Add filtered water to a pot and bring to a boil over medium-high heat.
Clean the tomatoes under running water.
Remove the stems from the tomatoes and score them with an X at the bottom.
Gently place the tomatoes in the boiling water for one minute.
Transfer immediately to an iced bath for one minute.
Place the cooled tomatoes onto a paper towel and peel. Try to remove any excess water from the tomatoes.
Transfer the tomatoes into a freezer-safe container (or Ziploc bag) and place them into the fridge.
To thaw: Place the tomatoes on a paper towel and let thaw on the counter at room temperature for two hours or until it softens. Use as necessary for your recipe. You can also thaw them in the fridge, which may take over 12 hours. To thaw faster, run the tomatoes under warm water until it softens.