Though not all sour sausages found on the streets are unacceptable, many make you heave a sigh of disappointment after a first bite. Inside the glistening, perfectly-charred casing is very little meat and lots of garlicky rice, still in whole kernels. Some rather disturbing versions contain abundant cooked rice that tastes strangely of artificial limeade – a telltale sign that the vendor has added citric acid, or something similar, to the paste to create instant sourness without having to ferment the sausage naturally. Getting this type of sausage when you expect a well-made one is akin to being handed a cup of milk which has been curdled with bottled lemon juice when you expect natural yogurt.
Great sour sausages as made by premium brand names and respectable vendors have one thing in common: the emphasis is on the meat as opposed to the rice. It makes a lot of sense as cooked rice – a basic household ingredient in Southeast Asia – is traditionally used to promote the growth of lactic bacteria; its primary function is to act as the catalyst for fermentation. In other words, we’re souring the meat with the rice in order to get the taste of soured meat; we’re not aiming for a rice-filled sausage that tastes of rice wine.
Most Sai Krok Isan recipes follow the traditional method, i.e. they don’t call for any additives. However, in consulting with Bob, I have learned that it is best to use a pure bacterial culture as the curing agent. This method can get the pH of the paste to drop through fermentation to the generally-accepted ideal range of 4.5-5.0 in roughly 48 hours as opposed to 4-5 days in a warm climate as directed by the recipe. The whole process would be just as natural. Tinted Curing Mixture #1 (Pink Salt / TCM #/DC#1) is also added for safety reasons.
For ease of sourcing and use, Bob has recommended Bactoferm LHP (Pediococcus acidilactici & Pediococcus pentosaceus) as the bacterial culture for this particular application. This freeze-dried culture only needs to be diluted with water before being added to the paste and spurred into action by regular table sugar (in addition to the catabolism of carbohydrates via cooked rice in the recipe).
We then played around with different formulae until the Goldilocks of Sai Krok Isan was achieved. After precisely 48 hours of fermentation at approximately 65°-70°F, we have a traditional Northeastern Thai sausage that is not too salty, perfectly soured; it has just the right texture and level of moisture retention. In other words, it is perfect.