Prise de mousse for sharp cider with arrested fermentation

[Courtney Meier]

Hello all,

I have a relatively sharp cider with initial MAE = 7.1 g per L that I think I have stabilized via multiple rackings at an SG of ~ 1.007 (see attached SG and FSU graphs). The initial fermentation was carried out with Lalvin D47 yeast, and I added 60 ppm SO2 after pressing, and another 50 ppm in early December when I racked to a clean carboy after the cider had cleared. Given the acidity of the initial must (I haven't measured MAE post-fermentation yet), I would like to carbonate this cider in the bottle while keeping as much sweetness as possible in order to balance the acidity. Ideally, I'd actually like to bring the acidity down a bit. To that end, it seems like I could do one of the following:

1. Blend with another cider with lower acidity before bottling, then monitor to see if additional fermentation takes place. Rack if necessary to stabilize again to retain as much sugar as possible, and once stable add 10 ppm or less of DAP at bottling to stimulate prise de mousse. Optionally add some priming sugar as well as DAP in order to achieve better sugar:acid balance. The only drawback with this approach is that I'd rather not blend since I am interested in the stand-alone flavor profiles of each batch.
2. Because the cider currently tastes a bit tart, add priming sugar to raise the SG from 0.004 to 0.006 units (8.5 - 13 g per L) and also add ~ 10 ppm DAP in order to raise the sugar:acid ratio a bit and also stimulate prise de mousse. I understand from one of Claude's posts awhile back that adding DAP at 10 ppm may lead to a SG drop of 0.004, but I have not tested how predictable this is.
3. Add priming sugar to raise the SG ~ 0.004 (8.5 g per L) and add a fraction of a packet of Lalvin 71B at bottling in order to stimulate prise de mousse and also reduce the acidity to a more desirable range (hopefully 5.5 - 6 g per L MAE). Drawbacks: I've looked around (perhaps unsuccessfully?) and haven't a clue how much of a standard 71B packet to add at bottling for a 5 gal (19 L) batch. I suspect I might want 10%-20% of the packet, but I really have no idea how much to use. Using too much might create bottle bombs and too little would probably result in no acidity reduction and very little effervescence. Has any one tried this?

Anyway, I am curious to hear what people have done for ciders like this one, and what has been successful (and delicious)! Are there other options I haven't considered?

Cheers,

Courtney

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Courtney Meier | Plant Ecologist | Cider Hobbyist | Boulder, CO

[Claude Jolicoeur]

Hello Courtney,

In general, the DAP addition method works well, but there is some variability: with some batches I get more carbonation than expected, and other times I get less (although most batches - say 80% - are right on).

Important factors that I have identified are how well the cider is stabilized and clarified at the moment of the DAP addition.

Sometimes, the cider looks very stable at low temperature, but if you'd bring it in a warmer location, the fermentation would start again - such ciders would give more carbonation than expected.

A cider that is very well clarified may give less carbonation than expected because there isn't enough viable yeast left in suspension and the DAP addition isn't sufficient to reactivate it (my explanation...)

I have tried to do some yeast counting with a microscope, and although this helps, I find the exercice somewhat difficult. Maybe my microscope (or my procedure) isn't good enough.

I also have started to experiment with micro-additions of yeast instead of / combined with DAP hoping to get a better control of the prise de mousse.

When I do this, I base my calculation on 1ppm of DAP being equivalent to 2ppm of yeast.

This is from quite simple arithmetics: yeast biomass is approximately 10% N while DAP is 20% N. In other words, 2g of yeast contains the same amount of N than 1g of DAP. Hence this is simply a relation of conservation of the N.

So, yes, addition of 10ppm of DAP generally works to induce an in-bottle fermentation that will reduce the SG by about 3 to 5 points, which is just enough to give a nice mousse. But you could replace this by 20ppm of yeast, or combine yeast with DAP, for example 5ppm of DAP + 10ppm of yeast. All of these theoretically introduce the same quantity of N in the cider.

Up to now, I seem to get more consistent results with yeast addition and with combined addition than by adding DAP only. However this is still in its early stages and I don't yet have enough results to confirm... So go ahead and experiment, and report back!

PS - what do you mean by MAE - is it Malic Acid Equivalent? I guess it would be, just I can't remember having seen it written this way before.

PPS - you are in effect a bit low on SG - if you get 5 points drop during prise de mousse, you will end-up practically dry. So yes it is probably a good idea to do some back-sweetening. For my part I usually stabilize my ciders at SG between 1.010 and 1.015 and then make appropriate additions prior to bottling.

PPPS - whatever you do, it is very important that your additions are perfectly blended before bottling, otherwise you might get bottles with quite different carbonation levels within the same batch. This is mostly critical with yeast addition as it doesn't dissolve as DAP.

