Dimple in cork persisting after corking

Question

I bottled my wine bottles with a Portuguese floor corker, but the dimple is still in the agglomerated cork after a year.

I was told to:

1. Wait three weeks with the bottle upright.
2. Store a year with the bottle upside down to keep the cork wet.

What measures can I take to minimize that dimple? Why doesn't it show up on commercial bottles?

I'm just hearing about potentially hacking in a broader surface with a shaft collar at the end of the aluminum rod that presses in the cork.

Answer 1

Using a coin reasonably smaller than the 18.5mm diameter to reduce the pressure and spread out the force over a larger area is another hack.

https://www.winemakingtalk.com/threads/dimple-on-top-of-cork.6484/

Answer 2

OK so the issue seems two-fold:

1. The dimple can be reduced with a plunger that has an increased surface area slightly. I see this on some models where it bulges out a bit on the bottom.
2. This is the big one: the quality and appropriateness of the corks you choose matters. So fresher corks (not dry, crusty, agglomerated ones) can compress more easily and spring back from the deformation. And it seems, at least for my case, that #8 corks fit much less tight than #9 corks. So get the good, fresh corks (e.g. twin-disc or full cork) ones from your local hobby shop, not Amazon.