Weight of grapes to grape juice conversion

[milant]

I read somewhere on here that 20 lbs of grapes will yield about a gallon of grape juice or thereabouts. Does any body have a different number? Does this conversion differ based on the grape variety?
Thanks!!!!

 

[Johnd]

I read somewhere on here that 20 lbs of grapes will yield about a gallon of grape juice or thereabouts. Does any body have a different number? Does this conversion differ based on the grape variety?
Thanks!!!!

It's about right, although normally think about pounds of grapes to finished wine, and it very much depends upon the grapes as well as the growing conditions. Very small grapes have a much higher skin to liquid ration, so it takes more, big juicy grapes the opposite.

Three lugs of grapes (36#) will usually yield around 6 gallons of finished wine. If your grapes have a high BRIX and you have to add acidulated water, then you usually end up with slightly more.

 

[salcoco]

I usually use 12-15 lbs per gallon of finished wine

 

[Runningwolf]

I read somewhere on here that 20 lbs of grapes will yield about a gallon of grape juice or thereabouts. Does any body have a different number? Does this conversion differ based on the grape variety?
Thanks!!!!

There is no way anyone can say this is accurate. Each grape variety produces a different amount of juice that varies greatly. Additionally it depends on when they are harvested and the season. Another huge part of this is the person doing the pressing and the press itself.

If you are doing the same variety year to year and pressing yourself you'll have a very close idea of the volume to weight ratio.

 

[JohnT]

Roughly, 3 pounds of grapes per 750ml bottle.

So, there are 5 bottles to the gallon, so I would figure that it is more like 15 pounds to the gallon (as Dan says "give or take").

 

[Scooter68]

Bottom line seems to be..... You'll know how much it takes when you've done it....for this time around.

Seriously it does depend on so many factors. A grape on the vine longer in some conditions could lose water content but be at the same time concentrate the flavor. And the entire gamut of things that can change from variety and year to year based on weather etc.

Every number like this is really just a very rough estimate. That's what makes wine making an adventure. Even professional wineries that spend mega bucks analyzing their source grapes can have their plans changed by a weather change.

Imagine what things will be like for the vineyard and wineries this year after a number of years of drought and suddenly the abundance of moisture through the winter, how will that affect the vines when they start growing this years grapes?

 

[jburtner]

All that said there are some physical limitation issues here - The liquid weight of the grape is going to make up most of the weight of the juice product. One gallon of water weighs 8.3 LBS so we can assume that one gallon of wine is close enough to 8.3lbs and double that weight would pretty much be on the outside of the grape-skin&stem to juice tolerance while the other extreme of that tolerance - 8.3lbs skin&stem / gallon would be pretty impossible. Somewhere in the middle like 12lbs grapes-skins-stems / gal might be pretty close and if you add in some losses for racking off sediment and similar then the 12-15lbs / gallon finished?

I think using closer to 15lbs grapes / finished gallon for planning purposes would be pretty close and buy a bit extra for top up, racking, differences in pressing and other unanticipated losses.

Just get some extra so you have more wine!

Cheers!
-johann

 

[Rocky]

Many years ago when I made wine from grapes and lugs were 42 pounds, not 36, we could bank on about 3 gallons of finished wine per lug, net. That worked out to about 14 pounds per gallon of finished wine.

 

[cmason1957]

I always figure 100 lbs of grapes, stems, etc. Is going to net me about 6 gallons of wine a year later. Doesn't seem to matter much what grapes those are. And I press with a little hand press, so not incredibly hard.

 

[pkm925]

Others have already said it but ..

Your yield of juice depends on the grape and the conditions the grape was harvested under. Grape variety 'x' may yield one quantity while variety 'y' may yield something else. Weather conditions at or around harvest time also plays a role.

One important thing, especially if you are making red wine, is to have a good idea of how much 'must' you are dealing with (maybe as important as final yield) as this will effect how much stuff you need to use to aid your fermentation (initial SO2, yeast, yeast food, etc.).

from MoreWine's web site ...
100 lbs of fresh fruit
= 8 -10 gal must
= 5 - 6 gal finished wine

 

[Scooter68]

I assume that for figuring all this out the weights do not include stems - When you talk about a lug is that a lug before de-stemming?

 

[Kraffty]

I have to just assume here but I'd say stems included, and skins, and seeds, and spiders and bees.

Mike

 

[cmason1957]

I have to just assume here but I'd say stems included, and skins, and seeds, and spiders and bees.

Mike

And I would think you are absolutely correct. Stems, seeds, spiders , leaves. Whatever is in that lug.

 

[JohnT]

And I would think you are absolutely correct. Stems, seeds, spiders , leaves. Whatever is in that lug.

The weight of the stems and leaves do not amount to a whole heck of a lot. A full garbage can of stems could not amount to more than a pound of two.

 

[milant]

Thank you so very much for all the responses. I figured that there would be a lot of different answers and a lot of "well, that depends" answers. Bottom line is that I'm looking to do this for the first time (all kits up to know) and the local vineyard will sell 50lbs or 100lbs and will crush for me if I so choose. Considering that I'm geared up for 6 gallon batches, if figure I'd go with 100lbs of grapes and see what happens. Merlot most likely - we wine goes, it's a forgiving grape.

One thing is for sure - I'll have more questions for you guys and we get closer to the harvest time.
Milan