Rabbi Mordechai Starshefsky

Rabbi Mordechai Stareshefsky resides in Lakewood, NJ with his family. He is a musmach of BMG, having previously learned in Yeshivas Rav Chaim Berlin, The Mir and Brisk. Prior to joining the OU he worked at ArtScroll as part of the team of writers elucidating Talmud Yerushalmi. His focus at OU Kosher is on Baby Formulas, Spices, Vinegars and the Beverage industry. He was one of the editors of the Halachah Yomis book published by the OU.

Biodiesel and Kosher Glycerin: A look at this important fuel and its valuable byproduct

Kosher Glycerin in Demand About 350,000 tons of glycerin are produced in the United States each year. In part because of decreased government subsidies, and certain other economic factors, kosher glycerin is harder to come by than it was previously. Along with using plant-based feedstock, making the refineries kosher, under rabbinic supervision, makes it possible […]

Ethanol: From Corn to Kosher Vinegar

The Midwest is known as the breadbasket of America, thanks to its endless fields of grains. Omaha-based Green Plains Inc., which makes corn-based products, was founded in 2004 and is now the fourth largest ethanol fuel producer in North America, with 11 plants in Minnesota, Iowa, Illinois, Tennessee, Indiana and Nebraska.  With such a large […]

A Closer Look at Sugar

  One of the tell-tale signs of the winter months is the sweet smells of fresh baked goods wafting through the air, be it sufganiyot, hamentashen or even challah. It prompts us to consider a basic food staple – a food so vital, its absence would render many foods almost inedible. It delights the sophisticated […]

Using Sugar on Shabbos and Pesach

Sugar on Shabbos There is a Talmudic discussion whether food which was fully cooked before Shabbos and subsequently cooled may be recooked again on Shabbos. In Shulchan Aruch’s parlance (O”C 318:4), Yesh bishul achar bishul (is there is cooking after cooking), or Ain bishul achar bishul (there is no cooking after cooking)? The Shulchan Aruch […]