Paa

What it is

Paa is a dry starter, a small cake of rice flour that carries the microbes used to start a fermentation. It belongs to a family of dry starters that the Eastern Himalayas use to saccharify starch and to make mildly alcoholic drinks. Pradhan and Tamang place paa, pee and phut in the Arunachal group of that family, beside marcha in Nepal, Darjeeling and Sikkim, and phab in Bhutan.

The source names the Nyshing community as the makers of paa. The same paper also lists the Apatani against pee and the Mongpa against phut, and its own text names the Nyshing and Apatani in a sentence about pee. The attribution of each starter to one community therefore needs a second source before it is relied on.

Making the starter

Pradhan and Tamang describe the method for the whole family of dry starters in the region. Rice is soaked and pounded into flour and mixed with wild herbs and a few spices. The mix receives 1 to 2 per cent of a previously made starter, in powder form, and is shaped into doughs. The doughs are wrapped in locally available leaves and left at room temperature for two to three days. They are then sun-dried for two to three days.

The authors say that the method for paa, pee and phut is more or less similar to that for marcha. The substrate is rice in each case, and the wrapping is a local leaf rather than the fern fronds used for marcha. The paper gives no paa-specific ratio, temperature or duration. Those figures for paa are not in the source, and no home version should be built from the family description.

Microbial community

The survey sampled two paa starters from Lower Subansiri, at about 661 metres. Their moisture content was 11 to 12 per cent, and their pH was 5.1 (range 5.0 to 5.2). Bacterial counts were about 2.3 × 10^7 cfu/g (range 2.0 to 2.6 × 10^7). The authors isolated 12 bacterial strains from paa.

The paa isolates fell mainly within Firmicutes (about 80 per cent) and Proteobacteria (about 20 per cent). Lactic acid bacteria were present in the paa samples, and the survey also recorded Gram-negative bacteria in them, among them Stenotrophomonas maltophilia. The study profiled bacteria only. Its authors note that moulds and yeasts in these starters were examined in other surveys, so a bacterial list says nothing about the saccharifying or alcohol-producing organisms in paa.

Role in fermentation

In the wider Himalayan starters, moulds such as Rhizopus, Mucor and Aspergillus break starch into sugars, yeasts such as Saccharomyces produce alcohol, and some bacteria contribute flavour, antagonism and acidification, as the introduction to the survey explains. The survey does not test those functions in paa. Its finding is the bacterial population, not a proven division of labour inside the starter.

Pee and phut are the starters tied to two named rice beverages, opo and themsing. No beverage is named for paa. Its general description is that rice is fermented into a mildly alcoholic drink of about 4 per cent with these dry starters.

Storage and renewal

Sun-dried starters of this kind are stored in a dry place, and the authors cite earlier work that keeps them for more than a year. The survey's own samples were transported in sterile bags and held in a desiccator at room temperature. Traditional renewal is back-slopping: a portion of the previous starter is mixed into the next batch. The paper gives no paa-specific renewal interval, and it does not say how long a paa starter keeps before it should be replaced.

Safety and limits

The survey reports which bacteria were present and identified them by 16S rRNA sequencing. It does not show that a paa starter is safe to use, and the presence of an organism does not make it a suitable starter. Gram-negative bacteria appeared in some Arunachal starters, and the paper does not assess their role. Smell, taste, bubbling and visible growth do not establish safety.

No home renewal, storage or fermentation instruction for paa is given here. A starter made or kept outside its community practice is a different product, and its safety has not been studied in this source.