Must volume

[distancerunner]

Is there a rule of thumb to estimating the must volume from gross weight of the lugs?

 

[CDrew]

For me, very loose approximations:

100 pounds of grapes is 10 gallons of must which is 6 gallons of wine.,

 

[distancerunner]

Loose approximations are good. Making sure we have enough volume in our fermenters.

 

[wood1954]

It will vary with variety, my Marquette yielded 36 gallons of must from 390 lbs of grapes. Close to ac10:1 ratio

 

[distancerunner]

Follow up question:

When estimating amount of additives (nutrients, enzymes, etc.) per liter/gallon, do you think in terms of the volmume of finished wine or the volume of must?

 

[BarrelMonkey]

Follow up question:

When estimating amount of additives (nutrients, enzymes, etc.) per liter/gallon, do you think in terms of the volmume of finished wine or the volume of must?

I think it can vary but the additions that I make (yeast nutrients, acid adjustments) are in terms of finished wine. The numbers I use are:

100lb grapes = 10.65 gal must, of which 3.75 gal = must solids
100lb grapes = 6.4 gal finished wine

 

[wood1954]

That’s a good question I’ve never found a good answer. Prior to fermentation I use the total amount of must to make my calculation, how ever I think it’s a bad idea to use must volume for adding sugar. With so2 and pectinase I think it’s good to use total must volume, same for tannin. I would like to see some. more experienced winemakers chip in on this.

 

[Ajmassa]

That’s a good question I’ve never found a good answer. Prior to fermentation I use the total amount of must to make my calculation, how ever I think it’s a bad idea to use must volume for adding sugar. With so2 and pectinase I think it’s good to use total must volume, same for tannin. I would like to see some. more experienced winemakers chip in on this.

when using the morewine guide to red winemaking (my bible) it explains all the different nutrient/yeast/acid additions possible. It specifically says whether to use must total or finished wine total for each thing.

The guide is pretty great and well written. It’s not just a step by step. It also explains all the “why’s” in a way that really helps to understand everything you’re doing.

(So you don’t have to dig thru for the answer the manual says:
yeast, nutrients, so2, enzymes(I think)- by must volume.
acid, sugar - by wine vol.
And offers suggested % of solids depending on varietal of grape)

Edit* screenshot from page 10

and @distancerunner I do just as @CDrew said. I take my pounds of grape-drop the last digit— & that’s my gal of just. 250lbs=25gal. (Aka divide by 10). I assume 60% yield but often get 70%.

 

[wood1954]

AJ, thanks for sharing, that’s very concise info.

 

[distancerunner]

In the past I've made the addtions by estimating finished wine volume. This could explain a few things, like why tannin and color extraction are not as strong as we'd like.

 

[BarrelMonkey]

In the past I've made the addtions by estimating finished wine volume. This could explain a few things, like why tannin and color extraction are not as strong as we'd like.

Me too - particularly nutrient additions. It makes sense to me that you'd use the volume of liquid rather than solid + liquid, but it seems like the morewine guide quoted by @Ajmassa uses total must volume?

 

[wood1954]

I think for most chemicals total volume makes, not for sugar. This year I added sugar based on must volume, now after this thread I think my wine is going to be too high for MLF.

 

[stickman]

For nutrients I use the estimated juice volume. It's just my opinion, but it makes the most sense to me. The typical nutrient analysis is conducted on a filtered juice sample, and any nutrient additions to the must will be exposed and dissolved in the fermenting juice during punching, mixing, pumping over etc.

 

[BarrelMonkey]

So... I asked Scott Labs for their recommendation, and the suggestion was to base it on pressed juice volume, but using a relatively high volume of 175 gal/ton. (Commercial winemakers use 150gal/ton, and home wine presses are probably closer to 130gal/ton).

Hope this helps!

 

[Rice_Guy]

To estimate based on finished wine one would have to know how much wine is lost in each racking because lost wine will contain an equal percentage of all solubles/ alcohol/ flavor. , ,,,, good answer.

For nutrients I use the estimated juice volume. It's just my opinion, but it makes the most sense to me. The typical nutrient analysis is conducted on a filtered juice sample, and any nutrient additions to the must will be exposed and dissolved in the fermenting juice during punching, mixing, pumping over etc.

 

[wood1954]

Update on my wine, I thought it would be plus15%, but the Wyeast MLB 4007 strain is
fermenting just fine