If I use a mortar and pestle for working with candlenuts (who are considered mildly toxic when raw), to make a paste that is later cooked, how thoroughly and how does that mortar (not dishwasher proof, using soap is also best avoided) need to be cleaned before you can safely use it for raw preparations like pesto?
Didn't even know they were toxic uncooked, and survived 40+ years of home cooking (both by me and my parents) without any ill effect, I would say 99% of the times ground uncooked.
That is, however, not an answer, so I will just explain my point of view, and why I won't bother with extraordinary cleansing after grinding candlenuts.
- I can't find anything on the toxicity levels, other than "mildly", and never saw any warning on any bag of candlenuts. I did find it on some other "exotic" ingredients, most notably mustard oil.
- Not a very strong argument, but: Usually, somewhere between 5 and 10 nuts are used, tops. For a mildly toxic ingredient, this seems quite a low number to make it dangerously toxic.
- It seems unlikely to me that after grinding you end up with 99% of the stuff going in to the dish, and yet somehow, a significant, if not most of the amount of toxins remaining in the mortar.
- Recipes sometimes do tell to toast the candlenuts first. None of the ones I know of say it is because of the toxicity. All of the ones I know of, tell to toast them lightly, a few minutes max. Given the size of a candlenut, it seems unlikely to me (but I'm not chemist) that toasting it for around 2-3 minutes will kill the toxins. Come to think of it: None of the books, recipes, or sources otherwise ever even mentioned their toxicity.
- Lastly, and completely irrelevant, I may be the lucky one of course: I'm still here breathing.
All in all, I personally group it into the "Tomatoes and potatoes are toxic" category. Both nightshades, but you'll have to eat a ton of them in one sitting before you'll have to start worrying.