Only if the process was commonly known. Alchemists were quite a secretive bunch. For example, if you asked most people to name a famous alchemist they'd probably come up with nothing, despite Isaac Newton being one. https://en.m.wikipedia.org/wiki/Isaac_Newton%27s_occult_stud...
It doesn't matter - even if you're the only one to know the trick, once you start dumping large amounts of gold on the market, its price will start to go down. Gold isn't something that gets easily used up, so the more of it is in circulation, the cheaper it gets.
This is the same trick economists play when saying "inflation doesn't matter". It doesn't in the steady state, but in the meanwhile, I printed the money and gave it to my friends, who do you think is going to end up owning all the hard assets?
Intriguing.
Operational security was also terrible, so it wouldn't have been kept as a secret limited to one country for long.
If you want to profit from making gold, you have to spend gold, and that's going to get noticed very fast. Its not like the common man was spending gold coins on a regular basis.
But they'll surely tell it to their wife and kids at some point. And somebody should leak the recipe.
>Isaac Newton
Oh. :D