Is It Kosher?
By Rabbi Eliezer Eidlitz — a comprehensive guide to the kosher status of hundreds of common foods, ingredients, and food categories.
Dairy Products
The standard for the designation "dairy" for kashrus purposes is different from the government standard. Many products approved by the government as "non-dairy" are actually dairy according to Jewish law. (See also "Non-dairy products," page 134). A common example of this is "non-dairy creamer." Even when this product is certified kosher, we often will find an O/UD or O/KD, as these products often contains casein, a milk derivative.
Three classes of dairy ingredients exist:
1. Dairy by nature: milk, cream, cheese, butter, etc.
2. Milk derivatives: casein, lactalbumin (see albumin), lactose, potassium caseinate, sodium caseinate, whey. (Lactic acid is pareve unless it is used in a dairy product.)
3. Dairy by contamination from equipment and utensils: many baked goods, chocolates, margarine.
Products that need to be checked carefully because they regularly contain the above ingredients are: margarine, "non-dairy" products, baked goods (cookies, pretzels, cake mixes, etc.), and breakfast cereals.
Dairy foods such as yogurt, sour cream, and whipping cream require supervision. Common problems: gelatin, emulsifiers, stabilizers, flavors, colors.
Products such as sour cream, buttermilk, cottage cheese, and others require supervision. Common problem: rennet and gelatin.