White Grapes and Skins

[Kraffty]

My first harvest of mystery grapes resulted in a bumper crop. My one old vine is between 15 and 20 years old but until a few years ago had been living in shadows. In the last couple of years, having removed the last tree near it and trellising it up against a 12 foot row of 4x4's, it's come to life. It's a seedless table grape of some sort, probably niagara or champagne but I'm going to make it into wine anyway. I get that I'll need to adjust acid and sugar and the finished product might be bland and better suited for blending or making a flavored wine of some type. I have about 130lbs. cleaned and in the deep freeze (still on the stems) and guessing I might end up with 8 gals or so before adjusting for acid level.

Here's my initial question: Will leaving the skins in the must for a while add to the wine in any way or will it hurt the color of the wine at all? I did use about 15lbs of these last year co-fermented with 20lbs of pineapple just crushed and in fruit bags to make 3 gals that are still aging and look slightly gold and very clear.

any shared experience appreciated.
Mike

 

[Rocky]

Kraffty, I realize it is blasphemy but I have always processed my white grapes "on the skins." Admittedly, the vast majority of wine that I make is red but I have made literally hundreds of gallons of a Zinfandel-Muscat blend which was co-fermented with both red and white skins in the must and I made Delaware wine when I lived in Rochester, New York on the skins. I still have some of the Delaware (5 or 6 bottles I think) that was made before we moved to Ohio in 1999. It has passed 15 years old and still "drinkable" (tastes a lot like a sherry) but we use it mostly in cooking. I call it my "lights out" wine because after about a glass or two, it is lights out!

 

[Turock]

Boy, those grapes sure LOOK like Niagara but they couldn't be because Niagara has seeds. If they're seedless, they're some kind of table grape. How do they taste? Most table grapes make a pretty tasteless wine. That's not saying you can't make wine from them, however.

Be sure to take the PH down to about 3.2 That will help the flavor, somewhat.

We always ferment our Niagara on the skins. Pressing and not using the skins gives you a real pale white. Doing it on the skins will give a straw or golden color, which is acceptable for a white.

We don't like to press our white because we feel fermenting on all that pulp adds complexity of flavor to the wine. We have done taste tests on using just the juice as opposed to on the whole grape and there's a definite difference. The only time you wouldn't ferment a white on the skins is for some varieties that have a brownish skin--those types should be pressed.

 

[robie]

Wow! Cutting down that tree opened the flood gates. Great crop.

I would have said don't ferment on the skins, but I have never done anything but Chardonnay and Rieslings, so those guys know much more about it than I. Take their good advice.

 

[GreginND]

Fermenting and macerating white wines with the skins is referred to as "orange wine". You can search a bit about it. Here's one interesting article:

http://www.bonappetit.com/blogsandforums/blogs/badaily/2013/01/orange-wine.html

 

[manvsvine]

It is common to crush the white grapes then let them soak on the skins for a few hours. Usually not more than 4 but 12 is not unheard of.

This is to extract aromatics from the skins but you press before the must takes on bitter tannins and character. There are even targeted enzyme products to use for this short white soak.

With a table grape a max dose of booster blanc or ar2000 will really help flavour and structure.


Alison Crowe the winemaker mag wine wizard wrote a good article about when she worked for Randal Graham at Bonny doon and his disastrous experiments with fermenting white grapes on the skins. The resulting bitter swill was sent to a distillery because they couldn't drink the tannic brown wine that resulted.

There is a reason that separating the skins and must prefermentation is standard practice 99% of the time.


Since freezing the grapes will break open the skins cells releasing flavours and tannins you'll probably want to reduce any post crush soak as much as possible , the contact while they thaw may be more than enough .

Don't forget to add 50 ppm of so2 at crush to reduce browning .

Rice hulls in the press wouldn't be a bad idea with thawed white grapes.

If it was my wine I'd stick with standard practice , especialy the first time. If the resulting wine from table grapes is lacking flavour , I'd blend in some Viognier or saviinion blanc from this falls harvest. A pail of that would help.

 

[Turock]

I generally agree with manvsvine. But working with the native North American grape is sort of different from grapes brought here from elsewhere or the hybrids. The native grapes have such a huge get in them that you have to use pectic enzyme on them if you intend to ferment the fruit--very different from some grapes where you would never think of using pectic enzyme on them because their gel pack is so small. All that gel has alot of flavor and aromatics.

The green skins of these kinds of grapes does not have a color impact,either. The tannins are light on these grapes, especially if they are eating grapes. All the native grapes seem to have little tannin--one reason we always add it when working with concord. But then. is an eating grape with no seeds native? Seems it would not be. I don't know much about the seedless grapes but seems it would be a manipulation by man. Same as seedless oranges??

I like the idea of booster blanc---something I thought about later after I posted. One year we made wine from Thompsson grapes and fermented the whole way on the fruit. Came out real nice--but low on flavor. I still favor the Niagara grape for superior flavor,when talking about native white grapes.

Be sure to do a cool ferment to retain volatiles--70-72 degrees.

 

[robie]

Make most of it the way you think it will turn out best. Make a smaller batch the other way and compare.

Let us know how it all turns out.

As far as identifying the type of grape, wonder if you could send samples of the grapes to places like the U of Arkansas, where they do lots of research and crossing of table grapes. You might freeze a small amount of the grapes and contact U of A, they just might help you out.

 

[salcoco]

Winemaker magazine had a good article on white wine on skins. Probably can find it on their website.

 

[manvsvine]

http://www.winemakermag.com/stories.../137-augsep-2013/1243-white-wine-skin-contact

here is that winemaker article
good tips

FWIW I really think the impact of freezing needs to be taken into consideration.

The winemaker article makes a good point , don't confuse cold soaking with maceration durring ferment

That last point needs underscoring: skin contact should be done before any significant amount of yeast activity kicks in. The extraction should be done by cool juice (essentially, by water), not by exploding yeast populations or in the presence of fermentation heat and rising ethanol

 

[GreginND]

Excellent article. Thanks.

 

[Kraffty]

Thanks for everyone's thoughts and help. I think splitting this into 2 or even 3 small batches makes sense, juice everything then add back the skins and pulp to 1 or 2 of the batches. I'm familiar with opti-white and FT blanc but not how, or when, to use rice hulls. I did find quite a few articles and think a shorter amount of time on the skins fits with what I have in mind. Hope to start this in about 3 weeks, I'll post pics and progress of the batchs side by side for comparison.
Mike

 

[ffemt128]

All my white muscadines I let them ferment on the skins for 4 days. I think they turned out well.

 

[manvsvine]

http://www.morewinemaking.com/public/pdf/wwhiw.pdf

More wines white wine manual offers good advice , worth a read before your batch

 

[BigH]

The WineMaker article on white wine skin contact seems to have moved. I believe the new link is

https://winemakermag.com/technique/1282-white-wine-skin-contact