With these principles in mind, let us go back to the supermarket. The following foods may be purchased before Pesach without the kosher l’Pesach stamp (because the ratio of chametz to non-chametz found in them is likely to be less than 1:60.): Granulated sugar, non-iodized table salt, instant coffee, freeze-dried coffee or percolator drip coffee, tea or tea bags, cocoa and milk.
The following items require no kosher l’Pesach stamp even if purchased on Pesach: club soda, seltzer, fresh concentrated frozen juices such as orange or grapefruit juice, fresh vegetables, plastic tablecloths, aluminum foil, paper plates, plastic spoons and forks, freezer paper, and toothpicks.
The following items always require a kosher l’Pesach stamp: canned and processed juices, fruit drinks, frozen fruits and frozen vegetables, sugar substitutes, brown sugar, spices and condiments, ketchup, mayonnaise, mustard, instant tea, cheese and rennet. This is because they either contain chametz in unacceptable concentrations or because they are processed with chametz machinery. Fresh vegetables and fruit should be washed because they may be sprayed with chametz substances such as oleic acid.