Whole Berry ferment

[NorCal]

I'm looking for ways to improve my wine next season. I am fortunate that I have very good access to excellent fruit. A local winery, Villa Winery, took the State Fair’s Winery of the Year award. They always do well with the awards at the state and national (SF Chronicle) level.

In an interview with their winemaker, he noted that they ferment whole berries and drop the temp down, having fermentation last two weeks vs. one week that happens with crushed berries and ambient temps. Ive loosen the rubber gears on my crusher/destemmer as far as they will go, it would take some other figuring out to only go a destem and not a crush.

Would this significantly help slow down the ferment? My other thought is building an AC chilling unit that would help keep the ferment temps down.

Are either of these worth the effort?

 

[Runningwolf]

I do not believe it would be worth it for you. You want to crush grapes for fermenting. Sometime's whole clusters are pressed for whites without crushing. Cool fermentations are normally for whites and higher temps for reds.

 

[JohnT]

HMMM, I agree with Dan, but I have to say that this sounds very interesting!

The way I see it, when you ferment whole fruit you are limiting the exposure of the juice to the yeast. I would think that this would slow the fermentation as it will take time for the fruit to break down and release additional juice. My fear would be that cooling down the must would simply stall your fermentation.

Another thought I have is that you will need at least some level of crushing to give your yeast something to live off of, especially in the beginning stages of fermentation (although this might happen under the grape's own weight in the primary).

Yet another thought is that a whole berry ferment will also limit the amount of exposure of juice to skins. This very well might be made up for by the extended time you are fermenting, but I would expect a lighter colored wine.

Finally, my last concern would be how to correctly handle adjustments (PH) and nutrients? You have no idea how much juice is still trapped in the fruit. If you had to add acid, for example, and add a dose to adjust your entire run, wouldn't that simply super concentrate the free juice while leaving the juice trapped in the grapes unadjusted? Would this be a concern as far as the yeast is concerned?

Also, you need to keep in mind the difference in a cold fermented wine and a hot fermented wine. Hot fermentation (for lack of a better term) will "burn off" the more delicate fruit characteristics of the grape. Think of the difference of a classic Riesling (Fruity) and a classic Chardonnay (Hot fermented).

I have to say that this sounds very interesting indeed! I just may to a test run of 5 gal or so next year. Did this interview give specifics? Yeast used? Temp that is was chilled to? nutrient schedule? Etc?

Also, My advice is that this (for you) is an experiment. I would not make any change to your crusher that can not be reversed..

 

[sour_grapes]

Are you envisioning a form of carbonic maceration?

 

[NorCal]

Here is an excerpt from the article that caught my eye and a link to the article itself.

http://www.sacbee.com/food-drink/wine/article27422959.html

 

[LenMajdan]

This is an interesting topic, Some research has shown that if you chill Shiraz grapes after de-stemming to 4C for 4 days then ferment at 14-20 C it increases the anthocyanins. The colour extraction is improved on all reds that sit for 4 days at 4 C. If you freeze the grapes you get 52% more tannin and 50% more anthocyanins. Although its better to freeze the skins rather than the juice.

When you open the rollers most berries will go through whole but a lot won't and you still get plenty of juice to start the ferment. The whole berries start fermenting slower and within the berry creating a longer fermentation period and more interesting end product. Worth playing around with.

If you really want to make some interesting red wine then when the ferment stops cover the fermenter with plastic wrap, dribble in CO2 on a regular basis and let it sit until the last of the skins fall something like 21-23 days later. According to Jeff Cox The short chain tannins become long chain tannins and the wine is just that much better. I've been doing this for the last couple of vintages and wouldn't go back to the old method.

 

[4score]

This is an interesting topic, Some research has shown that if you chill Shiraz grapes after de-stemming to 4C for 4 days then ferment at 14-20 C it increases the anthocyanins. The colour extraction is improved on all reds that sit for 4 days at 4 C. If you freeze the grapes you get 52% more tannin and 50% more anthocyanins. Although its better to freeze the skins rather than the juice.

When you open the rollers most berries will go through whole but a lot won't and you still get plenty of juice to start the ferment. The whole berries start fermenting slower and within the berry creating a longer fermentation period and more interesting end product. Worth playing around with.

If you really want to make some interesting red wine then when the ferment stops cover the fermenter with plastic wrap, dribble in CO2 on a regular basis and let it sit until the last of the skins fall something like 21-23 days later. According to Jeff Cox The short chain tannins become long chain tannins and the wine is just that much better. I've been doing this for the last couple of vintages and wouldn't go back to the old method.

Interesting. How are you adding CO2 to the primary? So, is the wine more tannic tasting/feeling? Some people like their tannin at a "respectable" limit and too much can turn them off. Perhaps this isn't a good strategy if you're after a fruit forward, average tannin, wine?

 

[LenMajdan]

The post ferment soak creates longer tannin chains which are softer. It is ready to drink even though it will also age well (I hope).
I use our kitchen SodaStream with a small plastic tube and give it a couple of blasts once a day. Jeff Cox says buy a CO2 cylinder (that is the expensive part) and set it on the lowest setting for continuous gas. The gas refill cost is low. The plastic cover and daily blasts worked ok for me.
My wife likes a fruit forward style and she says it is magic meaning balanced.