In this case I have a customer interested in sparkling cider, but the question would apply to wine / cider / mead etc.
Basically how would you backsweeten if you intended to bottle condition the wine with yeast like champagne?
My best answer right now would be to use conditioner with sorbate etc / keg and force carnonnate. But if you wanted specifically to use the suspended yeast, is there a process or recomended unfermentable sugar that would be appropriate?
Yeast would be Lalvin 118.
I assume lactose would not be appropriate for cider or wine.