The sample in Bernd's video,,, is "normal" Surströmming.
(I know this because the can is flat and it didn't spew into the air, when the guy opened it).
Hans only brings "Premium" Surströmming.
The cans he brings are pressurized by the fermenting fish.
(The tops of the metal cans' are stretched into an oval shape)
He opens them underwater so they don't spray Surströmming juice all over him and the crowd.
NOTE: During Al and Charlie's sample opening; there was enough pressure in the can, that it sprayed juice into the air. {"even though it was underwater"}
Update; Good news Mark, {you lucky Devil}.
I talked with Hans.
He said, {since your a rough/tough Devil Dog/Marine}, he's looking for a "
Extra Premium" Can of Surströmming for you to sample!!!

Survival Hint: Don't forget the Crackers and Schnapps!!! {Lots of Schnapps!}
Ride safe, Ted
PS: We're still waiting to find out if we're gonna support 2 "OtP" Traveler's this year.
(Personally, I think we REALLY need to send 2. {So Dan can enjoy the Surströmming too}). <evil grin>