Toffee Crisp and Blue Riband bars can no longer be called chocolate after Nestlé reformulated their recipes due to the increasing cost of ingredients.

The Swiss conglomerate now describes the treats as being “encased in a smooth milk chocolate flavour coating”, rather than being covered in milk chocolate.

In the UK, a product needs to have at least 20% cocoa solids and 20% milk solids in order to be described as milk chocolate, a level each product fell below after a higher amount of cheaper vegetable fat was used.

Nestlé said the changes were necessary due to higher input costs but were “carefully developed and sensory tested”, adding there were no plans to alter the recipes of other chocolate products.

A spokesperson for Nestlé said it had seen “significant increases in the cost of cocoa over the past years, making it much more expensive to manufacture our products. We continue to be more efficient and absorb increasing costs where possible”.

Toffee Crisp was created in 1963 by John Henderson, the great-nephew of the man known as the toffee king John Mackintosh.

Blue Riband, which draws its name from the prestigious transatlantic liner award, was launched in 1936 by Gray Dunn & Co in Scotland, a subsidiary of Rowntree’s, later becoming part of Nestlé in 1988.

The cost of chocolate has increased sharply as cocoa prices have soared after poor harvests in the key growing regions of Ghana and Ivory Coast over the past three years, amid extreme temperatures and unusual rainfall patterns driven by the climate crisis.

In October, McVitie’s reduced the amount of cocoa in the recipes of Club and Penguin bars so much they are now only “chocolate flavour” after parent company Pladis chose to use cheaper alternatives to the main ingredient in chocolate.

Chocolate prices in Britain rose 18.4% compared with last year, analysts at the market research firm Worldpanel said on Tuesday.