Opekta, Otto’s company, traded in gelling agents with a base of fruit powder. The company intended to help housewives make their own jams easily and cheaply. The recipe book included step-by-step instructions on how to do this.
On 16 October 1933, Miep Gies started working for Opekta. Afterwards, she said that she had tried out several recipes in the first month. As soon as she mastered the recipes, she was allowed to answer customer questions on the phone.