Disgorging questions

[Jason MacArthur]

Well, we are again in the painful midst of learning the art of disgorgement.  This year we got some liquid Nitrogen, so were using this instead of the salt/ice bath, as I have been told that this is a way to get more consistent results.  What I was finding was that if I left the bottle in the N for long enough to get good ice formation in the neck,  when I opened the bottle some of the yeast/bentonite plug actually appeared to freeze to the bottle, rendering the process useless.

   I don't know if the N is actually too cold to be effective, or if there is some other way around this.

  Any advice appreciated!

Jason 

[pkb]

You make no mention of scale, but I have settled into using dry ice and isopropyl alcohol, since it easy to access. I am a home cider maker, so need to disgorge only a few cases at a time which makes the set up not too cumbersome. The solution gets down to about -20C, and I freeze to about 5-7 mm deep on the neck in about 5 min. Pops out perfect almost everytime, and the resulting cider and perry is clear as a bell. Zero yeast sediment. How many g/l of sugar are you priming?

[Cider Supply, LLC]

Never used L. nitrogen, just have had good luck on small scale just putting bottles in freezer until neck freezes first then disgourging. Have heard that L. nitrogen can weaken bottle necks if rest of bottle and contents are not already close to freezing first.

[nfcider]

I would like to experiment using dry ice,but finding it difficult to source,several people have said it's due to Health and Safety issues from not being used at events etc.
Barry Topp
New Forest Cider

[Jason MacArthur]

Our scale is micro-commercial, so for this test disgorgement we were hoping to finish 15 cases.  Even at this scale the timing of the freezing becomes a headache, hence our hope to use a colder material.

The bottles were all right around 0 C, having been left out overnight in our abnormally warm weather.  We prime at 20 g/L sugar, and this cider was bottled in April, so has been sitting on the lees now for 8 months or so.

I almost want to try freezing the neck then actually warming just the tip of the bottle, so the cider behind would be frozen but not the sediment plug.  But maybe I shouldn't try to further complicate anything!

[pkb]

I imagine it is always a challenge to scale up from hobbyist level to small scale commercial. I have a template cut out for 12 bottles that hold them up side down in the tub of dry ice/alcohol, and can manage a cycle time of the 5 min as I work thru them.  How deep is the lees in the cap?  I have primed up to about 15 g/l, and even then found the lees from a well riddled bottle is only 1-2mm deep.  Really just a film in the bottle caps of  500ml, 22 oz, and 700ml bottles.  This really surprised me.  The shallow lees have always tempted me to minimize the freezing to cut time but also to help the plug to escape with ease.  

I do tell the  wife that in order to get this disgorgement thing dialed in, we will require a research trip to the Champagne region of France and get some tips from the masters.

[Jason MacArthur]

Our lees piles are significantly deeper, more in the range of 8 or 9 millimeters.  This is the first year I have used a riddling aid, some proprietary bentonite formulation, and I also use nutrients at bottling to reduce the possibility of H2S.  Could it be that this is simply too deep a lees plug to come out cleanly?  I have tried exposing the neck to the N for varying amounts of time, and if I submerse it long enough to get decent freezing in the neck I have terrible problems with it sticking to the glass.  If I disgorge before that long I lose more cider and am less confident that lees are not being washed back into the cider as I bring the bottle upright, but do not have the sticking issues.    Very frustrating!

Jason

[Anders Kjær]

Hi Jason
You say that this year you have used riddling aid. Have you noticed any difference in regards to compacting the lees?
I have some bottles turn up side down for test purposes and can see that most lees settle down nicely, but there is still a fine dust like deposit that clings to the bottle sides where the neck starts?

I am curious whether riddling aid will help with this problem?
Cheers Anders

[pkb]

Anders. Give the bottle a good spin to lift the sediment from the bottle side. The vortex also will cause it to collect towards the center and fall mostly into the cap. This is where bottle shape comes into play - smoother transitions help. Sharp shoulders are collecting points . Doing this at most 2 times, give a week or two between actions, is pretty effective.

[Francis Bonenfant]

I'd say liquid nitrogen is overkill and way too cold for what you are trying to do. With such a low temperature you may even make the glass brittle. There's a reason the commercial guys use coolant baths at -20C or so and not -196C. That said, perhaps you simply don't wait long enough for your sediment to compact on the cap or bottle when the cider is not clear enough. 9mm of sediment seems like a lot. 

[Richie McBride]

I've been making our champagne cider for three years now.
Started with brine in an ice cream maker.
Needed a lower temperature and bigger volume.
I now use a 25% solution of calcium chloride in a bath in a freezer. It stays liquid at -30°C. I have a plywood plate over this with 15 holes at just the right diameter to get about 45-50mm of the bottle neck immersed. 5 minutes in the bath gets a perfect frozen plug. This disgorges perfectly. We haven't used finings, the bottles are usually upside down and riddled for four weeks, and the sediment layer is fairly deep , 3-5mm.
It works brilliantly. We did over a hundred bottles this year, next year it will be about 500. The calcium chloride is readily available as refills for passive moisture traps. I pay about £1 per kg. We always rinse the bottle necks before removing caps, this may assist with easy discouragement.
I'll try to post a photo of the frozen plug

[Jason MacArthur]

Well, using the liquid N was an interesting experiment, but I tend to think it too cold for the task.   I have had better luck in the past with ice and salt, I was just hoping to avoid the downtimes that always seem to arise as I wait for one batch of bottles to freeze, or find some not quite frozen, etc.  I do think I will seek to develop some other system, particularly as the issue of making the glass brittle concerns me.  I don't know much about glass at all, but did have a few bottles break in my hands.  This could have been due to freezing liquid in the bottle generating pressure as it turned to a solid, or it could have been related to a weakening of the glass.

