Pot. Sorbate/sulfite ineffective or wild yeast?

[BeerKillLogic]

Good day to all!

So here's the deal. I'm on my 3rd batch of cider. Prior to this one I have only done dry ciders and bottle conditioned.

This time I wanted to aim for a semi-sweet to sweet cider. My procedure is as follows.

4 1/2 gallons store bought cider
brown sugar
yeast nutes
safale-05.

OG 1.054
FG .998

I left this in primary for 5 weeks. I then added Potassium sorbate and metabisulfite as directed on the package and allowed them to do their thang for approx 48 hours.

I took a second empty carboy, poured in1/2 gallon of the original unfermented cider to sweeten, and racked my fermented treated cider on top of this.

FG after back sweetening now was 1.010

I stuck it in the closet and allowed to clear/condition for 2-3 weeks. During this time there was ZERO activitiy as far as the airlock is concerned, and it cleared brilliantly.

I wanted to take a sample for tasting as well as confirm my FG. This time my FG showed 1.007! Some how it had dropped a few points. I planned to take another reading in a couple days to see if it changed even more.

I took the 1.007 reading on a friday. By saturday night I noticed white foam, almost a thin krausen like foam forming around the surface. Prior to this was perfectly still.

By sunday it was a much thicker foam with big bubbles, rather than tight little ones to form the krausen like beer. Also at this time the airlock was rocking away again and the cider is no longer clear

How could this be? Did some how the original pitched yeast become active again, or does it sound more like an introduction of some sort of wild yeast or bacteria?

Either way, I thought the pot. sorbate/meta would keep ANYTHING from fermenting the left over sugars?


Can I treat the cider once again or will this be too much. Such as, re-backsweeten and treat with sorbate/meta?

I seriously tried to keep this short. Thanks in advance for your help!

 

[Yooper]

Remember that sorbate doesn't kill yeast- it inhibits yeast reproduction. That means that there needs to be very little yeast in the cider, so that fermentation can't restart.

If you just dumped in the sorbate into a cider that had lots of lees (sediment), and billions and billions of yeast in suspension, fermentation would restart when fermentable sugars were added.

Next time, if you want to stabilize with sorbate, make sure the cider is completely clear (like you can read a newspaper through it), and without any sediment at all in the bottom of the vessel after at least 60 days in that new vessel.

 

[BeerKillLogic]

Ok, makes sense.

I checked the gravity last night and it fermented all the way down again to .999. Shall I just leave it for another two months, add sulphates and what not, and then back sweeten?

My concern is adding too much Potassium sorbate/meta and what adverse affect it will have.

 

[lolznrofls]

Might I suggest you read the thread on stovetop pasteurization. .I think its an awsome alternative..my wife is sulfite sensitive so I cant use them..😆 but I can get over it..stovetop pasteurization is simple and kills the yeast so no worry about over carbing..no one like bottle bombs!.. but I wouldn't know anything about that...what 'll atleast till my wife opened that bottle last weekend..lmao.. cheers to all!

 

[BeerKillLogic]

I've read that thread. From my understanding stove top pasteurization comes with its own issues I'd rather avoid. Anyway, I'll be kegging the batch and then bottling from keg so I'd just rather have it be ready to go once in bottles.

 

[Newsman]

Cold-crash your cider and then rack it off the lees before adding the sorbate / K-Meta.

 

[BeerKillLogic]

Ok, so right now it's technically in secondary but because of the refermentation I should transfer to secondary treat w sorbate /meta and then allow this to sit for a very long time before backsweetening?

 

[Newsman]

Ok, so right now it's technically in secondary but because of the refermentation I should transfer to secondary treat w sorbate /meta and then allow this to sit for a very long time before backsweetening?

Not necessarily. What I would do is cold-crash it (say 35 degrees F for 24-48 hours) and then transfer it to another carboy and treat with sorbate / meta. Then you can try to backsweeten if nothing happens for 24-48 hours after that.