General Effect of growing height and placement in an actual seaweed farm in The Netherlands on the taste of Saccharina and Ulva sp. 

zeewaar farm placement of algae growing lines

To find out if and how different growing conditions could have an effect on the taste of seaweed, we tried cultivating 2 seaweed species (Saccharina and Ulva sp.) under different growing conditions.

Saccharnia latissima

We hung the seaweed lines with the Saccharina weeds at different heights in the water and at different distances from the coastline, meaning more and less proximity to turbulence.

Our conclusions for Saccharina latissima:

  • little differences on growth of the seaweed Z1 -> Z3 (proximity to coastline meaning more or less turbulence) or high/low in the water column
  • very little if any effect on proteins/amino acids (at a given time) by cultivation conditions
  • cultivation conditions in the Zeewaar farm had little effects on taste, except taste intensity.
  • In time differences in biochemical composition, not at a given time.

Ulva sp.

For the Ulva seaweed, we went about it a little differently. We tested growing conditions for these weeds in tanks, meaning a more controlled environment and less natural, unpredictable influences. We starved some of these tanks from nitrogen and phosphate supply, some from (sun)light, and grew some under high turbulence conditions (this last set-up sadly failed).

In these experiments, we saw a clear difference in amino acid composition:

... and in taste:

Our conclusions for Ulva sp.:

  • Cultivation conditions have effects on biochemical composition and taste/odour:
    • replete conditions:
      • highest concentration amino acids
      • bitter/grassy taste
    • phosphate-starved:
      • salty taste/chewy

Overall conclusions

Saccharina latissima is highly adaptive (taste / biochemical composition) under different growth conditions. After researching the effect of growth conditions on taste, we also looked at how processing could have an impact on the taste of Saccharina latissima (spoiler alert: processing impacted taste a lot more!)

In Ulva sp. manipulating biochemical composition and taste is possible by controlling nutrient supply.

Overall, for seaweed grown in the open sea, we can conclude that growing conditions might not have the biggest effect, but when we look at seaweed grown in tanks the story changes. Here, you can play with the nutrients to influence the taste. For microalgae, both processing and cultivation definitely have an impact on flavor.