Cider Carbonation Questions.

[Excidered]

Ok. So I am making some cider as some of you will have already gathered from my previous post. Although it is not ready to bottle yet, I am just trying to get my head around hat I will need to do to prime it when the time does come.
I have decided that I will use apple juice to prime instead of pure sugar.

Here is my logic and my calculations to get my carbonation right. PLEASE point out any errors or mistakes or anything I have completely misunderstood here.

As far as my Cell bio knowledge tells me...my apple juice will contain glucose and fructose, which are similar sugars and both readily fermentable. (correct me at any time here)

My apple juice contains 10.2g/100ml of sugar.

According to a chart I found, my cider, at the average temp is is sitting at, will already have somewhere between 0.80 and 0.90 volumes of CO2 present.
I will, to try to avoid under-carbonation, assume that I only have about 0.83 volumes CO2 present.

I aim for a final carbonation value of 2.4 volumes CO2.

I have also learned that 4g/l of sucrose, increases CO2 by 1.0 volumes.
Now, sucrose is comprised of one fructose and one glucose bonded together. f I assume that, from a ferment point of view, glucose and fructose are the same, then I could also assume that by weight, if I had say 1g sucrose, 1g fructose and 1g glucose, they would all ferment more or less to the same values. So I don't need to make any conversion here.

So, I have 0.83 volumes and want 2.4. so I need 1.57 (lets just say 1.6) volumes added during carbonation.

1.6 x 4 = 6.4g/L

So I need 6.4g of sugar per L to get my carbonation where I want it.

My batches have 4L in them, but I'm going to lose a bit of that when I rack it for bottling off of the lees. lets say I end up with 3.75L in my bottling bucket.

6.4 x 3.75 = 24g sugar all up.

So I need 24 grams all up.

24/10.2 (g/100ml in my priming juice) = 2.35

So I need 235ml of juice in the bottom of my bottling bucket to end up with enough sugar to carbonate out to 2.4 volumes of CO2.

Sorry for such a long spiel. I just wanted to make sure I had it all right and sorted so I can make the calculations I need once the time comes.
Does anyone see any issues or holes in my logic here? any input or corrections would be greatly appreciated.
Thanks heaps in advance!

 

[Excidered]

Any ideas? Have I got this right, or are there mistakes?

Thankyou.

 

[Excidered]

I have no idea what to do here. I'm coming up to when I will want to bottle soon and I have no idea what to do from a priming point of view. There doesn't seem to be anyone out there with a straightforward explanation with the maths of it all. Can anyone help me? give me some idea of how much juice you would add to this volume of cider maybe? I just need someone to read over this and verify that what I have said is correct....so that I don't screw my cider up haha.




Thankyou everyone who has read my post. And thanks in advance for any help.

 

[Airgead]

I have no idea what to do here. I'm coming up to when I will want to bottle soon and I have no idea what to do from a priming point of view. There doesn't seem to be anyone out there with a straightforward explanation with the maths of it all. Can anyone help me? give me some idea of how much juice you would add to this volume of cider maybe? I just need someone to read over this and verify that what I have said is correct....so that I don't screw my cider up haha.




Thankyou everyone who has read my post. And thanks in advance for any help.

The maths looks Ok to me but I usually let beersmith do all that for me. I'm not used to thinking anymore ;-)

You could check most of it with an online bulk priming calculator - http://webspace.webring.com/people/ms/sirl...Calculator.html

That would check your sucrose amount. Then it would just be the conversion from sucrose to juice that might cause problems. You will certainly be in the ballpark though.

Actually, why use juice for priming? Using sugar for the priming won't change the taste at all and would make the whole process easier.

Cheers
Dave

 

[Screwtop]

Your calcs seem ok hoever.......................

My apple juice contains 10.2g/100ml of sugar.

I have used juice which according to the nutritional panel contains 20g per 200ml = 100g/L or a specific gravity of 1.020 However the SG using a Hydrometer = 1.043.

This ferments down to 1.002 using dried cider yeast. Attenuation calc (OG-FG)/(OG-1) x 100 = (1.043 - 1.002)/(1.043-1)x100 = (0.041/0.043) x 100 = .953 x 100 = 95.3AA% for an ABV of around 5.4%

I have also learned that 4g/l of sucrose, increases CO2 by 1.0 volumes.
Now, sucrose is comprised of one fructose and one glucose bonded together. f I assume that, from a ferment point of view, glucose and fructose are the same, then I could also assume that by weight, if I had say 1g sucrose, 1g fructose and 1g glucose, they would all ferment more or less to the same values. So I don't need to make any conversion here.

The attenuation that your fermentation has achieved given your yeast and juice would be a good identifier of fermentability. If you are naturally carbonating using the same juice (speise method) then apply this attenuation figure when calculating carbonation.

Most priming calculators take into account the attenuation percentage of priming sugar, with Sucrose usually being around 95% and DME around 55%. Should be easy enough to calculate by subbing the AA% rate of your completed fermentation.

Check the specific gravity of your juice.

Cheers,

Screwy

 

[Excidered]

Thanks guys!

Airgead. If I end up with a sucrose figure, do you think it would be fair to assume that sucrose, being 1 glucose and 1 fructose (Incidentally, the sugars found in apple juice) would have the same value? So I could just take the value it gives me for adding sucrose, and work out how much juice I need to get that same mass of sugar in fructose and glucose?




