FAQ for Nespresso ® Brewers
Nothing is wrong. The cap is small by design.
The cap is not meant to be a tight fit or close to a tight fit. It is designed to be used with a filter which comes in each package as a sample and we also sell the filters by themselves.
We originally did make the cap a tight fit, but what we found was that it put too much pressure on the outside walls of the vertuoline capsules causing them to get stuck in the machine. We got a lot of complaints about that. We found that by making them loose it did not push out on the capsule.