How to Boil Octopus so as to make it Tender, or Lessatura del Polpo per Ridurlo Tenero: Octopus is delightful, but it can be devilish to cook, going from soft and tender to rubbery and back as it sits in the pot; the trick is to either remove it before it goes rubbery or have the patience to wait until it passes through that phase. Here's a trick for boiling it that will yield tender octopus every time.