A bag of cashews that was crisp two weeks ago and has gone soft, slightly rubbery, or faintly "off" by the time you get back to it isn't unusual — it's actually closer to normal than most people realise. Cashews are one of the trickier dry fruits to keep fresh, and the reason has less to do with the batch and more to do with how it's stored after it's opened.

Why cashews are harder to store than most dry fruit

Cashews run roughly 46-47% fat by weight — higher than most other commonly stored dry fruit. That fat is exactly what gives cashews their richness, but it's also what makes them vulnerable: exposed to heat, light, or air for long enough, that fat oxidises and turns rancid, which is what's actually behind the stale, slightly bitter taste an old bag develops. On top of that, cashews are hygroscopic — they pull moisture straight out of the surrounding air. Leave a bag open on a kitchen counter through a humid week and the kernels will visibly soften, whether or not they were ever mishandled before that.

What "fresh" actually depends on

Industry specification for cashew kernels at the point of packing calls for moisture in the 3-5% range (per the Agricultural and Food Industries cashew kernel specifications) — so a properly graded batch starts out dry by design. What happens after packing is what actually decides how long that holds. Four things drive spoilage from there: moisture, heat, light, and air exposure. Control those four and a batch holds its texture and taste for a long time; leave any one of them unchecked and shelf life drops fast, regardless of how good the batch was on day one.

How long cashews actually last, and where

Once a pack is opened, kept at room temperature in a typical pantry, cashews stay at their best for roughly a month before quality starts visibly slipping. Moved to an airtight container in the refrigerator, that stretches to around six months. Frozen in a sealed container or bag, they last longest of all — the better option for anyone stocking up rather than eating through a pack quickly. The simplest habit that makes the biggest difference: transfer cashews out of the bag they came in and into an airtight jar or container as soon as it's opened, and keep that container away from direct light and away from stovetop heat.

For anyone buying in bulk

The same four drivers that spoil a kitchen jar — moisture, heat, light, air — are exactly what determine shelf life in a warehouse, just at a larger scale and over a longer stretch of time. It's part of why checking the moisture reading on a batch before accepting it matters as much as it does: a batch that starts within spec and is then stored correctly keeps its quality for months; a batch that starts high on moisture, or gets stored loosely once it arrives, loses that quality fast no matter how good the grade looked on paper.