The saga continues.
I cooked 60g butter (1/2 stick), a pinch of salt, 50g white wine, and 150g water in a water bath at 175F/80C for a couple of hours. The liquor that resulted smelled strongly of butter, but it had both a butter taste and a sour, off taste, which I think must have come from the wine. I chilled and strained it, then dissolved calcium lactate in it (2.5g per 100g of liquid). Here's where it gets strange.
To do reverse spherification, you want a liquid that has about the consistency of cream, so you add something like pre-set agar gel or xanthan gum. The latter is preferable, because it's very easy to scale the total quantities against the trivial addition of .5g gum per 100g original liquid.
I put the liquor, gum, and calcium lactate in the tube-bowl thing that came with my immersion blender and whizzed it. It turned white, like chalk, and foamed. It looked like thick cream. It had been transparent, now it was white. Strange....
Then I tried the same thing but replacing the xanthan gum with 10g of 1% agar gel, pre-set, and whizzed it together. It turned very foggy-translucent. Hmm...
Then I tasted both... And they were horrible. Bitter, acrid, and chemical-tasting. Awful.
After much thought, I decided to isolate the problem.
1. Water, calcium lactate, xanthan gum
2. Water, calcium lactate
Both came out clear and tasting of basically nothing at all. They have a very faint bitter hint, but it's extremely subtle. (The butter liquor thing, after these additions, was emphatically not subtle.)
So I conclude:
1. Neither calcium lactate nor xanthan gum were the problem, though one must be quite careful about the calcium lactate, as it clearly has a slightly acrid taste.
2. The right way to dissolve these ingredients into the water is NOT with an immersion blender, contrary to popular wisdom, as this seems to be picking up the traces of fat left in the butter liquor and producing an emulsion.
After some research, I learned that calcium lactate is fat-soluble. As a result, in theory (and I stress "in theory"), I should be able to dissolve it directly in flavored butter and spherify. Last time I had the problem that the butter froze in the cold water bath, which is a problem.
To test, I tried to dissolve calcium lactate in canola oil. Result: it's fat-soluble, but it sure as heck doesn't want to dissolve. I heated it a bit, and that helped, but if you get to the boiling point of water or so the stuff starts to get hard and scorched. We'll see on that one.
I now have the oil-lactate solution in the freezer in a little square mold-like thing. The idea is, when it is frozen hard, I will simply drop the block into the sodium alginate gelling solution. If I'm right, it will take a while to set, but after maybe 10 minutes I'll have a clear gel coating all the way around the oil ball. Then I rinse the ball well to remove excess solution and drop it into hot (140F/60C) water. If all goes well, the oil should melt and become clear and wobbly -- but the gel should remain intact.
Cross your fingers. This is getting irritating and exciting at once!