Shatter mechantics, someone explain...

Hey,

So, I'm playing glacial cascade mines, like so many others do at the momemt. I'm using 2x the long winter so my mines now deal 100% cold damage. White monsters and blue packs die in one shot. According to the wiki, when monsters shatter on-death effects (most of them) are bypassed, "Spines shot by the Porcupine Goliath".

What I would like to know is when does shatter occure? It feels quite weird imo. Do I have to hit the monsters with GC to freeze them, then hit them again in order to shatter, or can they shatter streight away? If they can shatter streight away, what determines if they do? I know they do when I crit, but can they also shatter without crit? And if so, how and why? Porcupines are a big problem for me at the moment as they for some reason doesn't shatter, which in my opinion they should if you're killing them in 1 hit and it's 100% cold damage... can someone clarify the condition for shatter please...

You shatter enemies when you kill them while they're FROZEN. Freeze effect occur when you crit with your cold damage or at % chance to freeze with enough damage. You may read here https://pathofexile.gamepedia.com/Freeze to know how much damage is enough to freeze enemies.
If you don't want to shatter enemies, then firstly, you must prevent your skill not to freeze enemies, easiest way is use this gem https://pathofexile.gamepedia.com/Elemental_Focus_Support

If they die while frozen they will shatter.

If you crit, then it will freeze them. So they will shatter.

If you don't crit, then they will only shatter if you freeze them. Chance to freeze is a stat you can get from items, gems, passives etc...

They can freeze and die from the same hit, and will still shatter.