The answer is Pip replaced it with tar water. Since Pip is excessively bustling stress over what the Tickler will do to him to eat much. Mr. Pumblechook attempts the brandy, just to dispatch into a hacking fit. Pip unintentionally filled the brandy bottle with tar water to influence it to appear like nothing had been stolen. Everybody is completely befuddled with reference to how tar water could have discovered its way into the container.