Traditional Swedish Senapssill: Creamy Mustard-Marinated Herring

🌍 Cuisine: Scandinavian
🏷️ Category: Appetizer
⏱️ Prep: 20 minutes
🍳 Cook: 0 minutes (plus 24 hours chilling time)
👥 Serves: 6-8 servings (as part of a buffet)

📝 About This Recipe

A cornerstone of the Swedish Smörgåsbord, Senapssill is a beloved classic that balances the briny snap of Atlantic herring with a rich, velvety mustard emulsion. This recipe features a harmonious blend of sharp Dijon and sweet Scanian mustard, brightened with fresh dill and a touch of honey. It is an essential centerpiece for Midsummer, Christmas, and Easter celebrations, offering a sophisticated interplay of sweet, sour, and savory flavors.

🥗 Ingredients

The Herring

  • 400 grams Pickled Herring Fillets (in clear brine (inläggningssill), drained and patted dry)

The Mustard Base

  • 3 tablespoons Swedish Sweet Mustard (such as Slotts Gästabudssenap or Scanian mustard)
  • 1 tablespoon Dijon Mustard (for a sophisticated sharp kick)
  • 2 tablespoons Granulated Sugar
  • 1 teaspoon Honey (adds a floral depth to the sweetness)
  • 1 tablespoon White Wine Vinegar (12% ättika can be substituted if used sparingly)

The Emulsion & Aromatics

  • 150 ml Neutral Oil (canola or sunflower oil; avoid olive oil)
  • 2 tablespoons Crème Fraîche (for a luxurious, creamy finish)
  • 1/2 cup Fresh Dill (very finely chopped, stems removed)
  • 1 pinch Salt and White Pepper (to taste)

👨‍🍳 Instructions

  1. 1

    Drain the pickled herring fillets from their brine and rinse them briefly under cold water to remove excess saltiness.

  2. 2

    Pat the fillets thoroughly dry using paper towels. This is crucial; if the fish is wet, the mustard sauce will slide off rather than coat it.

  3. 3

    Slice the herring fillets into bite-sized pieces, roughly 1.5 to 2 centimeters wide, cutting at a slight diagonal for a professional look.

  4. 4

    In a medium glass mixing bowl, whisk together the sweet mustard, Dijon mustard, sugar, honey, and white wine vinegar until the sugar has mostly dissolved.

  5. 5

    Begin adding the neutral oil in a very slow, steady stream while whisking vigorously. You are creating an emulsion similar to mayonnaise.

  6. 6

    Once the sauce is thick and glossy, fold in the crème fraîche. This provides the signature creamy texture and a slight tang.

  7. 7

    Stir in the finely chopped fresh dill, reserving a tablespoon for the final garnish.

  8. 8

    Taste the sauce. It should be a bold balance of sweet, sharp, and creamy. Adjust with a pinch of salt or white pepper if needed.

  9. 9

    Gently fold the herring pieces into the mustard sauce until every piece is generously and evenly coated.

  10. 10

    Transfer the mixture into a clean, airtight glass jar. Wipe the rim to ensure a good seal.

  11. 11

    Refrigerate the herring for at least 24 hours before serving. This 'maturing' period allows the flavors to penetrate the fish.

  12. 12

    Before serving, give the jar a gentle stir and garnish with the remaining fresh dill.

💡 Chef's Tips

Always use 'inläggningssill' (prepared pickled herring) for this recipe rather than raw salted herring to save time and ensure the right texture. When whisking the oil, treat it like a hollandaise or mayo; if you add it too fast, the sauce will break and become greasy. For the best flavor, use a mix of coarse-grained Scanian mustard and smooth Dijon to provide both texture and heat. If the sauce feels too thick after chilling, stir in a teaspoon of cold water or additional crème fraîche to loosen it up. This dish keeps well in the refrigerator for up to 7 days, but the flavor is peak between days 2 and 4.

🍽️ Serving Suggestions

Serve alongside warm, buttered small new potatoes boiled with plenty of fresh dill. Arrange on a slice of dark rye bread (Rågbröd) or crispbread (Knäckebröd) for a perfect open-faced snack. Pair with a chilled shot of Swedish Aquavit, preferably one with caraway or dill notes. Accompany with sliced hard-boiled eggs and a wedge of sharp Västerbottensost cheese. Include it as part of a traditional festive platter with pickled red onions and sour cream.