The Girl Guide organisation has received complaints that this year's biscuits are dry, but says the recipe hasn't changed.
Girlguiding chief executive Ruth Teasdale says biscuit maker Griffins is testing its product.
However she says taste and texture are the same, and it's the appearance that hasn't met expecations.
The logo has not been put properly on some of the plain biscuits and they are affected by dimpling on the back, she says.
Ms Teasdale says Griffins is working hard to put it right for the organisation, and people not satisfied with the product are entitled to a refund.