McVities has insisted it has not changed the recipe of the biscuit part of its chocolate digestives after a blind test panel concluded the new version with more chocolate tasted worse.
The biscuit brand officially launched its reformulated biscuits last week and claimed it had increased the chocolate content by 3% to provide a more even coating.
But a Which? blind taste test, performed by a 30-strong panel, found that two thirds preferred the old biscuit, with many preferring its crunchier texture.
A spokesman for United Biscuits, which owns McVities said: The key point to make here is that we have not changed the recipe of the biscuit part of this product in any way, we have simply increased the amount of chocolate to provide a more even coating on the biscuit. We have increased the amount of chocolate by 3% but this equates to a 1% increase when then whole biscuit is taken into account.