Claude

[Miguel Pereda]

I have never made pris de mousse in cider and therefore I have no experience in this technique but I can think of some ideas to keep in mind to assess the success or failure of this technique.
1/ First of all we are working with a supposedly small population of yeasts and that initially must be stable in number.
2/ With the microscope we can know the number we have in suspension, less than a million/mL I think. The count would not be a difficult problem as long as the sampling was correct.
3/ But what we cannot know is the fermentation capacity of these yeasts because the carriers of their cell wall will be different according to density, alcohol etc. This is why the addition of 10 ppm does not always give the expected result.
4/ This leads me to think that, at least on a theoretical level, the addition of the right number of new yeasts alone or with DAP would be a better technique than the single addition of DAP.
I hope these thoughts help. Other opinions would help me to learn.
Greetings.
Miguel Ángel Pereda

[luis gauthier]

I've also observed something using méthode ancestrale to bottle conditon my ciders.

I ferment in a lower temperature than the average recommanded range. My unheated basement's temperature is around 10-12 deg. C in fall and  it drop down to 4-5 in the colder parts of winter. When spring arrives, temperature gradually goes up to 8 or 10 deg. in april-may.

Which such low temperatures, a standard FSU of 10 is too high and will produce a too effervescent cider. A cider with a FSU as low as 2-3 might be just perfect for a sparking cider...

I've never done any yeast count and my ciders have all cleard but may not always be 100% clarified when bottled. This element might bring some incertitude...

Le mercredi 11 mars 2020 23:37:42 UTC-4, Courtney Meier a écrit :

[Courtney Meier]

Thank you all for your thoughts - much appreciated! 

Claude, that is a good insight to simply use the N-concentration of DAP and that of yeast and then calculate the equivalent ppm for yeast. Due to the fact that yeast will be a suspension rather than a solution, I may weigh out and soak in water first, let sit for 15 min or so, and then mix thoroughly and add to the cider to bottle. Regardless, this seems like a good experiment and it would be interesting to compare yeast alone with yeast + DAP with the same theoretical ppm of N addition. Do you record the final in-bottle pressure as a way of measuring response or record qualitative observations? As long as I am going to do an experiment, I might as well use the same response variables!

As for MAE, yes, that is just my short-hand for TA (g per L, MAE). And I also agree that the SG of this one is a bit low so I will back-sweeten a little prior to adding yeast/DAP and bottling. I had been hoping to stabilize a little higher, but did not quite hit the mark. This year was my first time trying to stabilize with multiple rackings after reading your book last year, and I didn't quite manage it as anticipated for some of the batches. I have also been worried about fermentation picking up again when the temperature warms and creating potentially explosive bottles. Temps are currently ~ 14 ˚C and I may try to raise to 18 ˚C or so before I bottle or add yeast/DAP, just to be sure. Thanks for all your insights!

Cheers,
Courtney

[Claude Jolicoeur]

Le jeudi 12 mars 2020 20:44:14 UTC-4, Courtney Meier a écrit :

Do you record the final in-bottle pressure as a way of measuring response or record qualitative observations? As long as I am going to do an experiment, I might as well use the same response variables!

What I measure is the SG drop during in-bottle fermentation, using precision hydrometer. It is a pretty reliable indication of the level of carbonation. I generally aim for 4 to 5 points of gravity drop, which gives a "bel effet de mousse au service" as the French say. The "perfect" mousse is the one that would get to about 1 to 2 cm thick on service and drop down within about 20 seconds. At this level, there is generally no spill from the bottle when you open it.

If you overdo it, for example at 7 - 8 points of gravity drop, you'll have to be quick when opening, and have the glass ready to take a slight gush out of the bottle, but it is still manageable. The mousse will also be more persistant and you won't be able to fill the glass on the first pour - more like Champagne where you have to go to each glass a second time after the mousse from the first pour has fallen down...

Temps are currently ~ 14 ˚C and I may try to raise to 18 ˚C or so before I bottle or add yeast/DAP, just to be sure. Thanks for all your insights!

At 14C I wouldn't worry - this is warm enough.

To give you an idea, this year I had a batch in my fermentation room (8 to 9C) really slow at that temperature, it was going at 17 FSU while still at a SG of 1.045. I brought the carboy in a warmer room with temperature of 14-15C and the FSU went up to 68 within a few days - so the FSU was multiplied by 4 with a temperature increase of 6 degrees. I was amazed. After a few days, I brought it back to my colder room and FSU went down to 23.

On another batch, FSU had really dropped after a racking, down to 3. But I wasn't sure if it was really stable and that I could bottle it yet, so brought the carboy to the warmer room, and FSU went up to 25! Which means you can get real surprises when using FSU at a too low temperature for assessing stability. But at 14C, you are warm enough.

Claude

[luis gauthier]

PPPS - whatever you do, it is very important that your additions are perfectly blended before bottling, otherwise you might get bottles with quite different carbonation levels within the same batch. This is mostly critical with yeast addition as it doesn't dissolve as DAP.

Claude, I am wondering how you blend your yeast at botling. Do you add rehydrated yeast in the bottom of a carboy or pail in which you tranfer your cider before botling (like one would do for sugar or DAP addition) or you have another procedure?

Also, I am wondering if mixing yeast and water and using a syringe to insure a consistent amount of yeast per bottle could be an interesting approch to this problem.

