Rollmops

Ingredients

• 120 g (½ cup)kosher salt
• 946 ml (1 quart)water
• 454 g (1 pound)trout fillets, 1.3 cm (½ inch) thick, from small whole fish weighing 170–227 g (6–8 oz), scaled, skin on
• 473 ml (2 cups)water
• 473 ml (2 cups)apple cider vinegar
• 15 ml (1 tablespoon)sugar
• 8whole cloves
• 8whole allspice berries
• 6whole black peppercorns
• 4dried bay leaves
• 5 ml (1 teaspoon)red pepper flakes
• 16–20cornichons and/or pickled onions, halved as needed
• 30 ml (2 tablespoons)Dijon mustard
• 1 mediumonion, thinly sliced

Instructions

1. 1

   Make the brine

   Put the salt and 946 ml water in a 4-quart container and stir for 1–2 minutes, until the salt dissolves. Add the trout, ensuring it is submerged, then cover and refrigerate overnight.

2. 2

   Prepare the pickling liquid

   Add the 473 ml water, vinegar, sugar, cloves, allspice, peppercorns, bay leaves and red pepper flakes to a 2-quart saucepan over medium-high heat. Stir occasionally and bring to the boil, about 5 minutes. Cool to room temperature, then refrigerate overnight.

3. 3

   Rinse the trout

   Lift the trout out of the brine and rinse it thoroughly under cold running water for 1 minute. Put the fillets in clean, cold water and refrigerate for 1 hour.

4. 4

   Roll the fillets

   Drain and rinse the fillets, then pat them dry. Arrange them skin-side down in a single layer and brush each with mustard. Put a cornichon or pickled onion on each fillet, roll it up and secure it with 1 or 2 toothpicks. Layer the rollmops with the sliced onion in a glass jar or ceramic crock.

5. 5

   Chill and serve

   Pour the chilled pickling liquid over the rollmops, cover and refrigerate for at least 5 hours and up to 2 days. Drain and serve chilled with crusty bread.

What are rollmops?

Rollmops are a northern European style of pickled, rolled fish, traditionally associated with herring. Here, trout takes the place of herring, with a pickle tucked inside each fillet and a spiced vinegar brine around it.

The method works by salting the fish first, then rinsing it before the vinegar stage. Mustard and the crisp pickle add a sharp, savoury contrast to the trout.

Nutrition and macros by portion

The nutrition label shows one serving as written: 65 calories, 6g protein, 2g carbs, 3g fat.

The trout provides most of the protein and much of the fat, while the small amount of sugar and any bread served alongside contribute carbohydrates. Salt is used in the brine, so the finished sodium content can vary with how thoroughly the fillets are rinsed and drained. Pair a serving with vegetables and a modest portion of bread or potatoes for a more complete plate.

The two-stage brine

Salt brine: keep the trout fully submerged overnight so the salt reaches the fillets evenly. Use a container that holds the fish comfortably without forcing it above the liquid.

Pickling liquid: boiling the spices briefly helps flavour the vinegar mixture. Cooling it fully before it meets the fish keeps the process as described and lets the liquid chill overnight.

Rinsing matters

Cold rinse: rinse the fillets under running water for the full minute, then give them the additional hour in clean, cold water. This step reduces the surface saltiness from the initial brine.

Drying: pat the fish dry before adding mustard. A drier surface is easier to brush and roll neatly.

Rolling and layering

Filling: choose a cornichon or a piece of pickled onion that fits the width of the fillet. Halve larger pieces as needed so the roll closes without forcing it.

Securing: place the roll seam-side down and use one or two toothpicks to hold it together. Alternate the rolls with thinly sliced onion in the jar or crock.

Chilling and doneness cues

Chilling time: allow at least 5 hours in the pickling liquid, or leave the rollmops for up to 2 days. Keep the jar covered and refrigerated throughout.

Serving cue: serve the fish cold, with the rolls holding their shape and the onion and pickle still visible. The method does not specify a cooked-fish doneness test.

What to serve with rollmops

Crusty bread is the stated accompaniment and makes a useful contrast to the sharp vinegar and briny fish. A simple salad or plain boiled potatoes can also round out a light meal.

Recipe notes & tips

• Check that the trout is fully covered by the salt brine before refrigerating it.
• Use a clean glass jar or ceramic crock for the layered rollmops.
• Halve the cornichons or pickled onions if they are too large for the fillets.
• Cool the spiced vinegar mixture completely before refrigerating it overnight.
• Keep the rollmops covered and chilled while they sit in the pickling liquid.

Variations

• Choose herring: use herring fillets in place of trout for a more traditional rollmop.
• Adjust the heat: reduce or increase the red pepper flakes to suit your preference.
• Use pickled onions: tuck a piece inside each fillet instead of a cornichon.
• Add more spice: include extra whole peppercorns in the pickling liquid.
• Serve with potatoes: add plain boiled potatoes alongside the chilled fish.

Common mistakes to avoid

• Fish above the brine: make sure the fillets are submerged so they brine evenly.
• Skipping the rinse: rinse for 1 minute, then soak in clean cold water for 1 hour to remove surface salt.
• Warm pickling liquid: cool it to room temperature and chill it overnight before pouring it over the rolls.
• Wet fillets: pat the trout dry before brushing on mustard so it is easier to roll.
• Loose rolls: secure each one with 1 or 2 toothpicks before layering.

How to store

Keep the covered rollmops refrigerated in their pickling liquid and serve within the recipe's stated window of up to 2 days. The recipe does not give instructions for freezing or reheating; serve them chilled.

Frequently asked questions