Yes, cashews do undergo roasting as a necessary part of their preparation before they are safe for consumption.
While you might see cashews labeled as "raw" or "roasted" in stores, the term "raw" can be somewhat misleading when it comes to cashews.
Understanding Cashew Processing
Cashews, in their natural state, are attached to a cashew apple and are enclosed within a hard shell containing a caustic liquid called urushiol, the same irritant found in poison ivy. This substance must be removed before the cashew nut is safe to eat.
According to the reference provided:
Cashews are prepared for consumption in one of two ways: raw and roasted. The phrase “raw cashew” is misleading, as all cashews fit for consumption have been roasted once to remove both the cashew shell and the shell's harmful oils. Roasted cashews are roasted a second time to alter or enhance the cashews' flavor.
This highlights a critical point:
- Initial Roasting: All cashews available for sale, including those marketed as "raw," have been roasted at least once. This initial heat processing is essential to eliminate the toxic oils from the shell and make the nut edible.
- Second Roasting: What are commonly referred to as "roasted cashews" undergo a second roasting. This second step isn't for safety but is performed specifically to improve the flavor and texture of the nuts, often resulting in a deeper color and richer taste.
The "Raw" Cashew Misconception
When you buy "raw" cashews from a reputable source, you are purchasing nuts that have already gone through the essential high-heat process to remove the shell and neutralize the urushiol. They haven't been subjected to a second roasting for flavor enhancement, hence the "raw" designation in the marketplace context, but they are not truly raw in the sense of being unprocessed directly from the tree.
In Summary
- All cashews must be roasted at least once to be safe to eat.
- "Raw" cashews have been roasted once for safety.
- "Roasted" cashews have been roasted a second time for flavor.
So, yes, roasting (at least the initial processing) is a necessary step for cashews to be fit for human consumption.