Pressing White Grapes

[winemaker81]

I started the thread When to Press??? to spark a discussion regarding the why's and wherefore's of pressing red grapes.

@balatonwine asked about pressing white grapes, as the thread focused on reds. I had not considered whites, since AFAIK, white grape juice comes in plastic jugs or barrels.

The discussion on reds is already deep, so it makes sense to start a new thread to focus on whites. There's not much I can add to the discussion as I've never pressed white grapes, but it's interesting enough that I'm (hopefully) sparking a conversation.

 

[NorCal]

I make red and white every year from grapes. As of late, 90 gallons of red, 15-20 of white. With white, all the work is up front since you are destemming/crushing and then immediately pressing the grapes to yield the juice. My little wineasy, is good to around 1 bar of pressure and I found that a bladder press at 2X-3X that pressure is needed to get a reasonable yield. Also, I set my crusher wheels on the very outside measurement when crushing reds (to avoid breaking seeds), while with the white, far too many whole berries get through on the white if the wheels are on the outside setting. After press, I let the juice settle for a day, then rack the clean juice to ferment.

I have to say my yield is really not good, so there may be better practices. My share of the Viognoir (using a basket press) this year looks like this: 375 pounds of grapes, yielded 16.5 gallons of juice. I tossed 1.5 gallons of "dirty juice"; juice that would not settle out, even after being in the refrigerator for a few days. After ferment and a few rackings, I am at 14 gallons of clean white wine. So at $1 pound for grapes, the net is $5.75 cost of grapes per bottle, which is by far the most expensive wine I make.

 

[mainshipfred]

This past fall I purchased a bladder press but it was after the white harvest was over so I'll be able to compare the yield this fall. I'm also going to order rice hulls to help with the extraction. The wineries around here use enzymes when crushing whites but turn around and immediately press. I just don't understand how the enzymes work that quickly.

Whites are fun as @NorCal stated because everything is done up front but the cost of grapes, the yield and the cost of juice white juice buckets makes me wonder why I started making whites with grapes. I think the extraction process for whites is similar to what we do but probably not as efficient as done commercially, reds on the other hand is a different story. I'll still do whites from grapes just because it's 100% made by me but will more than likely supplement it with a few white buckets this year.

 

[cmason1957]

I have taken to doing my whites like a friend who owns a commercial winery. Makes a much "thicker" wine. Crush the grapes after picking, adding pectic enzyme or some other enzyme product. Leave in that state for 24-48 hours, then press and my friend presses to 2 bar with his press. Mix together all, both press and free run, ferment, etc. as normal. No settling, no extra nothing. I do like the whites he ends up with better than most other whites.

 

[user 36973]

I've done my hybrid whites both ways (press immediately or allow 24hrs skin contact w/enzymes&yeast). I certainly get better yield and varietal expression by allowing the short skin contact. The color doesn't seem to be any darker with 24hrs skin time than for immediately pressing and a number of my whites last fall were quite light in color. I didn't feel the need to use pressing agents such as rice hulls when the grapes have a chance to sit.

One question I don't have the answer to is whether I'm missing out on some delicate notes in the wine that I would be able to preserve by immediately pressing. Hybrids tend to be pretty fragrant regardless but tannin and aroma will vary with vinifera.

 

[cmason1957]

Oh yes, I should adder that these are hybrid grapes I am referring to. One of them is La Crescent, unusual thing to grow as far south as Missouri. It comes out with the wonderful fruit aromas and taste one would expect.

 

[Rice_Guy]

Good insight into whites! ,,, will have to try some pectase next year.

 

[winemaker81]

Would it make sense to use both approaches? Crush and do a 1 bar press, reserving the juice. Add enzyme(s) to the pomace, let rest 24-48 hours, then press to 2 bars? Ferment separately and blend as desired?

I've never done white grapes, only juice, so my experience here is nil.

 

[cmason1957]

Would it make sense to use both approaches? Crush and do a 1 bar press, reserving the juice. Add enzyme(s) to the pomace, let rest 24-48 hours, then press to 2 bars? Ferment separately and blend as desired?

I've never done white grapes, only juice, so my experience here is nil.

Never tried that and don't know how it would work, but I would wonder if the enzymes would distribute themselves as well in a "dry" environment. I always think of the way my buddy does it as an "orange" wine. I suppose it isn't technically that, but it isn't the way most folks make a white wine. Perhaps we need a new word for it.

 

[Johnd]

Never tried that and don't know how it would work, but I would wonder if the enzymes would distribute themselves as well in a "dry" environment. I always thing of the way my buddy does it as an "orange" wine. I suppose it isn't technically that, but it isn't the way most folks make a white wine. Perhaps we need a new word for it.

