Wow, this went nuclear quick.
@RPh_guy you may know your stuff, but you do come across as a bit pedantic. This is just feedback not an attack. Just curious have you personally done any of this testing? Or is this a theoretical discussion? I'm ok with either. I do have a background (shockingly distant now) in analytical chemistry, so I hear where you're coming from.
Me personally, I do think that in the end, I will be doing YAN testing, but, in 4 years I've gotten away without. I am a huge believer in adequate yeast nutrition. So, I do think it's important. It's just that standard supplementation works so well and basically every time, that YAN testing goes into the background. My guess, is, that kit's are already fed with YAN, so no YAN testing needed for kit any wine making. For grape wine making, though, it's in play. Especially with central valley grapes (what the East Coast guys get) grown for yield.
Let's start over on this topic, because it is a good one.
@Ajmassa is a good dude and you should lighten up a bit. Just sayin'.
And BTW there is a lot of info in the "stickies" that is wrong/outdated/silly in retrospect.
So don't go away, just mellow out a bit. Chemistry is good and mostly makes life better. If you have special knowledge here, welcome to Wine Making Talk!