It was that obsession, over 85 years, which drove four generations of the Lea family to turn a tiny fruit shop in Sydney into a multi-million dollar business with 69 retail stores nationally and 700 employees.
The Darrell Lea story started when London-born Harry Lea and wife Esther began making chocolate in the back of their fruit shop in Sydney's beachside suburb Manly.
When the Great Depression hit, Lea bought out a shirt shop in Sydney's CBD and turned it into his family's first confectionery store in 1929.
By the mid 1930s, Darrell Lea was a fully-fledged business with at least 12 stores in Sydney.
With business booming, the Leas opened their first Victorian store in Melbourne's CBD and later transformed a movie theatre into a huge chocolate factory.
As the company expanded, Harry introduced his four sons and daughter to the family business.
But after Harry died in 1957, trouble began to brew.
At the centre of the drama was Harry's grandson Jason Lea, who joined the company as a trainee manager in 1962.
For Jason Lea, chocolate was everything.
He was driven by a potent recipe of family loyalty and ambition to do better than his parents at running Darrell Lea.
"My loyalty is more towards the business," Jason Lea told ABC TV's Dynasties series in 2005.
By the time Jason Lea was managing director in the 1960s, he had three cousins, his son, and brother reporting to him.
But those family ties were not as strong as Jason's desire for business success.
He made both his son Jason Lea Jr and brother Lael Lea redundant, ostensibly for the good of the business.
Neither would visit Jason Lea, suffering from leukaemia, on his deathbed in 2005.
After his death, the company appointed outsiders to run the business.
Around the same time, Darrell Lea was battling a legal challenge by Cadbury Schweppes over the use of the colour purple.
Cadbury had objected to Darrell Lea's use of various shades of purple in its store signage, uniforms and products, but lost its five-year legal fight in the Federal Court.