Less than 30 bottles out of a 30 bottle wine kit - got me thinking about loss of mass/volume due to C02 release during fermentation

[SatchIce9]

Today I've been bottling a 'Magnum Medium-Dry White' 30 bottle wine kit I've made (cheap kit, but I'm just getting back into the hobby), and I got 27 full 0.75 litre bottles out of it (20.25 litres), plus a partially filled bottle of only about 100ml of clear wine (total = 20.35 litres). I also poured the wine that had got cloudy and stirred up from the sediment at the bottom of my Hambleton Bard 5-gallon plastic fermenter during syphoning into a glass demijon to clear again in the hope that I can eke out a bit more from it. The liquid in the demijon is about 1.2 litres, of which I think I'll get about 700-800ml more clear wine out of when the sediment settles, which should make it 28 bottles in total.
The kit came as 1.7Kg can of concentrate, called for 3.5Kg of additional sugar and water to be topped up to 22.5 litre level on the level indicator on my fermenter. I'm sure I went a bit over think the 22.5 litre level to about 23 or 23.5 litres because I knew of the losses due to syphoning off the sediment. So this got me wondering about why I've only got about 28 bottles out of the kit, and not 30. I did consider that the litre/gallon level indicators on my Hambleton Bard 5-gallon plastic fermenter aren't very accurate, but they are embossed into the plastic rather then screen printed on the side, so I would think they are not far off.

I also started thinking about the chemistry of the fermentation as sugar is converted to alcohol, releasing C02:-
C6H12O6 ====> 2(CH3CH2OH) + 2(CO2) + Energy (which is stored in ATP)
Sugar ====> Alcohol + Carbon dioxide gas + Energy
(Glucose) (Ethyl alcohol)
As the C02 is given off into the atmosphere through the airlock, that means mass is being lost from sugar in the must you start with, and hence the final volume of wine you get. It's a long time since I did chemistry at school, but I did try to calculate the losses using the molecuar masses of the elements involved in the above chemical equation
C-carbon = 12.01 g/mol
H-hydrogen = 1.008 g/mol
O-oxygen = 16 g/mol
By my reckoning, sugar C6H12O6 = 180.156 g/mol; alcohol 2(CH3CH2OH) = 92.136 g/mol; 2(CO2) = 88.02 g/mol. (92.136 + 88.02 = 180.156, checks out)
That means the carbon dioxide lost represents 88.02 g/mol from the 180.156 g/mol sugar, which is 48.8 % lost mass.
Lets say the total sugar in the must was 4.5 Kg (1 Kg in the 1.7 Kg tin of concentrate, plus 3.5 Kg granulated sugar added as per instruction), then 48.8% = 2.196 Kg.
Estimating 1g = 1ml, that makes about 2.196 litres of volume lost due to C02 release. That could explain why I'm only getting 28 bottles rather than 30.
The thing is, they don't warn about this in the instructions, do they? They should tell you to compensate by topping up to say the 25 litre level if you really want the 30 bottles the kit claims it produces.

Please correct my chemistry, methodology or calculations if I've got anything wrong, which I suspect I might have.

 

[SatchIce9]

Another, much simpler explanation I've thought of, is that the claimed 30 bottles from the kit doesn't actually specify the capacity of the bottles they mean. If they mean 70cl bottles rather than 75cl bottles, 30 x 70 cl = 21 litres, but 30 x 75cl = 22.5 litres, so it would be easier to produce 30 x 70cl bottles with clear wine from the kit. When I first tried winemaking in early 1990s using the equipment that my dad got from Boots the chemist in the UK, used about 2 times in the 1980s, then abandoned, the 70cl bottle seemed to be standard, so it was possible to get 6 full bottles from a 1 gallon kit. These days I don't see so many 70cl bottles, as 75cl seems to be the standard size nowadays.

 

[McMullan]

I'd take a gravity reading before pitching the yeast and dilute appropriately to meet my expectations.

