Many chocolate lovers consider shrinkflation a serious crime – and they have been vindicated after a German court ruled that the makers of Milka cheated consumers by cutting the bar’s size, while keeping the wrapper the same.

The three-week case in a regional court was brought by Hamburg’s consumer protection office. It accused the chocolate brand’s US owner Mondelēz of deceiving shoppers by cutting the weight of Milka’s classic Alpine Milk bar from 100g to 90g without significantly altering the distinctive purple packaging.

Shrinkflation, where product sizes are reduced but prices stay the same (or even go up), has become all too common as manufacturers try to offset rising business and ingredient costs.

After last year’s changes, the Milka bar was a millimetre thinner and the price increased from €1.49 (£1.29) to €1.99 (£1.72).

Ahead of Christmas, the Guardian revealed widespread shrinkflation in the confectionery aisle. This included lighter boxes of Quality Street and Celebrations, as well as smaller Terry’s Chocolate Oranges. Toblerone – another Mondelēz brand – had also suffered erosion with 20g shaved off its chocolatey peaks, reducing a 360g bar to 340g.

Chocolate has become more expensive because of poor harvests in west Africa, in particular Ghana and Côte d’Ivoire, where more than half of the world’s cocoa beans are harvested. When asked about pack size reductions in the past, Mondelēz has pointed to higher costs, ranging from ingredients such as cocoa and dairy, to energy and transport.

Mondelēz told the Bremen court it had informed German consumers about the change on its website and social media channels. However, a poll saw Germans vote the Milka Alpenmilch bar “rip-off packaging of the year 2025”.

It is not the first time Mondelēz has been in the dock over its shrinking chocolate bars. In 2016, it faced a backlash after it widened the gaps between Toblerone’s distinctive triangular chunks instead of putting the price up. Two years later, it reverted to the original shape.

The court ruled that a clear notice should have been included on the packaging to avoid confusion. The notice would be required ​for at least four months to allow consumers to take in ‌the ⁠change, it said.

The ruling is not final, with Mondelēz having one month to lodge an appeal. The company said it was examining the court’s ruling in detail.

“Our aim has always been, and remains, to communicate transparently, comprehensively, and responsibly with everyone who buys and enjoys our products,” it added.