Overview

Surströmming is a traditional Swedish fermented fish product made from Baltic herring (Clupea harengus). It is known for its strong aroma and represents one of the most distinctive examples of low-salt fish fermentation in Europe.

Raw Materials

  • Baltic herring (Clupea harengus)
  • Salt
  • Water

Fermentation Process

Freshly caught herring is lightly salted and placed into fermentation containers. Unlike heavily salted fish products, surströmming uses reduced salt concentrations, allowing microbial fermentation to proceed. The fish is fermented for several months, often continuing to ferment after canning.

Microbial Ecology

Fermentation is driven by a halophilic and anaerobic microbial community, including:

  • Halanaerobium spp.
  • Lactic acid bacteria (Lactobacillus spp.)

These microorganisms produce organic acids, sulfur compounds, and volatile metabolites responsible for the characteristic aroma.

Functional and Nutritional Aspects

  • Preservation of fish through acidification
  • Partial protein hydrolysis enhances umami flavours
  • Retains omega-3 fatty acids from herring

Cultural Significance

Surströmming is deeply embedded in Swedish food culture, particularly in northern regions, and is traditionally consumed during seasonal gatherings. Its preparation reflects historical strategies for fish preservation in low-salt environments.

References

  1. Lundén, A., & Korkeala, H. (1996). The microbiology of fermented fish. International Journal of Food Microbiology, 30(1–2), 43–60.
  2. Paludan-Müller, C., Madsen, M., Sophanodora, P., Gram, L., & Møller, P. L. (2002). Fermentation and microflora of pla-ra, a Thai fermented fish product. International Journal of Food Microbiology, 75, 69–77.
  3. Steinkraus, K. H. (1996). Handbook of Indigenous Fermented Foods. Marcel Dekker, New York.