 

[madscientist451]

Wine making doesn't have to be full of complicated equations. Start with quality juice or grapes and the wine practically makes itself. I never even thought about how many bottles of wine I get, it is what it is. Skip the kits and buy wine grape juice by the bucket. In my area, its cheaper and you know what you are getting. The downside is that its seasonal, the buckets are available in spring and fall only.

 

[SatchIce9]

Wine making doesn't have to be full of complicated equations. Start with quality juice or grapes and the wine practically makes itself. I never even thought about how many bottles of wine I get, it is what it is. Skip the kits and buy wine grape juice by the bucket. In my area, its cheaper and you know what you are getting. The downside is that its seasonal, the buckets are available in spring and fall only.

I agree that wine making shouldn't be full of complicated equations. I was just pondering why I only got 28 bottles from the kit and had that brainwave about volume loss due to C02 release, tried to calculate how much that might be, and thought someone else on the forum might find it interesting.

I made the kit since I've just started getting back into winemaking and I wanted to make some quick and easy cheap plonk that will be okay to drink in 4 months, to get my "cellar" started. What I really enjoy is going out in the countryside and picking fruit for free, like blackberries, elderberries and crabapples, to use to make my wine. It's too late in the year to pick get any more now though because the last time I tried picking blackerries, 3 weeks ago, the ripe looking ones were too soft and turning to mush when I tried to pull them off the bush, and elderberries have been picked over by the birds or are dried up and nasty smelling. From earlier this season though I've made 2 gallons of blackberry wine (and still got enough picked blackberries in the freezer to make another gallon), 2 gallons of elderberry, and a gallon of giner wine, all clearing at the moment, but all that will need longer maturation period.

I'll maybe look into getting grape juice by the bucket, but I'm in the north of England and there aren't any vineyards around here. They do grow grapes in the south of England though, but it does sound like it would only be economical to buy in bulk and I only have the equipment capacity to handle 5 gallons at a time. I am going to be spending more on a higher quality 30 bottle kit that has a much larger volume of grape juice to begin with, though.

 

[madscientist451]

I'll maybe look into getting grape juice by the bucket, but I'm in the north of England and there aren't any vineyards around here. T

So here in the eastern US, I can get local wine grapes, California grapes and juice and imported buckets of juice from Italy.
In the spring, I can get buckets of grape juice from Argentina and Chile. If I want to drive 5-7 hrs, I can get wine grapes and juice from the Lake Erie and Northern New York regions.
I would think someone would be importing the Italian juice into the UK, and maybe French juice as well?
I found this link wine grapes, there are likely more, perhaps a local homebrew club would know more:
https://www.cmwatermelons.com/wine-...u-GdPAaQk5_S7xZmthNNVVPQB2cmRJbcaAsvNEALw_wcB
Edit: Just found this seller:

https://uvaditalia.co.uk/
I also checked facebook marketplace in the UK and there were some offers to pick your own wine grapes for free!

https://www.facebook.com/marketplace/106043772768055/search?query=wine grapes

 

[Coffee49]

Most kits require a 6 gallon (21 Ltr.) primary fermenter, with the conversion of sugar to alchohol release through the airlock the primary stage would most likely lower the 21 Ltr. volume .25 ml. After racking properly another .75 ml. lees would be left behind. I would guess after 2nd racking lees and evaporation would take .25 ml. That 30 bottle kit is down to 28. Adding an extra 2 ltrs. of water at start up would get the 30 bottle target at bottling

 

[bwible]

The wine equipment kits most commonly sold here have a 7.5 gallon bucket you use as a fermenter and a 6 gallon carboy you rack to for clearing.

The kit instructions tell you to add the concentrate and water and then take a gravity reading to make sure its in the correct range. Then you add numbered packets when they tell you to, with things like bentonite, oak, chitosan, elderflowers or whatever the particular kit uses.

The kits we get here are bag in a box kits. They have a foil bag inside of a carboard box. I haven’t seen canned concentrate kits.

These kits do claim to make 6 gallons. A 750ml bottle is called a fifth because there are 5 of those in a gallon. So yes, I would expect to get 30 bottles. When you say “full 750ml bottle” the bottle obviously can’t be filled to the top, as you have to put a cork in it. They should be filled to the same level as a bottle of wine you buy.

