You'll know if you have bad gas more by how the car is driving. If there's a knocking, misfiring, metallic rattle from the engine compartment, then bad gas might be your issue. This will definitely show up more under acceleration and with a rough idle most times. The pic you attached looks normal.
You may feel like you have bad gas if you're running a tune for a specific octane and accidentally put a different octane in your tank.