Leaching Food - Procedures and Methods

[flyinglentris]

Some food items from the wild state contain toxins. These food can be made edible by leaching out the toxic substances.

The simplest form of leaching is to soak the food items in water. However, it is not clear whether simply soaking in water is sufficient to leach all such food items. Leaching may be done in brines, oils or lye for olives. Olives naturally contain a bitter substance called oleuropein in their skins which is non-toxic and only effects taste.

What food items may require alternate leaching solutions and procedures? Is it sufficient, for example, to leach the tannins out of acorns by soaking in water?

 

[SatNavSaysStraightOn]

I've used acorns previously to make my own acorn flour. it's time and labour intensive as are most of the "older" techniques.

leaching can be one of 2 types for acorns. hot or cold water leaching. both have good points and bad points. depending on how patient you are and what it is that you are after, depends on which technique you'll use. Cold Water leaching is the old method and preserves must of the water soluble vitamins and minerals that hot water dissolves out of the acorns or where hot water denatures them. not all vitamins, fats and proteins are temperature stable. the down side of cold water leaching is the time scale involved, (along with the volume of water required), 2-3 weeks of soaking is needed with water being changed frequently (daily). In areas of the world where streams, brooks and rivers don't run dry, this isn't a problem. Elsewhere, hot water leaching might be a better option, but it is resource intensive and dissolves out water soluble minerals so the nutritional content of the flour will be lower. the colour and flavour will also be affected.

Beech nuts don't actually need any preparation. once shelled, they can be eaten raw.

Sweet Chestnuts need minimal prep. soaking after shelling, then drying if making flour, else just bake them. personally though I prefer to parboil mine before roasting them. I don't find them as dry that way making eating them much nicer.
obviously do not confuse sweet chestnuts with horse chestnuts. I know you personally won't, but it has to be said, horse chestnuts are poisonous and nothing will change that.