentation idea? This has been huge the last few years among premium makers. I read the yeast even gets into the grape anyway. A very interesting thought that it softens the tannin of the wine.

 

[BI81]

The uncrushed berries go through a “semi-carbonic maceration”. Inside the grape intercellular fermentation is occurring as they attempt to respire and in the absence of yeast they’re using their own enzymes to break down sugar. During the process you aren’t extracting much tannin or color and the uncrushed grapes don’t ferment to dry. This is similar to the process used in Beaujolais Nouveau, only they’re in the opposite proportion, typically they crush 20% of the clusters or let the weight of the grapes crush and allow juice to begin fermentation which produces CO2 in a sealed tank that prevents oxygen from impacting the fermentation. They press at dry and end up with approx 6-7 Brix remaining from the berries that are then crushed at press, which they allow to continue to ferment to dry. The result is a fruitier, lighter, less tannic wine that is made to drink early. In your case the proportion of uncrushed berries is significantly less so I’d imagine you are still extracting a fair amount of tannin and color from the crushed berries, while maintaining some of the fruitier characters of the uncrushed berries. Sounds like a win win to me!!

 

[bshef]

I did a triple run with some Cab Franc. After the first run I had a few uncrushed berries, still some after the second run but nothing but skins and seeds at the end. I also squeezed the berries as I went along. Any discussion of the triple run is for another thread. By the way, it worked like a dream.