Wood ash

[3] Decomposition of carbonates and the volatilization of potassium (K), sulfur (S), and trace amounts of copper (Cu) and boron (B) may result from increased temperature.

[3] The study has found that at raised temperature K, S, B, sodium (Na) and copper (Cu) decreased, whereas Mg, P, Mn, Al, Fe, and Si did not change relative to calcium (Ca).

In this role, wood ash serves as a source of potassium and calcium carbonate, the latter acting as a liming agent to neutralize acidic soils.

[7] Wood ash can also be used as an amendment for organic hydroponic solutions, generally replacing inorganic compounds containing calcium, potassium, magnesium and phosphorus.

[13] For thousands of years, plant or wood ash was leached with water, to yield an impure solution of potassium carbonate.

[16] However it was not until the invention of the Leblanc process that high quality sodium hydroxide could be mass produced, rendering obsolete the earlier forms of soap using crude wood or plant ash.

[19] Wood ash is sometimes used in the process of nixtamalization, where certain types of corn (typically maize or sorghum)[20][21] are soaked and cooked in an alkali solution to improve nutritional content and decrease risk of mycotoxins.

In eastern North America, nixtamalized corn was traditionally eaten in porridges and stews, a dish that Europeans would call hominy.

[25] In present day, the amount of wood ash content in bread flour, as measured by the Chopin alveograph,[26] is strictly regulated by France.