Wet storage is therefore an attractive alternative for short term preservation. The storage and transport of algae in a liquid state allows for algae growth and processing at different locations without the need for installing expensive drying equipment at every growth location. Moreover, wet storage will better retain algae viability, which is an important advantage when algae are reared for aquaculture applications. Indeed, only living algae can produce dissolved oxygen and play a role in maintaining the quality and pH of the culture medium [15; 16]. Most studies on the wet preservation of algae focus on lipid stability. Researchers reported that the total lipid content [17] and the fatty acid profile [18; 19] of _Nannochloropsis_ concentrates remained unchanged after wet storage at 4 \({}^{\circ}\)C for at least one month, while the total fatty acid content was constant or increased slightly [20; 21]. However, [PERSON] and coworkers demonstrated that _Nannochloropsis_ lipids are sensitive to lipolysis under these conditions and that free fatty acids (FFA) are formed within a few days during wet storage at 20 \({}^{\circ}\)C [17]. These FFA can cause off-flavor formation, lipid oxidation [22; 23] and are possibly involved in lipid polymerization during algae processing [24]. It is hence clear that lipolysis is a primary concern for the wet preservation of _Nannochloropsis_. Next to lipid quality, the odor, color and microbial load are also important quality attributes when applications in food or feed are envisioned. Surprisingly, there is little published data on the impact of wet preservation on these quality parameters. [PERSON] et al. [21] studied the variation in total marine bacteria during the preservation of _Nannochloropsis gaditana_ for aquaculture purposes. Concentrates incubated at 4 \({}^{\circ}\)C in plastic bags with regular medium and atmosphere renewal could be stored for up to four months and the bacterial load could be kept low by the addition of a mixture of streptomycin sulfate, penicillin G and ascorbic acid. However, other storage setups that can easily be scaled up are preferred for storage on a shorter term and antibiotic-free preservation techniques are desirable. Algae have a strong and specific odor [25], but to our knowledge, little information is available on how this changes during wet storage. Propionic acid and butyric acid, which have an unpleasant odor, were formed during 30 days of anaerobic storage of enzyme-supplemented _Scenedesmus acutus_[26]. It remains unclear whether such metabolites are also formed on a shorter term and when other algae species are stored under different conditions. Against this background, this research aimed to identify good storage conditions for wet concentrates of _N. gaditana_ produced for food or feed applications. The impact of (i) storage temperature, (ii) the way of sealing the storage recipient and (iii) the addition of acetic acid on algae stability was examined. In a first preservation study, the impact on the microbial load was studied and several metabolites that are known to have an off odor were monitored. Only the storage conditions that resulted in minimal formation of putrefying metabolites were evaluated in the next preservation test, where the lipid, FFA and chlorophyll contents were monitored in detail.