The Yellow Serrano is a popular pepper because of its versatility, from using them raw on sandwiches and salads to roasting them as a spicy side. They also make an excellent salsa and homemade hot sauce. Serrano peppers were originally grown in Mexico and have a medium heat level as they average about 10,000 to 23,000 Scoville Heat Units (SHU). Yellow Serranos are hotter than a typical Jalapeno but not quite as hot as a Thai pepper or Habanero pepper. The Yellow Serrano is a great pepper for those who want a higher heat level than a Jalapeno, but don't want the spicy heat of a Tabasco pepper or Charleston pepper. The peppers start off green and eventually ripen to a bright yellow.