Mafuta olemera amatha kuyatsa, komabe kamangidwe kake kowundikiza kamapangitsa kuti ikhale yovuta kuunika ndipo imalepheretsa kuyaka kwathunthu. Komabe, m'malo okhala ndi mpweya wambiri, mafuta olemera amatha kuyaka mosavuta.
Kupaka mafuta, pamene kuyaka, sichiyatsa ikakhudzana ndi lawi mwachangu momwe mungaganizire. Zimagwira ntchito ndi oxidation, yomwe ndi yofatsa kwambiri.