Doing this though made me realize I am still a little fuzzy on what exactly is supposed to be happening during the freezing process.  I know that one wants the lees plug to be frozen, but is it also desirable to have frozen cider behind the plug acting as a dam while the bottle is open?  Or is the objective of freezing merely to freeze the lees plug into an unified whole?

[Claude Jolicoeur]

I don't do riddling and disgorging myself, but I know of some people who do it successfully without freezing. The guy who was telling me about his does about 20000 bottles a year manually this way... Just taking the cold bottle upside down, opening while rotating it, and the lees are expelled. Maybe there is a bit more loss that way, but I understand that as one gets the twist, it goes quite well (I guess that when you do 20000 bottles you get the twist at one point...). Maybe worth a try?
Claude

[Francis Bonenfant]

Yes Claude, this is the old way of doing it.
https://www.youtube.com/watch?v=TV0_KM3j3z4
It's called disgorging ''à la volée'' which means that you tilt the bottle upward and pry off the cap before the gas bubble reaches the sediment and disturbs it. It takes a lot of skill but it works.
Disgorging ''à la glace'' means freezing a plug before disgorging, which makes the operation easier.
There are also ''bidules'' which are plastic cups that you put in the neck of the bottle before riddling: https://www.youtube.com/watch?v=70LJxBOkNLs
The sediment accumulates in them and they help with disgorging as one solid plug, even easier if you also freeze them. They act a bit like the cup in shotgun shell.

[pkb]

As a home cider maker, I do use the 'a la volee" method most of the time. ( I thought it was just cheaty disgorging!) I find that when done well, it gets almost all of the job done, and when the bottle is left to rest for a day or more, the entire bottle still pours clear. The freezing method is a saved for special occasions, gifts and when a perry/cider mix is in the bottle, which tends to produce a slight pectic gel and deeper lees.  If I have not gotten to disgorging in volume, it is easy enough to do on a bottle and take immediately to table.  Getting competent at this reduces greatly the barrier to producing very fine in bottle conditioned cider, and it makes really no sense to do it any other way.  Just a final step in the cider making process.  

[Francis Bonenfant]

I'm curious about one thing: after disgorging à la volée, do you dose with dry cider or sweet liqueur? If you dose with sweet solution, do you have any issues with bottle bombs/refermenting in the bottle again? Also, how long do you cellar the bottles and at what kind of temperatures before disgorging?
If this works, it seems like a great way to make sparking sweet cider! But without freezing the necks, it seems a bit risky that yeast would still be left in the bottle.

[pkb]

I never backsweeten any of the cider I consume at home. Probably an entirely different and controversial discussion, but after tastings with over 50 people ( blind tests vs commercial ciders) no one has ever wished it were sweet. Just a matter of personal taste, but I think backsweetened cider is overrated. I usually let it condition for minimum of 3-4 months before testing, and work thru the cases over a year or so. Some have been upside down now for two years and only seem to get better. The longer in bottle, the better the mousse as well. Temps are usually just cellar temps.... 55F more or less.

[pkb]

Oh, and one more trick. When filling bottles, I overfill to compensate for the potential loss while disgorging. Usually comes out about right... Again, not commercial, so precision fills are not that critical.

[Anders Kjær]

Thank you for sharing all your tips. Very much appreciated.
Cheers Anders

[Scrumpy-]

Hello Old Spot,

Your comment about the mousse improving with time caught my eye.  I have a cider that has been conditioned in the bottle for 80 days at 65-70 deg.  The pressure stabilized after 40 days around 3 volumes CO2.  When I opened the first bottle, it gushed but didn't geyser.  When poured, the carbonation is between that of beer and  champagne which suits me just fine.  I planned to age this batch for at least another 3 months before drinking it.  I considered disgorging it as a solution to the gushing problem but wonder if time in the bottle will fix the problem.  Can you comment? 

[Old Spot]

Scrumpy - the true answer to that is probably left to science, mine is just a general observation, but really not ALWAYS the case.  A scientifically inclined cider making friend suggested that mousse formation might be a function of yeast cell breakdown (a function of time), the exact mechanism I am not familiar with.  Be really interesting to know more about it.  I had some 3 year old on lees cider last night with no mousse.  High in acid American style cider in this case however, so maybe acidity counteracts mousse formation?  More research required.  Wild Pear blends tend to have the best mousse and are lower in acid.

"disgorging as a solution to the gushing problem".  Not sure what that means.  These are upside down, right?  I think the colder the better to reduce pressure (that scientific mechanism i do understand), but the 'gushing' might actually be a function of the exact angle at which the cap is removed.  As Claude referenced, getting that angle and timing just right has a lot to do with practice.  

When bottling multiple cases, I usually leave a few upright and start to test those after a time.  This gives a good reference to status of carbonation, but also is a control for the 'gushing' nature of the process as it eliminates the disgorging complications.  If the upright bottles are nicely bubbly and open without gushing, and the disgorged ones geyser, then the cause is the disgorging process.  Practice improves results, but I doubt perfection is in the cards.  Glad I don't try to make money at this, or I would be tempted to just artificially carbonate in tanks and that would be sad and boring.