Failed Back Sweeten, Sorbate Question

I'm making a simple 5 gallon batch of cider from aj concentrate with Wyeast cider smack pack. OG was 1.055 and after 3 weeks in primary and no airlock activity for 3 days the FG was .998. My plan was to back sweeten with honey. I assumed the fermentation was complete, so I racked to secondary onto 5 campden tablets and 2.5 tsp of K-Sorbate. Let sit for 1 week and added less than 1lb of honey to bring SG up to 1.005. Thought all was well, but after 48 hours fermentation has restarted, although slow. Its fermenting about a point every 2-3 days, guess I still had some active yeast. I want to give back sweetening another shot after it finishes this time. I will cold crash this time to make sure all yeast is out of suspension (should have done it in the first place, no fridge space).

I'm sure by then the sulfites will have dissipated, so I'll have to dose it with campden again. My main question is... Will the sorbate i originally added be enough to inhibit yet another refermentation? Or will the cold crash and racking take it out with the yeast. Should I add more K-Sorbate?

Thanks for the help.

I also have the same problem, I have a 5 gallon batch of Applewein, and I allowed mine to ferment to .994, Degassed, then added 5 camden tabs and 1 tablespoon (3Tsp) of KMet to keep the fermentation from restarting and waited 6 days and backsweeten up to 1.004 using 2 cans of frozen apple juice, and waited overnight to see if it would start to referment, and it has restarted, just like yours. What can I do at this point? add more camden and Kmet, or just wait until it goes dry again and try to backsweeten again?

Potassium sorbate will not stop fermentation just slow it down. It stopped the little yeastees from repopulating. I back sweeten with 4 cans of concentrate and 2.5 teaspoons of potassium sorbate with no issues but I keg it.

i've had it happen too. i don't think the sorbate dissipates with time so i wouldn't add more. my bet is that if you cold crash and rack again carefully it won't restart... but i've never used that yeast. are you kegging or bottling? i keg all my backsweetened ciders now and don't bother with sorbate or sulfite, just keep them cool and they're ok, at least with ale yeasts that can't cope with fridge temps

Thanks dinnerstick, thats what i was thinking.

I will be kegging it for a wedding reception and was going to bottle any leftovers for the guests to take and didn't want to risk bottle bombs. I cold crashed it for 7 days and seems good now, so far.

Hopefully there wont be any leftovers and problem solved. I think I'll be avoiding preservatives from now on and just keep it kegged.

i now bottle and pasteurize any keg leftovers. no risk of 'hot bombs' (ahem) since you already know their carb level. far less nervy than heating bottle conditioned cider

I think waiting a week after treating to add sugar is too long. I add the treatment in my sugar solution with no problems so far. I then wait a couple weeks to bottle just to be sure.