OK- I have never made wine from kale, but talk of juice is not the first approach I would think that kale calls for. I make wines from flowers and leaves and even roots (elderflowers, chamomile, nettles and marshmallow (the plant) you don't juice those. You extract their flavor either by making a tea (so heat and water) or you use alcohol to extract the flavor. The first approach might be to take a couple of gallons of kale and a gallon of water, add say, 2.25 lbs of sugar and boil this for ten minutes to make a tea. (if you are using honey - a kale mead - I would add the honey AFTER the tea has cooled). Not sure how flavorful this tea will be so you need to decide whether to strain the tea right away or allow the kale to stay in the must for two or three days or for a week.. I would pitch your yeast. Perhaps a Belle Saison yeast. You might want to add lemon zest and tannin. And then ferment dry and taste - It may want back sweetening. This may also need some lemon juice to give it a kick
The alternative is to make a traditional mead (honey, water, nutrient and yeast) . This could be 12% ABV or it could be a session mead (say 6%) and when you are ready to rack to the secondary you add the kale and use the alcohol to extract the flavors. Now you have much more control over the process as you can taste this every day or so and determine whether the kale needs to sit in the alcohol for a week or a month. or... ? Again, this will need tannin and acidity.
Of course, this may taste like crap... BUT I have made zucchini wine and that was delicious and I have made a turnip wine and that too was wonderful.
There is a third approach you might consider and that is to cover a quantity of kale with some cheap vodka and agitate this a couple of times a day for say, two to three weeks and then taste the vodka. If the kale vodka excites your palate you know that kale wine has potential. If the vodka is awful then the wine may not be the direction in which you want to take this kale.