Cheilev in Candles

Can one use cheilev as a candle

Shalom!

Thank you for your question.

It is permitted to use non-kosher cheilev in candles for light during the week.

However, one may not use cheilev candles for one's Shabbat candles. As the Shulchan Aruch writes: (OC 264:3,5) “One may only light the Shabbat candles with oil that is drawn after the wick. As such, one may not use pitch, wax, cottonseed oil, tail grease or cheilev.”

The Shulchan Aruch adds that the preferred manner to fulfill the mitzva of Shabbat candles/lights is to use olive oil. It is explained that olive oil is drawn into the wick in an efficient manner and makes for a bright and pure flame. It is permitted to use unfit oils, as mentioned above, as long as the majority content is of a permitted oil. As such, one can mix cheilev with olive oil if the olive oil is the majority. (Mishna Berura 264:18)

The Sefer Chassidim (#272) tells the story of someone who lives an extraordinarily long life and nobody could figure what this person did to deserve it. We are told that the reason for the longevity is because this person never used cheilev to light the Shabbat candles, only olive oil. Furthermore we are told in Sanhedrin 24a, among other places, that those who use olive oil for the Shabbat candles (and ostensibly the Chanuka candles, as well) will merit to have children who are Torah scholars.

I will note that notwithstanding the above, it is completely acceptable to light the Shabbat candles with wax candles nowadays. So too, it is ultimately permitted to light the Chanuka candles with cheilev if need be. (OC 673:1)