I was also going to mention this: cake flour for it's low protein levels. In determining what you're cooking/baking, the brand matters far less than the actual type of flour.

Cake / 'biscuits' (my idea of a biscuit is a solid thing to dip in tea, how British of me, but anyway) flour: about 8-9g of protein per 100 grams of flour.

All-purpose flour: 11-12 grams of protein per 100 grams of flour.

Bread flour: 13-14 grams of protein per 100 grams of flour.

'Pastas' vary a lot. Italian-style uses high-protein durum wheat, which is about 14g/100g. On the opposite end, Chinese jiaozi (steamed/boiled dumplings) use low-protein content (8-9g/100g) to give a very smooth texture.

I'm curious if flour in the US is sold with such nutritional labeling: protein, carbohydrate, fat, salt, etc, measurements per standardised measure (in the EU and much of the world, this is per 100g)?

Makes you wonder why we don't sell flour by protein content. Meaning, instead of "cake flour", sell "flour, 6% by wheat protein, good for cakes."

Maybe flour producers ought to have to label protein content on the label (even in small text), so that it's easier to find the right flour for recipes.

So this isn't done? Wow.

King Arthur, a reasonably popular brand (sold at Safeway, etc) here in the US does indeed show the % protein on the packaging: https://www.kingarthurflour.com/products/signature-flours/

Most products also show this on the nutritional label.

Yes. See Southern Kitchen.[1]. What matters is the protein content.

- White Lily flour - 9% protein.

- Hard wheat flour - 12% protein

- Cake flour - 6% protein

An equal mixture of cake flour and hard wheat flour is apparently good for biscuits.

Wal-Mart sells the stuff for $0.51/lb, but they're out of stock right now.

[1] https://www.southernkitchen.com/articles/eat/why-southerners...

Indeed: here's a recipe and discussion of protein levels from 11 years ago that talks about White Lily and how to substitute a mix of cake flour and bread flour (and what amounts of baking powder and soda to add to become "self-rising")

http://pinchmysalt.com/how-to-make-the-best-buttermilk-biscu...

There's also pastry flour, which is in between cake flour and AP flour in terms of protein content.