Thank you,

Louis

[Claude Jolicoeur]

Le mercredi 25 mars 2020 00:38:08 UTC-4, luis gauthier a écrit :

Claude, I am wondering how you blend your yeast at botling. Do you add rehydrated yeast in the bottom of a carboy or pail in which you tranfer your cider before botling (like one would do for sugar or DAP addition) or you have another procedure?

Well, let's say I bottle a 20L batch. I first rack about 2L in a large Becher in which I mix the rehydrated yeast. Then as I rack the rest in a pail, I gradually mix in the content of the becher during the racking. Then I let sit for a while (a couple of hours). And just before filling, I will agitate the cider to insure the yeast is in suspension.

Claude

[Courtney Meier]

Hello folks,

I recorded some observations over this past year for all of my ciders that I bottle conditioned. After Claude's notes above, the questions I was interested in answering were:

1. Does bottle-conditioning with Lalvin 71B lower the acidity of the bottle-conditioned cider in any measurable way?
2. For a well-clarified cider that may lack sufficient populations of viable yeast, does bottle-conditioning with a commercial yeast as the N-source yield consistent results?
3. Can a wild-fermented cider be consistently bottle-conditioned with a commercial yeast?

All of the ciders I bottle-conditioned I thought were well-clarified and stable, and had been slowly brought up to 14 ˚C before bottling as spring-time temperatures in the basement slowly increased. It is not a full-factorial crossed experiment, and I don't have enough replication to do stats, but I thought the results were interesting enough. My main take-aways were:

1. As Claude stated previously above, it is important to have a completely stable cider before adding nutrients for bottle conditioning. It turns out that two of the batches weren't stable enough, and I should have let them sit a bit longer (Katja Wild, Ginny Wild). I primed them with 10 ppm DAP, and these batches produced excessive sparkle, in my opinion, and it was necessary to have a glass close at hand to catch the cider as it welled out of the bottles.
2. The wild-fermented batches that I primed with 20ppm 71B (Bear Creek Sour, Jonathan Gold Crab Wild) produced more sparkle than I wanted. The Jonathan Gold Crab Wild batch was downright explosive when I cracked the crown cap open. I suspect that 71B is a high N-use efficiency yeast, so although the wild yeast had stalled out in what appeared to be a stable cider, this cider was not stable with 71B, leading to more effervescence than expected. Take-home: It may be better to prime wild-fermented, stable ciders that have residual sugar with DAP, rather than with commercial yeast.
3. Priming a cider originally fermented with D47, and that was stable with residual sugar for over a month or more at ≥ 14 ˚C, I found an average SG drop of 0.0056 when I added D47 @ 20ppm. These data are not really comparable to my DAP results, unfortunately, because the two batches I primed with DAP weren't actually stable when I bottled them (oops).
4. Data not shown: 
   1. Lalvin 71B does not measurably affect total acidity. I used a 0.2N NaOH titration kit and a 15 mL sample to test acidity. There were no differences pre/post bottle conditioning for malic acid concentration.
   2. Lalvin 71B does not dissolve well (at least in my hands, and using warm tap-water in Boulder, CO); this meant getting a nicely even, distributed suspension in the bottling bucket was difficult, and I think has lead to varying levels of carbonation from bottle to bottle.

Happy Fermenting!

Courtney

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Courtney Meier | Plant Ecologist | Cider Hobbyist | Boulder, CO

[Claude Jolicoeur]

Nice experimentation!

Le samedi 20 février 2021 à 20:43:44 UTC-5, Courtney Meier a écrit :

1. As Claude stated previously above, it is important to have a completely stable cider before adding nutrients for bottle conditioning. It turns out that two of the batches weren't stable enough, and I should have let them sit a bit longer (Katja Wild, Ginny Wild). I primed them with 10 ppm DAP, and these batches produced excessive sparkle, in my opinion, and it was necessary to have a glass close at hand to catch the cider as it welled out of the bottles.

You will probably find that these will settle with time. If you wait another year or so, the cider will still be sparkling, but will not gush out as much...

1. The wild-fermented batches that I primed with 20ppm 71B (Bear Creek Sour, Jonathan Gold Crab Wild) produced more sparkle than I wanted. The Jonathan Gold Crab Wild batch was downright explosive when I cracked the crown cap open. I suspect that 71B is a high N-use efficiency yeast, so although the wild yeast had stalled out in what appeared to be a stable cider, this cider was not stable with 71B, leading to more effervescence than expected. Take-home: It may be better to prime wild-fermented, stable ciders that have residual sugar with DAP, rather than with commercial yeast.

This is an interesting finding. It would mean the wild yeast could stop working while there still is some nutrient there, that a yeast such as 71B could use.

1. Priming a cider originally fermented with D47, and that was stable with residual sugar for over a month or more at ≥ 14 ˚C, I found an average SG drop of 0.0056 when I added D47 @ 20ppm.

This is quite similar to the results I get.

One thing, you went to rather high dosages, and this is a bit risky as you found out. For my part, I prefer a cider that is less sparkling than too much! Hence I tend to be more conservative with my dosages...

Another point of consideration, is that keeved ciders tend to need a higher dosage in order to get the same sparkle. Probably because these generally are better clarified at moment of bottling than an unkeeved cider.

Claude