malolactic fermentation as contribution to CO2 in package

[Adam]

Hello - Recently we have been canning still ciders with residual sugar and yeast with the end goal being a quite effervescent fully dry, somewhat yeasty cider. 

Essentially it carbonates in the can after an initial racking and is not disgorged. Results have been generally pretty tasty.

There have been a few instances where we have clearly exceeded the pressure ratings of our cans, in these cases the apparent carbonation has significantly exceeded what we would expect from a normal sugar-->Co2 conversion.

I think it is likely we have had some unintended malolactic fermentation in package contributing to our effervescence (we go very light on the S02 in package due to potential reactions with aluminum, and these cans are intentionally left unpasteurized).

I am curious if there is a standard formula for calculating the potential C02 contribution of malolactic fermentation in cider so that we can leave this open for wiggle room in future batches? Ex: if we see a 1.5g/l drop in measured malic acid in package, is there a corresponding increase in CO2 we should also expect to see?

Many thanks!

[Dick Dunn]

Adam - First thought on the excess carbonation: Received wisdom is that MLF
isn't likely to generate enough CO2 to make a significant difference in
overall carbonation. Keep in mind that MLF isn't a full boozy party of
yeast and sugar; rather it's a quiet gathering of fussy bacteria which are
choosy about what they eat and how it's presented.

Still, first, you might test to rule out (or in) the MLF, by comparing
acidity (or pH; either should help here) between your pre-canning cider
and from one of the over-carbonated cans.

The red flag to me is your saying "we go very light on SO2 in package". On
that basis, I'd be more inclined to suspect some spoilage organism. If
your cider is high enough in pH to allow MLF to start, it's also high
enough for some spoilage possibilities.

--
Dick Dunn rc...@talisman.com Hygiene, Colorado USA

[Patrick McCauley]

Sounds like it could be too much residual sugar rather than MLF. What was the gravity at canning? Also, I've found that adding yeast leads to a greater likelihood of explosive carbonation vs. just allowing the yeasts still remaining in suspension to do the work of the bottle conditioning.

Pat McCauley

--
--
Visit our website: http://www.ciderworkshop.com
 
You received this message because you are subscribed to the "Cider Workshop" Google Group.
By joining the Cider Workshop, you agree to abide by our principles. Please see http://www.ciderworkshop.com/resources_principles.html
---
You received this message because you are subscribed to the Google Groups "Cider Workshop" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cider-worksho...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/cider-workshop/18357256-f160-4e85-8a8a-4a41f79fd4e9n%40googlegroups.com.

[Johan]

"Received wisdom is that MLF  isn't likely to generate enough CO2 to make a significant difference in  overall carbonation. "

I have always  wondered this as I have had  some very vigorous MLFs that will blow a good amount of cider off from a topped barrel and generates a plenty of air lock activity for a long time as if it would start ferment again. That amount of CO2 would very likely affect somehow to bottle pressure also right? But then again I have had some evident late MLF in bottles (no added SO2) also without any visible CO2 so I really don't understand how this is possible.

-Johan

[Andrew Lea]

This is from a Cider Workshop thread in 2011.

Hope it helps.

Andrew

> 2. If my unsulphited, fully-fermented cider undergoes MLF next spring,
> does it produce enough gas to cause a danger of explosion / expulsion
> of bung (and possible spoilage if not spotted)?

Second time I have posted this reply to the same question in a week!

"This is always being asked so let's work through some figures. Assume
you had a dessert apple cider at 0.7% malic acid, that is 7 g/litre. The
relative molecular masses of malic acid and carbon dioxide are 134 and
44, so the amount of CO2 that is liberated by MLF if it all goes to
completion is 7*44/134 = 2.3 grams per litre. The saturation
concentration of CO2 is around 2 g/L so if there is no other CO2 present
the overpressure is the result of just 0.3 g/L CO2 which is barely
perceptible. If the cider is still saturated with CO2 from the yeast
fermentation, then the total CO2 is 4.3 g/L. Again at 15 degrees C this
is around about 1 bar pressure"

Wittenham Hill Cider Portal
www.cider.org.uk

On 26 May 2021, at 12:46, Johan <whyno...@gmail.com> wrote:

"Received wisdom is that MLF  isn't likely to generate enough CO2 to make a significant difference in  overall carbonation. "

--

--
Visit our website: http://www.ciderworkshop.com
 
You received this message because you are subscribed to the "Cider Workshop" Google Group.
By joining the Cider Workshop, you agree to abide by our principles. Please see http://www.ciderworkshop.com/resources_principles.html
---
You received this message because you are subscribed to the Google Groups "Cider Workshop" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cider-worksho...@googlegroups.com.

To view this discussion on the web, visit https://groups.google.com/d/msgid/cider-workshop/fa1be162-48ba-4088-9d43-c9fb14569739n%40googlegroups.com.