I have never successfully "smacked" the envelope open in a smack pack. I've tried repeatedly. Watched videos, etc.
That said I have always had very fresh yeast that took off like a rocket, so it hasn't really been an issue. Just annoying that I haven't figured this out.
I've found it works best to trap the packet in a corner of the package. Then keep it there with one hand and use the heal of my other hand to compress the packet and pop it. Some are more difficult than others but trapping it always gets the job done.
Paul
I find if the packet has started to swell at all it can be very difficult to trap and pop the internal pouch.
In which case, why bother? If the packet is swollen, you already know the viability.
How’s that? If the pack arrives slightly swollen and I stick it in the fridge and don’t use it for a month, how do I know what condition the yeast is in? I have taken packs out of the fridge that are still slightly swollen. I doubt that is a sign of active yeast.