Keeved sparkling cider - bottles?

[Mark Warnett]

Hi all

We have been successfully keeving cider for a few years now. We have been bottling in champagne bottles at around 1.014 SG then crown capping. I doubt we've ever seen a drop in SG to below 1.010, and a light sparkle only.

From an environmental and cost perspective we are thinking about going with a slightly lighter Mousseux bottle...560g, with a max carbonation of 9g/li. Based on my admittadly rough calcs, we should be ok for around a drop of 0.007 SG.

I would welcome comments:

1. if other producers are using this type of bottle for keeved in bottle fermentations

2. if there is an easy to apply formula for SG drop (and speed?!) to pressure?

Kind regards

Mark

 

[Claude Jolicoeur]

Le vendredi 23 mai 2025 à 05:19:16 UTC-4, Mark Warnett a écrit :

1. if other producers are using this type of bottle for keeved in bottle fermentations

I do, but this is not a commercial venture...

 

2. if there is an easy to apply formula for SG drop (and speed?!) to pressure?

Pressure in Atmospheres (ATM) will be roughly equal to the number of volumes of CO2 in solution. (A more precise formulation - but still approximate - would be: ATM = (Vols.CO2 / 0.87) - 0.5

You can have a good approximation of the number of volumes of CO2 from the SG drop by using my fermentation model on Excel - scrool to the end of this page to download it: http://www.cjoliprsf.ca/ciderhandbook.htm

What is more difficult is to predict the SG drop you will get in bottles from the conditions at bottling. I am currently working on this, from data I have accumulated since 15 years, over 120 batches from which I have notes on:

Conditions at bottling: SG, FSU (normalized for 10C), addition of sulfite, of DAP, and of yeast

Result as SG drop

I do have too much dispersion to my liking, but this is what it looks like. We have a petillant when the SG drop is between the yellow and orange horizontal lines, and a sparkling between the orange and red lines.

The black oblique line is the average, while the 2 blue lines are for a +/- 3 points of SG from the average.

The FDL factor is calculated from the conditions at bottling time (F for FSU, D for DAP, L for levure, French for yeast)

At the moment, I use the following formula:  

FDL = 0.33*FSU + 0.524*ppmDAPaddition + 0.19*ppmYeastAddition

These factors are purely empirical and were obtained by maximisation of the R2 correlation.

Ideally, this could be improved by adding effect from sulfite addition, state of clarification, and from SG at bottling time - but I am not there yet!

So if you take the conditions at bottling time, for example your FSU is 10 (note this needs to be corrected if average temperature is different from 10C), and you add 5ppm of DAP, this should give a FDL factor of 5.9 - hence in average I would get a SG drop of 5.9 points, and in 95% of cases, between 2.9 and 8.9. 

So, yes this is quite a large span, but if we look at all batches where the FDL factor was between 4 and 6, only 3 had excessive sparkle (i.e. SG drop of more than 9), and 2 didn't have enough to be considered "petillant".

For the temperature correction for FSU, I use : FSU(10C) = 10 * FSU(T) / T

    example, if you measure FSU 12 at average temperature T = 15C, 

    the formula gives : FSU(10C) = 10 * 12 / 15 = 8 for corrected (or normalized) value of FSU

Note this is work in progress... Use at your own risk! But I would welcome any comments.

[gareth chapman]

Broadly speaking 1 degree SG drop equals 0.5 vols of CO2 then I use a graph of vols of co2 against pressure in atm can't for the life of me remember where I got the data from but it seems to pretty much work.
I use 650g punted bottle for my sparkling keeved no problem on a 5 to 7  SG drop