washed and drained fish were then thoroughly mixed with sea salt and
sugar, at approximately about 150 g and 50 g/10 kg fish respectively,
followed by further mixing with steamed jasmine rice and freshly
minced garlic, at 1000 g and 50 g/10 kg fish, respectively. The mixed
ingredients were also stuffed into the fish bellies. The fish were then
placed into bowls covered with plastic sheets and left at 30 °C for 6 h in
order to initiate the fermentation process. Following this, they were
kept at −18 °C in a container for 6 h after which the fish were packed
in plastic bags at approximately 1 kg of fish per bag. The bags were
pressed to expel most of the air then tied with rubber bands. All the
packed fish from the same production lot were subjected to further
fermentation at 30 °C for 144 h. Plaa-som samples were taken for
chemical and microbiological analyses during the production process
at the following steps and times: immediately after mixing and
stuffing ingredients into the fish bellies, designated as sample 1; 6 h
after mixing, sample 2; after packing and overnight freezing at −18 °C,
sample 3; and every 24-h interval during fermentation at 30 °C for
144 h, samples 4 to 9.