The dish that turned out differently may still deserve to be tasted without apology.

Announcing a failure before anyone has tried something changes how it is received. The apology arrives first, everybody eats while reassuring the cook, and a perfectly decent meal is experienced as a disappointment because it was introduced as one. Different is not the same as bad, but an apology offered in advance decides the question for the room. Your framing is usually more powerful than the food.

When something does not turn out as planned, put it on the table and say nothing. Let people form their own view before you offer yours.