In June 1905, Cadbury launched its first Dairy Milk bar, with a higher proportion of milk than previous chocolate bars, and it became the company's best selling product by 1913. George Cadbury Jnr, responsible for the development of the bar, has said All sorts of names were suggested: Highland Milk, Jersey and Dairy Maid. But when a customer’s daughter suggested Dairy Milk, the name stuck. . Fruit and Nut was introduced as part of the Dairy Milk line in 1928, soon followed by Whole Nut in 1933. In 1933 dairy milk went out of production briefly then came back in 1934. By this point, Cadbury's was the brand leader in the United Kingdom. In 1928, Cadbury's introduced the glass and a half slogan to accompany the Dairy Milk bar.
Many of the newer Dairy Milk varieties are now manufactured in the Republic of Ireland, France and Poland. Aficionados[who?] complain that the product no longer tastes as good and has lost its creamy texture. Dairy Milk itself is also manufactured in France and these products are sold in the UK. In early 2006, Cadbury changed the weight of its medium bars from 200g to 250g, effectively phasing out the 200g Wafer bar, as the way it was manufactured did not allow for it to be manufactured as a 250g bar. Several reformulated versions are sold in the United States as the U.S. Food and Drug Administration does not allow products that replace cocoa butter with vegetable fat to be called chocolate.
In Australia, Cadbury Dairy Milk was reformulated in 2006 and again in 2009, with the addition of palm oil as a replacement for some cocoa butter. This occurred in conjunction with a weight reduction of the standard block from 250g to 200g. There has been some outcry over the reduction in block size while the price stayed the same, although Cadbury states that the wholesale cost per gram should be the same and the retailers may not have adjusted their prices. In August 2009, Cadbury announced it would return to a Cocoa Butter only formula due to a poor response from consumers.
Cadbury secured Fairtrade certification for solid-chocolate Dairy Milk bars in the UK and Ireland in 2009, with the first bars bearing the Fairtrade Mark produced on 21 July 2009. The company has since announced plans to roll out Fairtrade-certified Dairy Milk bars in Australia and New Zealand (and by extension Japan) in spring 2010, and in Canada that summer.