Pareve (from Yiddish פאַרעוו for "neutral", in Hebrew פרווה, and also parve and other variant English spellings) is a classification of food in kashrut (known as kosher in many English-speaking countries) for edible substances that contain neither dairy nor meat ingredients. Food in this category includes all items that grow from the ground (fruits, vegetables, grains, etc.), fish, eggs, and non-biological edible items (such as water and salt).
In colloquial use, the word pareve can ocassionally be used to describe anything that is neither one thing nor another. See 
Halakha (Jewish law) forbids consuming mixtures of milk and meat, consuming milk and meat at the same meal, consuming dairy foods within a period of time after meat which varies by custom, and using the same dishes for both dairy and meat. Pareve foods accordingly can be consumed together with either dairy or meat.
While fish has the status of pareve, the Talmud warns not to consume fish mixed together with meat, and the custom is not to eat both on the same plate. A less common practice is to refrain from eating fish with dairy.
Eggs that have been laid by a chicken are considered pareve because they are separate from the animal and not considered to be part of the animal. But eggs found inside a chicken after its slaughter are considered to be part of the animal and therefore have the status of fleishig. Commercially marketed eggs generally are not taken from slaughtered animals and therefore are pareve.
Halakha requires that common bread must be made pareve and not contain dairy or meat ingredients, since bread is a staple food, and there is a strong chance one may forget the bread contains the dairy or meat ingredients. Bread need not be made pareve if it is made in an unusual shape or consumed on the same day it is made. Even vegetarians are required to refrain from baking non-pareve bread because halakha applies equally to all Jews.
Food that contains only pareve ingredients but that comes in contact with dairy or meat dishes in the home or that is manufactured on equipment also used to manufacture dairy or meat equipment maintains the status of pareve, and may be consumed after eating dairy or meat. However, if such contact is made, it may only be consumed on dairy or meat dishes respectively. Some commercial products that are pareve but have been manufactured on dairy equipment bear the letters DE after the hechscher to let the consumer know the product cannot be consumed together with meat. Still, such an item can be consumed after a meat meal.
Pharmaceuticals taken for medical purposes that contain animal ingredients, while not technically pareve, do not require a waiting period following their consumption, as they are generally swallowed without being chewed and have little contact with the mouth. The laws of kashrut do not apply to pharmaceuticals taken for medical reasons. Vitamins, on the other hand, have the status of nourishment, and therefore, the laws of kashrut must be followed. The laws of kashrut do not apply at all to substances not taken orally.
While kosher households generally have two sets of dishes, one for dairy and another for meat, some kosher households also include a third set of pareve dishes in order to enable pareve foods to be prepared and then later served with either dairy or meat meals.
Pareve in commercial production
Due to the restrictions in Jewish law forbidding combining milk and meat, many food items marketed to kosher consumers are made pareve, thereby modifying traditional recipes and allowing the item to be consumed either with dairy or meat. Common ingredients used as substitutes for either dairy or meat ingredients include soy and tofu, palm and coconut oils, and various vegetables. Meat analogues are used to replace real meat in recipes, and soy cheese to replace real cheese. Some meat analogues (such as those made by Morningstar Farms) include dairy.
The laws of Marit ayin forbid eating a pareve food that appears dairy together with meat or vice versa. However, with the wide commercial availability of such pareve imitations of both dairy and meat foods, today this is permitted.
Margarine is commonly used in place of butter, thereby enabling a lot of baked goods to be made pareve. In 2008, a shortage of kosher for Passover margarine made it difficult for kosher consumers to prepare pareve recipes.
Pareve and vegetarianism
The word "pareve" on a food label may imply the product is suitable for vegetarians, including vegans, but this is not always true. Fish and fish products, like fish gelatin, are pareve, but in general not vegetarian or vegan (is only for pescetarians). Honey, egg and egg products, like mayonnaise and albumen, are pareve (and vegetarian), but not vegan.
Some processes convert a meat or dairy product into a pareve (neither meat nor dairy) one. For example, rennet is sometimes made from stomach linings, yet is acceptable for making kosher cheese, but such cheeses might not be acceptable to some vegetarians, who would eat only cheese made from a vegetarian rennet.
Likewise, some products bearing a vegan certification label do not have the status in halakha as pareve due to incidental contact with dairy ingredients that render the item dairy while still qualifying by the vegan certification as containing no animal products.
Pareve and allergies
Those allergic to dairy foods may find items labeled as "pareve" to be dairy-free, though this is not always the case. Kashrut has procedures by which equipment can be cleaned of its previous non-kosher use, but that might be inadequate for those with allergies, vegetarians, or adherents to other religious statutes. For example, dairy manufacturing equipment can be cleaned well enough that the rabbis grant pareve status to products manufactured with it. Nevertheless, someone with a strong allergic sensitivity to dairy products might still react to the dairy residue, and that is why some products that are legitimately pareve carry "milk" warnings.
- Kosher Food Production By Zushe Yosef Blech, page 201
- 1,000 Jewish Recipes By Faye Levy
- The rennet must be kosher, either microbial or from special productions of animal rennet using kosher calf stomachs.Oukosher.org, Retrieved August 10, 2005.