Place the potatoes, onion, and water in a medium pot and stir to combine. Place the lid on the pot and bring to a light simmer over medium heat. Do not boil. Reduce the heat as needed to maintain the simmer. Cook for 10 to 15 minutes, or until the potatoes are easily cut with a fork.
Add the evaporated milk and whole milk and stir well. Bring the chowder to a gentle simmer. Do not boil.
Add the clams and all of their juice. Heat gently for about 3 to 4 minutes, or until the clams and chowder are hot. Remove the pot from the heat and stir in the salt and pepper. Taste and add more salt or pepper if needed.
Break the butter into small pieces and scatter them over the surface of the hot chowder. Let the butter melt without stirring, then sprinkle with a little more pepper and ladle into four bowls. Serve hot with crackers, rolls, or bread.
Notes
For detailed ingredient notes, substitution tips, variations, and step-by-step photos, scroll through the full recipe post.
Use a digital kitchen scale for precise ingredient measurements.
To switch to gram measurements, click "Metric grams" in the ingredients section of the recipe card.
The potatoes and onion may look crowded in the pot, but 1 cup of water is enough.
Whole baby clams are already cooked, so they only need to be heated through. Cooking them too hard, or for too long, can make them chewy (rubbery).
Storage
Store leftover clam chowder in an airtight container in the refrigerator for up to 3 days. Reheat it gently in a saucepan over low to medium-low heat, or at half power in the microwave, stirring occasionally.
I don’t recommend freezing this chowder because the potatoes and milk can become mealy after thawing.