A simple grilled cod with bright lemon and fresh dill
Grilled cod with lemon dill sauce is a weeknight dinner that takes twenty minutes from fish to plate. The cod stays moist because you grill it skin-side down over moderate heat, letting the skin crisp while the flesh stays tender. The sauce — butter, lemon juice, fresh dill, and a pinch of salt — comes together in the time it takes the fish to cook, and the heat of the pan does the work for you.
This recipe works best with cod fillets that are roughly the same thickness, ideally between three-quarters and one inch thick. Thinner fillets cook too fast and dry out; thicker ones need longer heat and are harder to cook evenly on a home grill. If your fishmonger gives you fillets of mixed sizes, ask them to cut them to order.
Key Takeaways
- Pat the cod dry before grilling so the skin crisps instead of steaming, and oil the grill grates well to prevent sticking.
- Grill skin-side down over medium heat for most of the cooking time, then flip only at the end to finish the top.
- The lemon dill sauce is made in a small pan while the fish cooks, using butter, fresh lemon juice, and dill added at the very end so it stays bright green.
- Cod is done when the flesh is opaque all the way through and flakes easily with a fork, usually in eight to ten minutes total.
Preparing the cod for the grill
Start with cod fillets that are between three-quarters and one inch thick, skin on. Pat them completely dry with paper towels — moisture on the surface prevents the skin from crisping and makes the fish stick to the grill. Season both sides generously with salt and pepper just before grilling, not ahead of time, because salt draws out moisture.
While the grill heats, prepare your grill grates. Brush them clean with a grill brush, then oil them well with a high-heat oil like canola or grapeseed oil. A well-oiled grate is the difference between skin that crisps and skin that tears. If you do not have a grill brush, crumple a piece of foil into a ball, hold it with tongs, and scrub the grates with that.
Heat your grill to medium — about 400 degrees if you have a thermometer, or hot enough that you can hold your hand six inches above the grate for only four or five seconds. Cod is a delicate fish and burns easily over high heat.
Grilling the cod skin-side down
Place the fillets skin-side down on the grill and do not move them. This is the hardest part, because the instinct is to fuss. Leave them alone for six to eight minutes, depending on thickness and how hot your grill runs. The skin will stick at first, then release naturally as it crisps. If you try to move them before they are ready, the skin tears and stays on the grate.
While the fish cooks, start the sauce. Melt two tablespoons of butter in a small saucepan over medium heat. Add the zest of one lemon and the juice of half a lemon, plus a small pinch of salt. Let it warm through but do not boil — you want the butter to carry the lemon flavor, not cook it away. Keep the pan off direct heat if your stove runs hot.
After six to eight minutes, check the cod by looking at the sides of the fillets. The flesh should be opaque about three-quarters of the way up from the skin. Flip the fillets gently with a thin spatula, supporting them from underneath so they do not break. Grill the other side for two to three minutes until the flesh is opaque all the way through. The fish is done when it flakes easily with a fork and shows no translucent line in the center.
Finishing the sauce and plating
Just before the cod comes off the grill, add a generous handful of fresh dill to the butter sauce — roughly two tablespoons of chopped dill, or three to four tablespoons if you are using whole fronds. Stir it in off the heat so the dill stays bright green instead of turning dark. Taste and add more salt if needed. The sauce should taste bright and herbal, not heavy.
Transfer the cod to a warm plate, skin-side up so the crisp skin stays crisp. Spoon the lemon dill sauce over the top, letting it pool around the fish. Serve immediately with roasted potatoes, steamed greens, or a simple salad. The sauce will continue to warm the fish as you eat.
Why skin-side down matters
Cooking cod skin-side down first serves two purposes. The skin acts as a barrier between the delicate flesh and the direct heat of the grill, keeping the fish moist. At the same time, the skin crisps and browns, adding texture and flavor that you lose if you flip the fish too early or too often.
The skin also tells you when the fish is ready to flip. As the flesh cooks, it contracts slightly and pulls away from the skin, and the skin releases from the grate. Trying to flip before that happens tears the skin and leaves it behind. Patience here is the whole technique.
Variations and substitutions
If you do not have fresh dill, tarragon works well in the same amount, or use half as much dried dill if that is what you have on hand. Dried dill is stronger, so start with one tablespoon and taste before adding more. Parsley is milder and will not give you the same anise note, but it works if dill is not available.
You can make this sauce without the lemon zest if you prefer a cleaner flavor — just use the juice. Or add a small clove of minced garlic to the butter as it melts, letting it warm for a minute before adding the lemon. Some cooks add a splash of white wine to the pan, which adds body to the sauce without making it heavy.
If you do not have a grill, you can cook this cod in a cast-iron skillet over medium-high heat, skin-side down for six to eight minutes, then skin-side up for two to three minutes. The skin will not crisp quite as much, but the fish will be just as moist and the sauce works the same way.
Frequently Asked Questions
How do I know if my cod is fresh enough to grill?
Fresh cod should smell like the ocean, not fishy or sour. The flesh should be firm and spring back when you press it gently. If your fishmonger can tell you the catch date, cod is best within two days of landing. Ask them to fillet it for you if you are not comfortable doing it yourself — a good fillet is worth the small cost.
Can I make the lemon dill sauce ahead of time?
You can make it just before you grill the fish, but do not add the dill until the last minute. The dill turns dark and loses its brightness if it sits in warm butter. Make the butter and lemon base, then add the dill only when the cod is almost done cooking.
What if my cod fillets are very thick?
If they are thicker than one inch, lower your grill heat slightly and give them an extra two to three minutes skin-side down before flipping. You can also cover the grill with foil to trap heat and cook the top more gently. The goal is to get the skin crisp without overcooking the flesh.
Why does my cod stick to the grill even after oiling?
The grates may not be hot enough, or the fish may not be dry enough. Make sure the grill is at medium heat and the cod is patted completely dry. Also check that you oiled the grates just before putting the fish on — oil that sits for too long can burn off. If sticking is still a problem, try a cast-iron skillet on the grill instead.
Can I use frozen cod for this recipe?
Yes, but thaw it completely in the refrigerator first — usually overnight for a standard fillet. Pat it very dry before grilling, because frozen cod releases more moisture as it thaws. The cooking time stays the same once it is thawed and at room temperature.