Overall, I preferred sin chang to bang chang. The ones I have notes on ranged from corn and white rice, bringing less sweetness and more refinement than the same farmer's bang chang (3.3). The one made with corn and rice was tarter up front, not dissimilar to an unblended lambic (3.3). From Jakar, a really nice sin chang that smelled alcoholic and funky, but tasted floral, honeyish, sweet and just a little tart (3.2). From Punakha, a favourite, a pale grey example with underripe fruit tartness, wheaty notes, lots of fruit - very refreshing (3.8). Made in the Chumey Valley, an example with barley and wheat was a standout, tart, lemon, lime, wheaty, call that one Bhutaner Weisse (4.0). In the Haa Valley, an appley, tart example (3.4)

I had quite a few examples of bang chang in Bhutan. They were a tart, greyish example from the Haa Valley that was made with wheat, and was 2 months old (3.0). There was a sourish, porridge-like one made from buckwheat in the Chumey Valley (1.6). One made from wheat that came across like a sourish wheaty brew (3.4). One of my favourites was from Tashigang, and was made with wheat and millet, bringin a fairly sweet profile and a lot of acidity with it (3.4). In Samdrup Jongkhar, I have a corn-based bang chang thtat had a lot of corn sweetness, and just a little bit of acidity (3.8). Also from Samdrup Jongkhar was a corn and rice bang chang that was fruity, tart, with a soft body and a touch of alcohol. The score I'm entering is really a bunch of meaningless numbers.

Bottle courtesy of omhper, thank you sir! Looks like orange juice. Smells like some farmer’s feet. Tastes vaguely like his goats. Tart, funky, fruity. On the Tallinn to Helsinki ferry.

Handbottled (thanks omhper!).
Tokorong Bang Chang. Hazy orange juice yellow colour with no head. Aroma is earthy, quite dusty, some mild buttery notes as well with mild farmyard funk. Flavour is a bit zesty with some funky notes as well as quite dry fruity notes. Nicely semidry palate and very refreshing. Surprisingly clean flavours compared to the Sin Changs I had before the Bang Chang round. 7 3 7 4 14.
Deothang Bang Chang. Pale yellow opaque colour, no head. Aroma is lactic, some funky farmyardy and cowpoopy notes. Flavour is citrus, some funk and has a rather mouthdrying palate. Quite refreshing this one as well, even though quite much more funky and farmyardy than the Tokorong. 4 3 5 4 9.
Haa Bang Chang. Very pale but hazy yellow colour, no head. Aroma is citrus, some earth, mild wooden notes as well as some grains. Flavour is floral, mild citrus, some earth, herbs and mild grassy tones to it. Refreshing, and somewhat dry palate. 6 3 7 3 13.

Handbottled (thanks omhper for all of the below ones!).
Chumey Sin Chang. Quite much pale yellow/silvery colour, medium head and somewhat rich carbonation. Aroma is green apples, some rice, mild earth and herbs. Flavour is slightly acidic, but also mild rice, some maize and mild floral notes. 6 3 6 3 12.
Radhi Sin Chang. Hazy yellow colour, with no head. Aroma is lemongrass, some mild wood, yeast and mild herbs. Flavour is wood, some slight alcohol sweetness along with mild yeast and some quite spicy notes to it. 6 3 7 3 13.
Gongkhar Lodge Sin Chang. Pale yellow hazy colour, small head. Aroma is grainy, some buckwheat, mild herbs and an interesting tone of slightly acidic citrus. Flavour is grainy, some slight acidic citrus, mild buckwheat and a rather big lemony finish. This one was actually rather nice and refreshing. 7 3 8 3 15.