
This blueberry white cheddar grilled cheese sandwich transforms an everyday comfort food into something extraordinary. The sweet-tart homemade blueberry jam perfectly balances the rich, melty cheeses, all encased in crispy buttered sourdough bread.
I first created this recipe when hosting a summer brunch for friends. The unexpected combination of blueberries and cheese had everyone requesting the recipe before they even finished their sandwiches.
Ingredients
- Fresh blueberries provide natural sweetness and create a vibrant purple jam that brightens the sandwich
- Granulated sugar helps create the perfect jam consistency while balancing the natural tartness of the berries
- Lemon juice adds brightness and helps the jam set properly
- Lemon thyme sprigs infuse subtle herbal notes that complement the blueberries beautifully
- Sourdough bread offers a sturdy texture and tangy flavor that stands up to the fillings
- White cheddar cheese brings a sharp richness that contrasts with the sweet jam
- Mozzarella cheese creates that perfect stretchy cheese pull we all love in a grilled cheese
- Butter creates the essential golden crust that makes these sandwiches irresistible
- Flaky sea salt for finishing adds texture and enhances all the flavors
Step-by-Step Instructions
- Make the Blueberry Jam
- Combine blueberries, sugar, lemon juice, and tied lemon thyme in a 2 quart saucepan over medium high heat. Bring everything to a boil while stirring occasionally to prevent sticking. Once boiling, reduce heat to medium low and simmer for 10 minutes, allowing the berries to burst and release their juices. The mixture will foam slightly at first but then settle down. Lower the heat further and continue cooking for another 10 minutes until the mixture thickens noticeably and coats the back of a spoon. Remove the tied thyme sprigs and allow the jam to cool completely before using.
- Assemble the Sandwiches
- Lay out four slices of sourdough bread on a clean work surface. Spread a generous but not overly thick layer of the cooled blueberry jam onto each slice, leaving about a quarter inch border around the edges to prevent spillage during cooking. In a small bowl, combine the shredded white cheddar and mozzarella cheeses, then distribute this cheese mixture evenly over the jam covered bread slices. The cheese works as a barrier to keep the bread from getting soggy. Top with the remaining bread slices, pressing down gently to secure the fillings.
- Cook the First Batch
- Heat a cast iron skillet over medium heat until warm but not smoking hot. Add 2 tablespoons of butter and allow it to melt completely, swirling to coat the cooking surface. Place two assembled sandwiches in the buttered skillet and cover with a lid. This helps the cheese melt evenly while the bread toasts. Cook for 2 to 3 minutes until the bottom is golden brown. Carefully flip each sandwich using a spatula, supporting the top with your other hand to keep fillings in place. Cook covered for another 2 to 3 minutes until the second side is golden and the cheese is completely melted. If the bread is browning too quickly, reduce the heat slightly.
- Cook the Second Batch
- Remove the first two sandwiches and set aside on a cutting board. Add the remaining 2 tablespoons of butter to the skillet and allow it to melt. Cook the remaining two sandwiches following the same process as the first batch. The second batch often cooks slightly faster since the pan is already hot, so watch them carefully to prevent burning.

The lemon thyme in this recipe is truly transformative. My herb garden almost failed last summer except for this one resilient plant, and its subtle citrusy flavor paired with blueberries has become something I crave. Even my cheese purist husband, who initially questioned fruit in his grilled cheese, now requests this sandwich regularly.
The Perfect Cheese Blend
White cheddar and mozzarella create magic together in this sandwich. The cheddar provides sharp, complex flavor while the mozzarella delivers that satisfying stretch when you pull the sandwich apart. For best results, grate your cheese fresh rather than using pre shredded varieties which contain anti caking agents that prevent proper melting. If you want to experiment, Gruyère makes an excellent substitute for white cheddar, offering a slightly nutty flavor profile that pairs beautifully with the blueberries.
Seasonal Adaptations
While fresh blueberries create the most vibrant flavor, this recipe works wonderfully year round. In winter months, use frozen blueberries without thawing them first. The cooking time may increase by 5 to 7 minutes as the extra moisture cooks off. For variation, try substituting blackberries or a mixture of berries for the blueberries. Each creates a slightly different flavor profile while maintaining the sweet tart balance that makes this sandwich special. During peak summer season, using local berries makes an appreciable difference in flavor intensity.
Serving Suggestions
These sandwiches shine as the centerpiece of a casual yet elegant meal. For brunch, serve alongside a simple arugula salad dressed with lemon vinaigrette. The peppery greens cut through the richness of the sandwich beautifully. For lunch or dinner, pair with a cup of tomato soup for a sophisticated take on a classic combination. If serving for a gathering, prepare all components ahead of time and assemble sandwiches just before cooking. Cut into quarters rather than halves for appetizer sized portions that disappear quickly at parties.

Recipe FAQs
- → Can I use frozen blueberries instead of fresh?
Yes, frozen blueberries work well for the jam. There's no need to thaw them first - simply add them directly to the saucepan. You may need to cook the jam for a few extra minutes to evaporate the additional moisture.
- → What can I substitute for lemon thyme?
Regular thyme with a bit of lemon zest makes an excellent substitute. Alternatively, rosemary or basil can work well with the blueberry-cheese combination, though they'll create a slightly different flavor profile.
- → How long does the homemade blueberry jam keep?
The blueberry jam can be stored in an airtight container in the refrigerator for up to 2 weeks. This makes it perfect for preparing in advance or making extra for future sandwiches.
- → Can I use other cheeses in this sandwich?
Absolutely! Brie, goat cheese, or Gruyère would all complement the blueberry jam nicely. The key is balancing a melty cheese with one that has a stronger flavor to stand up to the sweetness of the jam.
- → What bread works best if I don't have sourdough?
Brioche, challah, or a hearty white bread would all work beautifully. The important factors are choosing bread that can withstand grilling without becoming soggy and complement the sweet-savory filling.
- → How do I prevent the bread from burning while the cheese melts?
Cooking the sandwiches covered helps the cheese melt before the bread gets too brown. Using medium-low heat and monitoring closely also helps. Another trick is to grill the bread open-faced until lightly toasted, add the fillings, then finish grilling the assembled sandwich.