[Vocabulary] Food Plural or singular?

[lizynger]

Please fellows help me, how is correct to say:
Preserves food at its fines?
or
Preserves food at their finest?
The topic is about ceramic kitchenware.

Thank you in advance and looking forward to your reply!
Best Regards,
Lidia

 

[White Hat]

"at its finest", no doubt about it

 

[5jj]

"At its finest" is grammatically correct, but it sounds a little unnatural to me. I would say "at its best" or "at its freshest".