1. Gather your ingredients.
* Beef tenderloin (1-1/2 to 2 pounds)
* Kosher salt (1/4 cup)
* Brown sugar (1/4 cup)
* Water (1 gallon)
2. Prepare the brine.
* In a large pot or container, combine the kosher salt, brown sugar, and water. Bring the mixture to a boil over medium heat, stirring occasionally to dissolve the salt and sugar.
* Let the brine cool completely.
3. Place the beef tenderloin in the brine.
* Once the brine is cool, place the beef tenderloin in the container. Make sure the tenderloin is completely submerged in the brine.
* Cover the container and refrigerate the tenderloin for at least 8 hours, or up to 24 hours.
4. Remove the tenderloin from the brine.
* After the tenderloin has brined, remove it from the container and discard the brine.
* Rinse the tenderloin under cold water to remove any excess salt.
* Pat the tenderloin dry with paper towels.
5. Cook the tenderloin.
* You can cook the tenderloin in a variety of ways, such as grilling, roasting, or pan-searing.
* For best results, cook the tenderloin to an internal temperature of 135 degrees Fahrenheit for medium-rare or 145 degrees Fahrenheit for medium.
6. Enjoy!
* Your brined beef tenderloin will be tender, juicy, and flavorful.
* Serve it with your favorite sides, such as mashed potatoes, roasted vegetables, or a salad.