I agree, if you're truly trying to make a white wine, you don't want the juice / pulp on the skins any longer than necessary. Couple days of that would make a wine tending toward the orange wines. It would pick up some additional color not characteristic of a white wine, as well as some tannins from the skins and seeds.

 

[balatonwine]

Interesting discussion.

To be honest, the idea that white wines "must" (pun intended) be processed all "up front" is... well simply one wine making style for whites.

But it is not the only way.

As already stated by others, letting even a white whine soak on the skins overnight is to consider. Even 16 hours of soaking of whites on the skins can give more juice at crush. As well as increased sugar (I have seen Brix go up by one degree in 24 hours) while giving lower acid levels. I have done both up to 24 soaking on the skins of my whites, and immediate crush and press. They do create different wines. Leaving on the skins make a more complex white wine. If you like very fruity whites, crush and press as soon as possible. Also, you need a rather cold place to soak you white grapes on the skin, as they will easily otherwise oxidize.

 

[winemaker81]

bumping the thread -- anyone else have comments on pressing white grapes?

 

[mainshipfred]

bumping the thread -- anyone else have comments on pressing white grapes?

Are you looking for anything in particular?

 

[winemaker81]

Are you looking for anything in particular?

Nope. I buy white juice. I started this thread based upon a question in a thread regarding pressing reds, as whites require different techniques.

While the subject is not currently useful to me, I may learn something, and it's entirely possible I'll get a batch of white grapes and wonder whut-in-the-heck do I do?

 

[VinesnBines]

Bumping this with reference to white grape pressing. I'm going to need to process my white hybrids. I'm thinking of letting my Traminette or at least some of my harvest soak on the skins for 48 hours. I'm considering the same for the Chardonel. Mostly this is because of space for transport this weekend. With the rains hitting the East Coast from Ian, I need to transport in my van.

Anyway, crushed grapes will take up less space than whole, hence the idea.

I will be pressing the Cayuga with no soaking on the skins. We have some skin discoloration and rot so I need to get them off skins ASAP.

Any suggestions or better ideas.

 

[mainshipfred]

Bumping this with reference to white grape pressing. I'm going to need to process my white hybrids. I'm thinking of letting my Traminette or at least some of my harvest soak on the skins for 48 hours. I'm considering the same for the Chardonel. Mostly this is because of space for transport this weekend. With the rains hitting the East Coast from Ian, I need to transport in my van.

Anyway, crushed grapes will take up less space than whole, hence the idea.

I will be pressing the Cayuga with no soaking on the skins. We have some skin discoloration and rot so I need to get them off skins ASAP.

Any suggestions or better ideas.

No doubt it will take up less space. I don't know much about these varietals or how reddish their skins may be. If there is much color my only concern might be making an orange wine. Other than that I don't see much of an issue.

 

[VinesnBines]

Thanks Fred! An orange wine might not be a bad thing. This is the year for experimentation so that may be a plan.

 

[mainshipfred]

Thanks Fred! An orange wine might not be a bad thing. This is the year for experimentation so that may be a plan.

Quite frankly I wouldn't have an issue with an orange wine either.

 

[Neb Farmer]

My small backyard vineyard Riesling usually produces around 60 pounds of grapes each year. I crush and destem them immediately after harvesting, and then run them through the bladder press at a low pressure, ( around 1.5 psi ...trying not to go over 2 psi ) I tend to get 2 or 3 gallons of free-run along with another gallon of pressed juice. Then it is allowed to rest overnight in a cool room, next day adding R-HST yeast, some Ferm K , some Lallzyme C Max to begin. After fermentation is halfway done ( usually 5 days or so ) I add a little bit of GoFerm Pro to help finish it all off.

In short, I harvest, destem and press . No extended maceration or soaking. Seems to work pretty well for a nice, dry Riesling

 

[winemaker81]

One of my mentors made orange wine every other year. His habit was to purchase 1500 lbs red this year and 1500 lbs white next year. Each was fermented on the skins, and he made a 2nd run from the pomace. His method was to drain the free run juice from the pomace (no pressing IIRC), use the free run wine volume as his metric for creating the 2nd run, then when the 2nd run was done, drain it as well. THEN he pressed the pomace hard, and distributed the "squeezin's" equally between barrels. IIRC he had two first run barrels and one second run barrel for each type, white and red (6 barrels total).

Reds were barrel aged until the next red wine was ready for barrel. Whites were bottled after a year and the barrels filled with holding solution until the next white was ready.

I'd had second run reds before then, but not whites. His wines were consistently good -- he was one of two guys that approached winemaking scientifically. Most folks would not believe his second run wines were second run, unless compared directly against the first run. This was true for both white and red.