Screwy. I started with a juice OG of 1.050 and now I'm sitting at 1.002.

So (1.050-1.002)/(1.050-1)= 0.96 or 96% So my juice's sugars are roughly 96% fermentable....is that what we are saying here?

If that were the case then I would need to take my value of 24g of sugar and multiply it by 1.04 to get enough to account for the non-fermentable part. yeah?

so I would be looking at 25 grams of sugar as opposed to 24, 25/10.2 = 245ml of juice instead of 235ml.

Am I doing this right, or have I totally missed the point here? Also, is my assumption that my cider already contains a certain amount of CO2 correct in my first post?

Thankyou very much. I really appreciate your help.

 

[wynnum1]

What size bottles are you using siphon directly to bottles and if sediment is put in a small bottles will settle out quickly.If you put juice in bottle first then 10 ml is about 1 gram just put correct number of grams for that size bottle and fill up with the cider.

 

[Screwtop]

so I would be looking at 25 grams of sugar as opposed to 24, 25/10.2 = 245ml of juice instead of 235ml.

Am I doing this right, or have I totally missed the point here? Also, is my assumption that my cider already contains a certain amount of CO2 correct in my first post?

Thankyou very much. I really appreciate your help.

Yes

Yes

Use temp to establish C02 volume

Screwy

 

[Excidered]

Brilliant. That was about as clear and concise as I could ask for.

Just to be a pain though......I talked to my cell biology lecturer today about this. When I asked him about working out the amount of glucose and fructose I would need to get the same effect as that amount of sucrose....he told me I would need to work it out on a grams per MOL basis. However, that would require me to know the ratio of Glucose to fructose in my juice. Which would take some complex analysis of the juice that I would not be capable of. HOWEVER....he also told me that he used to lecture in winemaking for a while and that a hydrometer could just be used instead. This makes much more sense to me. Is there a way (With a substitution for attenuation value) to calculate potential CO2 volumes from change in SG after juice is added?

Also. One last annoying question (thankyou for reading)...When I add my juice to the cider.....I will be increasing the volume as well.....so do I need to account for this extra volume when priming? I thought I would have to....but wouldn't that be a bit of a black hole....the more volume, the more sugar needed, the more juice added= more volume etc etc? So...do we just ignore that little extra bit of volume?

Thankyou very much for all who have read and responded.

 

[Screwtop]

Brilliant. That was about as clear and concise as I could ask for.

Just to be a pain though......I talked to my cell biology lecturer today about this. When I asked him about working out the amount of glucose and fructose I would need to get the same effect as that amount of sucrose....he told me I would need to work it out on a grams per MOL basis. However, that would require me to know the ratio of Glucose to fructose in my juice. Which would take some complex analysis of the juice that I would not be capable of. HOWEVER....he also told me that he used to lecture in winemaking for a while and that a hydrometer could just be used instead. This makes much more sense to me. Is there a way (With a substitution for attenuation value) to calculate potential CO2 volumes from change in SG after juice is added?

Also. One last annoying question (thankyou for reading)...When I add my juice to the cider.....I will be increasing the volume as well.....so do I need to account for this extra volume when priming? I thought I would have to....but wouldn't that be a bit of a black hole....the more volume, the more sugar needed, the more juice added= more volume etc etc? So...do we just ignore that little extra bit of volume?

Thankyou very much for all who have read and responded.

How much of a difference (somewhere between 2% and 4%) between sugar values is there going to be in the resulting volume of carbonation, methinks you are taking carbonation of your cider to quantum physics level. If you want to drill down to the n'th degree and use Henry's law then by all means take the time. Or you could use a priming calculator (Like this one and then replace the amount of sugar required with an amount of juice calculated at 50g/L (from the 1.050 SG of your juice). When it comes to our artform all of the calculation and exact science under the sun will get you........................... close :lol:

Cheers,

Screwy

 

[Excidered]

Hahaaa. Yes....I have always been on to try to overdo things like this. just can't help but want to understand the science and calculations behind it. When someone says "this many grams per this amount"....I have to ask why. Can't help it. But yeah, 2-4% certainly is negligible. Aaaaaaaand I have also always been one to overlook simple things like the fact (only just worked this out from your previous post) that the SG is directly related to sugars in juice. If 1050 means 50g sugar per L.... can work with that very comfortably. Then I can work it all out and check it with the SG of the primed cider before I bottle. Just for peace of mind.
Thanks heaps for your input Screwy. Greatly appreciated. Thanks for your patience and thanks for reminding me to keep it simple.

 

[Screwtop]

Hahaaa. Yes....I have always been on to try to overdo things like this. just can't help but want to understand the science and calculations behind it. When someone says "this many grams per this amount"....I have to ask why. Can't help it. But yeah, 2-4% certainly is negligible. Aaaaaaaand I have also always been one to overlook simple things like the fact (only just worked this out from your previous post) that the SG is directly related to sugars in juice. If 1050 means 50g sugar per L.... can work with that very comfortably. Then I can work it all out and check it with the SG of the primed cider before I bottle. Just for peace of mind.
Thanks heaps for your input Screwy. Greatly appreciated. Thanks for your patience and thanks for reminding me to keep it simple.

Cheers,

Screwy