I would sometimes get an occasional leak out of the bottle filler or something during bottling, but that shouldn’t waste 2 bottles.

I made the occasional box wine kit years ago, haven’t made any in years. But I do recall getting around the right number, 30 bottles. I took to kegging wine with nitrogen dispense for awhile, so when I was doing that I wasn’t counting bottles.

I used to also package some of each kit in 375ml bottles for when you only wanted a little.

 

[doug293cz]

Today I've been bottling a 'Magnum Medium-Dry White' 30 bottle wine kit I've made (cheap kit, but I'm just getting back into the hobby), and I got 27 full 0.75 litre bottles out of it (20.25 litres), plus a partially filled bottle of only about 100ml of clear wine (total = 20.35 litres). I also poured the wine that had got cloudy and stirred up from the sediment at the bottom of my Hambleton Bard 5-gallon plastic fermenter during syphoning into a glass demijon to clear again in the hope that I can eke out a bit more from it. The liquid in the demijon is about 1.2 litres, of which I think I'll get about 700-800ml more clear wine out of when the sediment settles, which should make it 28 bottles in total.
The kit came as 1.7Kg can of concentrate, called for 3.5Kg of additional sugar and water to be topped up to 22.5 litre level on the level indicator on my fermenter. I'm sure I went a bit over think the 22.5 litre level to about 23 or 23.5 litres because I knew of the losses due to syphoning off the sediment. So this got me wondering about why I've only got about 28 bottles out of the kit, and not 30. I did consider that the litre/gallon level indicators on my Hambleton Bard 5-gallon plastic fermenter aren't very accurate, but they are embossed into the plastic rather then screen printed on the side, so I would think they are not far off.

I also started thinking about the chemistry of the fermentation as sugar is converted to alcohol, releasing C02:-
C6H12O6 ====> 2(CH3CH2OH) + 2(CO2) + Energy (which is stored in ATP)
Sugar ====> Alcohol + Carbon dioxide gas + Energy
(Glucose) (Ethyl alcohol)
As the C02 is given off into the atmosphere through the airlock, that means mass is being lost from sugar in the must you start with, and hence the final volume of wine you get. It's a long time since I did chemistry at school, but I did try to calculate the losses using the molecuar masses of the elements involved in the above chemical equation
C-carbon = 12.01 g/mol
H-hydrogen = 1.008 g/mol
O-oxygen = 16 g/mol
By my reckoning, sugar C6H12O6 = 180.156 g/mol; alcohol 2(CH3CH2OH) = 92.136 g/mol; 2(CO2) = 88.02 g/mol. (92.136 + 88.02 = 180.156, checks out)
That means the carbon dioxide lost represents 88.02 g/mol from the 180.156 g/mol sugar, which is 48.8 % lost mass.
Lets say the total sugar in the must was 4.5 Kg (1 Kg in the 1.7 Kg tin of concentrate, plus 3.5 Kg granulated sugar added as per instruction), then 48.8% = 2.196 Kg.
Estimating 1g = 1ml, that makes about 2.196 litres of volume lost due to C02 release. That could explain why I'm only getting 28 bottles rather than 30.
The thing is, they don't warn about this in the instructions, do they? They should tell you to compensate by topping up to say the 25 litre level if you really want the 30 bottles the kit claims it produces.

Please correct my chemistry, methodology or calculations if I've got anything wrong, which I suspect I might have.

You have to factor in density as well as mass. Ethanol has a lower density than water, and sugar has a higher density than water. This means that it takes less mass of ethanol to take up the same volume as a larger mass of sugar. So, let's look at some numbers. We will use sucrose as the sugar, since that is the basis for the Plato scale.

We'll start with a 24°P solution of sucrose and water, which has a specific gravity of 1.1011. 1 kg of this solution contains 240 g of sucrose and 760 g of water, and has a volume of 1.0 kg / (0.9982 kg/L * 1.1011) = 0.9098 L.

