WHAT ARE TREE NUTS?
Tree nuts are fruits that grow with a hard shell such as almonds, pecans, pistachios, walnuts, hazelnuts, cashews, and Brazil nuts.

Nuts are enjoyed as healthy snacks, or used as ingredients in many different food products. They are a source of protein, vitamins, essential minerals, and antioxidants. They are also used to produce spreads and oils. The versatile nature of nuts makes them a major part of the Pesach pantry1.

HOW ARE TREE NUTS PROCESSED?
First, the nuts are cleaned to remove any foreign objects, then the shells are removed and the kernels are sorted from the shells.

In the past, raw nuts were truly raw, but raw nuts are now processed to ensure that there is no salmonella present. In the US, this is legally required for almonds, but the entire US nut market is slowly shifting in this direction. The treatment can be done with heat (using steam or hot water), with propylene oxide (PPO) fumigation (a chemical process that is losing popularity), or with ethanol, in a new process called Neo-Pure sterilization. The raw nuts are sorted and can be packaged whole, peeled, chopped, diced, or ground into flour and packaged.

Roasted nuts do not need to be pasteurized, because the roasting process kills the bacteria. Nuts can be roasted in one of two methods, an oil roasting process where the nuts are fried in oil, or in a dry roasting process where they go through an oven. In both methods, seasonings or coatings can be applied before or after the roasting process.

ARE TREE NUTS KOSHER?
Raw, untreated nuts do not pose any kashrus concerns when coming from dedicated nut manufacturing facilities. Many simple nut products are processed by repacking facilities that process other products and cross-contamination can be an issue, mostly for Passover, especially when dealing with products that are packed into retail packaging.

The pasteurization process is a potential kashrus concern (especially for Passover) when outsourced to a facility that is not dedicated to kosher production. The new Neo-Pure sterilization process that includes soaking the nuts with ethanol, which is then removed, is a kashrus concern due to the kosher sensitivity of ethanol that can be produced from grapes. Most ethanol in the United States is kitniyos but can also be derived from chometz, which makes this, again, a greater Passover concern. There are reports that the pecans can be soaked in ethanol during the processing and therefore have a similar concern.

Roasted nuts have further kashrus concerns. In addition to verifying the kosher status of the oil for oil roasting, the main concern is that dairy or non-kosher additives can be added before the roasting or immediately after the roasting, while the equipment is still hot (above yad soledes bo). This will cause the equipment to retain the dairy or non-kosher status and affect future production on the same equipment, even if the future product does not contain additives. Roasted nuts should only be purchased with a reliable kosher certification.

There has been much discussion in recent years regarding the production process for cashews. Cashews are roasted in their manufacturing countries by small producers (typically Vietnam, India, or Brazil) to remove the shells and toxins. We are not concerned about the use of non-kosher household equipment for this process since the toxic aspect of the process requires dedicated equipment.

Nuts treated with BHA or BHT as preservatives are not Kosher for Passover due to the corn-based carrier used with the preservatives.

Infestation can be a concern in low-quality nuts and nuts that have passed the expiration date. Consumers are encouraged to check the expiration date and pay close attention to the condition of the nuts that they purchase.

All nuts (including raw) from Israel require kosher supervision to ensure fulfillment of the mitzvos unique to food grown in Eretz Yisroel.

1 Contrary to common conception, peanuts are not considered true nuts; they are legumes and there are different opinions if they are considered kitniyos.