Trim all visible fat from the beef and place in freezer for an hour or two to partially freeze.
While the meat is in the freezer, combine the Dr. Pepper, sea salt, pepper, and prague powder #1 in a medium bowl or ziplock bag and mix well.
Remove the meat from the freezer and slice ¼" strips with the grain. Cut against the grain for an easier chew. Or skip the freezing phase and use a Jerky Slicer for evenly sliced strips.
Add sliced beef to the mixture and marinate for 8-24 hours in the refrigerator.
After the meat has finished marinating, remove from refrigerator and strain excess marinade.