By: Halacha Yomit team of OU KOSHER
Is it permitted to puree fruits or vegetables without checking them for insects?
The Terumot Hadeshen 171 writes that it is permissible to mill and grind infested wheat into flour provided one removes all obvious signs of infestation. Even though it is possible that there are more insects, so long as one does not know for sure, the wheat may be milled. However, produce which is known or generally assumed to be infested may not be milled. This opinion is quoted by Shach (YD 84:40). On this basis, it is permitted to wash vegetables or berries to the point that they are relatively clean and then puree them.
One further caveat is that this is only permitted if the pureeing is done primarily because that is what the recipe calls for, and not for the purpose of obliterating the infestation.