Back Sweetening Cider Keg

[simplecj]

So, I'm new to kegging, but loving it a lot after 7 years of bottling. Just kicked my second keg of hard cider last night. I have a 3gal carboy of cider that I want to mix with a couple gallons of grape juice to make a lower alcohol wine cooler for my wife. Cider is 7.6%, mix 3:2 should put it around 4% which is fine for my wife who doesn't drink that much. I'm actually looking forward to trying it out. I've done some appleberry wine from concentrates that turned out delicious. This will be my first time doing a heavily back sweetened wine and I don't want to screw it up.

My question is, do I need to kill off the yeast if this will be kept around 32F in my kegerator? I tried lightly back sweetening a 1 year old perry I did last year and it ended up carbonating in the bottle even though I used sulfites before bottling and after I had let it bulk age for over a year in my cold room at ~50F. I don't know how back sweetening works with kegging in a kegerator at low temps. I know that it would spell disaster if it fermented in an already force carbed system. What's the best way to kill off yeast? Apparently I can't trust potassium metabisulfites...

Just for fun, here's a pic of my Kegco KB309-2 kegerator with blacklight backlight... =)

 

[Yooper]

So, I'm new to kegging, but loving it a lot after 7 years of bottling. Just kicked my second keg of hard cider last night. I have a 3gal carboy of cider that I want to mix with a couple gallons of grape juice to make a lower alcohol wine cooler for my wife. Cider is 7.6%, mix 3:2 should put it around 4% which is fine for my wife who doesn't drink that much. I'm actually looking forward to trying it out. I've done some appleberry wine from concentrates that turned out delicious. This will be my first time doing a heavily back sweetened wine and I don't want to screw it up.

My question is, do I need to kill off the yeast if this will be kept around 32F in my kegerator? I tried lightly back sweetening a 1 year old perry I did last year and it ended up carbonating in the bottle even though I used sulfites before bottling and after I had let it bulk age for over a year in my cold room at ~50F. I don't know how back sweetening works with kegging in a kegerator at low temps. I know that it would spell disaster if it fermented in an already force carbed system. What's the best way to kill off yeast? Apparently I can't trust potassium metabisulfites...

No, if you keep it at 32F--ish it shouldn't start fermenting again.

Sulfites don't kill yeast- they are an antioxidant and are used for that purpose in winemaking. At 50 degrees, wine yeast can be active.

If you want to stabilize the cider, you can wait until it's totally clear, and no longer dropping any lees at all, then rack it onto sorbate (1/2 teaspoon per gallon) and campden (sulfite, 1 crushed tab per gallon), dissolved in a little water. The sorbate doesn't kill yeast, either, but it inhibits yeast reproduction so that is why it works in a completely clear wine or cider- the yeast would have to reproduce to ferment. It works better in the presence of sulfite, so that is why it is added with it.

Once that is done, you can let it sit a day or two and then add the juice/sugar/honey/whatever and it should not ferment even at room temperature.

 

[simplecj]

Potassium metabisulfite does kill "wild" yeasts and bacteria and is also an antioxidant. I actually used it to treat the freshly pressed cider for 24 hours before pitching my own cider yeast. I guess from reading a little more on it now, it appears most beer and wine or cider yeasts are more resistant to it than wild yeasts. However I swear when I bought it that is said to treat must with it before bottling for a still wine.... I'm confused I guess. Maybe I should look into some sorbate as you suggest.

The cider is super clear now, so it's ready to go. I'm just nervous that if I don't kill or inhibit the yeast I will regret it. Actual temp in the kegerator should be 32-38F, definitely staying under 50, shouldn't go above 40, but I haven't really tested my temps yet. It has a built in digital thermostat, so I'm not just guessing with a blind dial adjustment.

 

[Yooper]

Potassium metabisulfite does kill "wild" yeasts and bacteria and is also an antioxidant. I actually used it to treat the freshly pressed cider for 24 hours before pitching my own cider yeast. I guess from reading a little more on it now, it appears most beer and wine or cider yeasts are more resistant to it than wild yeasts. However I swear when I bought it that is said to treat must with it before bottling for a still wine.... I'm confused I guess. Maybe I should look into some sorbate as you suggest.

The cider is super clear now, so it's ready to go. I'm just nervous that if I don't kill or inhibit the yeast I will regret it. Actual temp in the kegerator should be 32-38F, definitely staying under 50, shouldn't go above 40, but I haven't really tested my temps yet. It has a built in digital thermostat, so I'm not just guessing with a blind dial adjustment.

Well, k-meta doesn't even kill wild yeast that well, not in the concentrations used in the must. It does a good job with other microbes, though. And ale and wine yeast strains are amazingly tolerant of sulfites. To use enough to kill the yeast would render the cider undrinkable. So the instructions to use it before bottling, without sorbate, are faulty for sure. It's primarily used as an antioxidant, usually at 50 ppm or more, by winemakers. At 50-80 ppm, the yeast wouldn't even be stunned let alone killed or stopped.

You can use the sorbate if you want. I don't care for it, as it has a flavor I can pick out a mile away, but many others make sweetened ciders and wine and don't even noticed the flavor so maybe you'd want to try a sample first, and add a tiny bit to see if you mind it.

 

[simplecj]

Ok, that is making sense now. I've been searching info on it and you're right, usually you would add sulfite and sorbate together for a still wine and only after the wine has completely cleared. Funny thing is, I think I actually have a bottle of Potassium Sorbate I bought years ago and never used... and apparently I forgot why I even bought it in the first place. LOL

I also found a thread about back sweeting cider in a keg and they agreed that if it's kept under 40F the yeast should not be active. I would prefer to avoid any additives I don't need. I'm sort of excited about the new options I have with my kegging system. Seems it's perfect for anything you want to back sweeten and carbonate, something that's pretty difficult or impossible to do with normal home bottling methods.