Shares in Starbucks fell by 5% in after-hours trading on Thursday after the company announced lower profits in the three months to the end of October.
Starbucks says it has programmes in place to help farmers
The world's largest coffee chain made profits of $117.3 million, against $123.7m a year before - a drop it blamed on new accounting measures.
Sales at outlets which had been open for at least 13 months rose 5%.
Demand in both the US and abroad remained "strong", chief executive Jim Donald said.
The firm said that sales of items such as mugs, books and DVDs were helping profits.
While such items have lower mark-up than drinks, they incur have fewer labour costs.
In the US, Starbucks marked the Halloween period by adding a pumpkin spice latte to the menu along with pumpkin-flavoured muffins.