C'mon let's twist again...
We finally have our guts ready, well cleaned, softened, hardened, selected: we are ready to use the wheel and give some twisting!
...then we take our protostrings and we put them on the frame, where we give more twisting, we check the tension is fine, we constantly check they don’t dry too fast.
Uhm.... this IS tricky... the sulfuration...
For sure they did it till the 80s, in Italy... and when you ask why to a string maker the answer is always “to have the strings white and beautiful”
To sulfur the strings you have to bring all the frames in a special room, or sometimes a sort of pit, light some sulfur, and close it for a night. On the next day, give air and take the frames out.
I doubt all this was done only to obtain a whiter colour, what was the matter with yellow strings especially if you didn’t know you could have white? I also doubt it was to disinfect them, we are speaking about music, not surgery.
But the experiments I have seen did no result in consistent quality, results were always different, strings could be gummier, stiffer, weaker...
Furthermore, today it is avoided by the low to spread sulfur gas in the air (if you are a company, if you are a farmer you can, because you have to disinfect your cellars), and anyway it is not that healthy...
Looking forward to your comments below, chemists are very welcome!