They made it by blending goat's fat with wood ash.

他们通过将山羊脂肪与木灰混合制成。

The oldest hearth, discovered at Qesem Cave in Israel and thick with wood ash, is as old as Homo sapiens.

最古老的炉床是在以色列的 Qesem 洞穴中发现的， 上面覆盖着厚厚的木灰，与智人一样古老。