Incorrect storage before or after roasting; old oil or other fats used in the roasting.
When nuts are roasted it causes the oils to go rancid. Go for the non roasted nuts, they're better for you!
Using raw nuts in peanut brittle is recommended because they will be roasted during the cooking process and develop a more intense flavor and crunch. If you use already roasted nuts, they may become overcooked and lose their intended flavor and texture in the final product.
Yes, consuming rancid macadamia nuts can make you sick. Rancid nuts may contain harmful bacteria that can cause food poisoning, resulting in symptoms such as nausea, vomiting, and diarrhea. It is advised to discard any nuts that have gone rancid.
The oils in nuts will make any of them go bad or rancid at some point. They are not bad in the sense they will make you sick just taste bad.
The Brazilian nuts in the 2.5 lbs container are rancid.
Nuts don't go stale per se, but they can turn rancid. Most tree nuts, as well as peanuts, have a high fat content. It's the lipids in nuts that "turn" (go bad). Rancid nuts have a soapy, bitter taste.
Pecans, and all nuts, should be refrigerated to prevent their oils from becoming rancid. Also, nuts should be soaked in a salt water solution for 6-12 hours and then dried before eating or storing. This removes the phytic acid layer of the nuts, helps prevent them from going rancid, and improves their flavor. Pecans will no longer have an unpleasant aftertaste and in fact, become sweeter and more buttery tasting. If the nuts are already rancid, you can try soaking and drying them anyway and that will probably help.
Cheastnuts
Like all nuts, pine nuts can go rancid. Always store nuts in the fridge, preferably in a plastic bag with the air squeezed out and the top fastened by a tie or clip. The plastic bag is also easier to store in the fridge than rigid containers.
Not usually, no.
Yes, they contain oil and get rancid if left out.
all of them have a lot of fat but its good for you. also roasted nuts have more fat than raw nuts.