Trim any excess fat off the beef round. If the membrane or silverskin is still on the meat, remove that with a table knife and paper towel.
Slice the beef round into ¼ inch slices. Ensure they are sliced unformly for the best results when smoking.
In a small saucepan over low heat, combine all the marinade ingredients. Allow to cool and transfer beef slices to marinade, covering thoroughly.
Transfer slices to a large Ziploc bag or airtight container. Pour remaining marinade over meat. Place container or bag in yourrigerator and leave to marinate overnight, or for at least 12 hours.
Line a baking sheet with paper towel. Remove meat from refrigerator and transfer to lined baking sheet. Leave to dry.
Fire up your electric smoker to 165°F (74°C). Add wood chips to tray.
Place beef strips on smoker grates and close chamber door. Smoke for 3 hours.
Check the jerky every hour to make sure the pieces are not cooking unevenly. If they are, rearrange them accordingly.
After three hours, remove the jerky from the smoker and leave to cool on cooling rack. The jerky will be done when it is dry and tough, but can bend without breaking.
When completely cooled, store in airtight container in the refrigerator. It can be stored for up to two weeks, but is best enjoyed within four days.