Sorting and Cleaning
Float Test vs Weight Test for Nuts
Short answer: The float test, useful for acorns, and the weight test, useful for most shelled nuts, both sort out light or hollow nuts, but they suit different nuts and stages. Use float testing where it fits the nut, weight and feel elsewhere, and always follow with visual inspection and a test crack.
What should you keep in mind?
- Float test suits acorns and wet sorting.
- Weight suits dry shelled nuts.
- Both need visual inspection afterwards.
At a glance
| Float test | Suits acorns and wet sorting, floaters are usually hollow or damaged |
| Weight test | Suits dry shelled nuts, light or rattling nuts are usually poorly filled |
How this compares
Both tests sort out light or hollow nuts, but they suit different nuts and stages, so using the wrong one wastes the sorting it was meant to do. Float testing fits acorns and wet sorting, weight and feel fit dry shelled nuts, and both need visual inspection and a test crack afterwards. Tests sort, inspection confirms, and neither step replaces the other.
What floating actually tells you
Floating is a useful signal, not a verdict, because a nut that floats is usually hollow, damaged, or poorly filled, yet some sound nuts can float for reasons unrelated to kernel quality, such as trapped air or a light shell. That is why floaters should be set aside for closer inspection rather than discarded automatically, and why sinkers should still be inspected rather than assumed perfect. Treating the test as a sorting aid, rather than as a final judge, keeps useful nuts from being wasted and bad nuts from slipping through on a technicality.
Choosing the right test for the nut in hand
Wet sorting suits nuts that are already wet or that will be processed wet, such as acorns, because the water does no extra harm and the test is quick for large quantities. Dry shelled nuts, by contrast, should not be soaked merely to test them, since wetting creates a drying problem that may outweigh any sorting benefit. Matching the test to the stage and type of nut is therefore a practical skill, and using the wrong test often causes more trouble than the sorting it was meant to achieve.
Reading weight and rattle with practice
A sound dry nut usually feels solid and heavy for its size, while a hollow or poorly filled nut feels light and may rattle when shaken gently near the ear. Learning that difference takes a few comparisons between known good and known bad nuts, after which the hand and ear become surprisingly reliable sorting tools. Weight testing works best in a quiet moment with clean hands, when subtle differences in feel are not masked by noise, haste, or a pile of mixed types.
Inspection after every test, without exception
Neither floating nor weighing can see mould inside a shell, smell rancidity, or reveal insect damage hidden under a sound exterior, so visual inspection and a sample crack must follow whichever test was used. Look for discolouration, holes, cracks, and soft spots, smell the batch, and open a few nuts from each lot to confirm kernel condition. This closing inspection is what turns a rough sort into a trustworthy one, and skipping it leaves the very faults that sorting exists to catch.
Frequently asked questions
Should every floating nut be discarded automatically?
Floaters that look sound on inspection, smell fresh, and open to a full kernel in a sample crack can be kept, because floating alone is not proof of a bad nut. If inspection reveals mould, hollowness, or a shrivelled kernel, discard them without further debate. The test sorts candidates for inspection, and inspection makes the final decision.
Is it worth soaking dry nuts just to float test them?
Yes, soaking dry nuts merely to test them usually creates more harm than good, because the nuts then need thorough drying before storage and may mould if drying is incomplete. Weight, feel, and visual inspection sort dry nuts effectively without any water. Reserve floating for nuts that are wet already or that will be processed through water in any case.
What does a rattling nut usually indicate?
Rattling suggests the kernel has shrunk away from the shell or was never fully formed, both of which point to a poor nut, but a single rattle should still be confirmed by inspection and, if needed, a sample crack. Some kernels rattle slightly while remaining sound, so use rattling as a reason to look closer rather than as an automatic discard. A pattern of rattling across a lot, however, is a strong warning.
Which test works better for a very large batch?
Large wet batches suit floating well, because many nuts can be tested at once and floaters can be skimmed off quickly, whereas weighing each nut individually would take far too long. Dry batches suit weighing, because each nut can be handled and judged without water. Choosing the test that matches the batch size and moisture stage keeps sorting efficient as well as accurate.
What to do next
Tests sort; inspection confirms.