IN recent years, Jews who keep kosher rejoiced when popular foods that had been off-limits gained kosher certification, from Oreo cookies in 1997 to the Tootsie Roll in 2009.

According to Mintel, the market research firm, the growth in sales of kosher products — up 41 percent from 2003 to 2010 and projected to grow an additional 23 percent by 2013 — owes less to the popularity of keeping kosher or to new products than to existing products becoming certified.

Now, as mainstream brands increasingly pitch to kosher consumers, Manischewitz, the 123-year-old kosher brand, is doing the opposite: creating kosher products that also appeal to gentiles.

While Manischewitz items like matzo are popular Passover fare stocked in a supermarket’s kosher sections, new products have no such association.