What is XXXX flour? A cook in Boston uses "regular flour, 4X" to make pulled noodles.
Something like 00 flour. Very fine? I only suggest this because sugar is sometimes categorized like such. For instance I can't shake calling powdered sugar 10x since my first bakery job. Its 10x fineness from whole sugar is the point I believe.
Just a guess though
He uses cold water and just regular flour, it's XXXX flour, and he's just going to knead it. So, it's all by feel. He adds water 'til he knows it's right.
When he said "regular," I thought he meant supermarket flour. But maybe he meant "just flour and water, no 'ancient Chinese secret.'"
XXXX is an old Pillsbury trademark.
Is XXXX the same as Pillsbury all-purpose (bleached)?
I doubt that - AFAIR all-purpose flour is usually equivalent to H&R flour. On the other hand it used to Pillsbury's common store brand. But there's no Pillsbury anymore so there's no telling what's packed under that brand name.
(see link below) shows that the XXXX flour has 4 grams of protein in a 30 gram serving. That's 13.3% protein - high gluten flour.
"XXXX Patent® Flour Bleached/ Bromated/ Enriched/ Malted
Perfect “all-around” spring wheat bread flour provide excellent results in any type of yeast-raised product. They are ideal for pan breads, rolls, buns, hearth breads and many specialty-baked products."
BLEACHED WHEAT FLOUR, MALTED BARLEY FLOUR, NIACIN, IRON, POTASSIUM BROMATE, THIAMIN MONONITRATE, RIBOFLAVIN, FOLIC ACID.
I see that PIllsbury had XXXX all-purpose flour also. So it all depends on what type of Pillsbury XXXX flour the Boston cook used in their noodles.