Bookbinding

Good day.

I'm a newbie to making leather bindings with paste. The problem I'm having is a staining of the leather, apparently by the absorbed paste.
I'm using veg.-tanned, aniline-dyed Packer Leather bookbinding kangaroo, whisky (tan) color, .6 mm. I'm moistening the hair side with distilled water until the moisture starts to show through on the flesh side, then I paste the flesh side, wait for absorption, repaste, and apply the leather to the boards. I'm using Talas pre-cooked wheat paste and Lineco acid-free boards.

The work dries with dark patches. The overlap of the thinned edge fold-over is particularly dark.

I've tested the leather itself, and it will take a total wetting and drying cycle with no discoloration whatever. Add the paste and the stains appear on drying.

Any suggestions?

Many thanks.

Fellow newbie here aswell. Iv been looking abit into the "how to´s" for binding and i see that it hasnt been updated for a while. Any kind soul willing to help out? I also have a few questions regarding binding with paste but since noone has anwserd here im guessing that perhaps noone is around with this knowlidge? // Regards Stefan