The reaction for fermentation of sucrose is:

C12H22O11 + H2O → 2 C6H12O6 → 4 C2H5OH + 4 CO2​

​

The molecular wt of sucrose is 342.30 g/mol, so we have: 240 g / 342.30 g/mol = 0.7011 mol. 1 mol of sucrose produces 4 mol of ethanol, so we will get: 0.7011 * 4 = 2.8046 mol of ethanol. Ethanol has a molecular wt of 46.07, so we will end up with: 129.2 g of ethanol if we convert all of the sucrose to ethanol. We will also lose 0.7011 mol of water, or 0.7011 mol * 18.02 g/mol = 12.6 g. Our final water mass will be: 760 - 12.6 = 747.7 g.

Our final solution will have a mass of: 129.2 + 747.7 = 876.9 g, and be: 100% * 129.2 / 876.9 = 14.734 wt% ethanol (about 18.3% ABV.) The density of this ethanol/water solution will be 0.9755 kg/L = 975.5 g/L. Our final volume will then be: 876.9 g / 975.5 g/L = 0.8989 L. This compares to our starting volume of 0.9098 L.

Thus our final volume is 100% * 0.8989 / 0.9098 = 98.8% of our starting volume. With your method of only considering mass, you would calculate a final volume that is 87.7% of the starting volume. In reality there is very little volume loss during fermentation, even tho you lose a lot of CO2 mass.

Brew on

 

[SatchIce9]

You have to factor in density as well as mass. Ethanol has a lower density than water, and sugar has a higher density than water. This means that it takes less mass of ethanol to take up the same volume as a larger mass of sugar. So, let's look at some numbers. We will use sucrose as the sugar, since that is the basis for the Plato scale.

We'll start with a 24°P solution of sucrose and water, which has a specific gravity of 1.1011. 1 kg of this solution contains 240 g of sucrose and 760 g of water, and has a volume of 1.0 kg / (0.9982 kg/L * 1.1011) = 0.9098 L.

The reaction for fermentation of sucrose is:

C12H22O11 + H2O → 2 C6H12O6 → 4 C2H5OH + 4 CO2​

​

The molecular wt of sucrose is 342.30 g/mol, so we have: 240 g / 342.30 g/mol = 0.7011 mol. 1 mol of sucrose produces 4 mol of ethanol, so we will get: 0.7011 * 4 = 2.8046 mol of ethanol. Ethanol has a molecular wt of 46.07, so we will end up with: 129.2 g of ethanol if we convert all of the sucrose to ethanol. We will also lose 0.7011 mol of water, or 0.7011 mol * 18.02 g/mol = 12.6 g. Our final water mass will be: 760 - 12.6 = 747.7 g.

Our final solution will have a mass of: 129.2 + 747.7 = 876.9 g, and be: 100% * 129.2 / 876.9 = 14.734 wt% ethanol (about 18.3% ABV.) The density of this ethanol/water solution will be 0.9755 kg/L = 975.5 g/L. Our final volume will then be: 876.9 g / 975.5 g/L = 0.8989 L. This compares to our starting volume of 0.9098 L.

Thus our final volume is 100% * 0.8989 / 0.9098 = 98.8% of our starting volume. With your method of only considering mass, you would calculate a final volume that is 87.7% of the starting volume. In reality there is very little volume loss during fermentation, even tho you lose a lot of CO2 mass.

Brew on

Brilliant doug293cz. I had a feeling my way of calculating it would be inaccurate and my assumptions way off - particular in the area of the difference between mass loss due to C02 release, and how that relates to volume loss. Your excellent method showing volume loss is negligable (1.2%) explains why the instructions on kits don't need to account for it.
In the end, after filtering the last dregs off the wine and sediment I saved in a demijon and allowed to clear again, I got 28.5 bottles (21.38 litres) of clear wine. I'll just add a litre and half more extra water and a bit more sugar next time if I want exactly 30 bottles.

 

[Coffee49]

It boils down to how much lees and sediment does one wish to carry over into the 1st and 2nd racking. Late harvest Concord will leave a trail of sediment throughout the process.