Tartine Inspired Sourdough Baguette

Roasting sesame seeds
Preheat oven to 400F - spread sesame seeds evenly on a rimmed baking sheet 10 min
remove from oven / redistribute - continue to bake until well toasted 10-15 m

Poolish
200 gm all purpose flour
200 gm water (75F)
3 gm active dry yeast
mix well
let stand 3-4 hours at room temp or overnight in the fridge

pour water into mixing bowl
add starter and poolish
stir to disperse
combine the flours in a separate bowl (with barley)
add to the bowl with the water, starter, poolish
mix with hands until there is no dry flour
let rest for 25-40 min

transfer dough to large clear container
moisten with a little water and add salt (and sesame seeds) and mix in with fingers by squeezing the dough
turn (fold) the dough every 40 min for 3-4 hours (gently for last 2 - protect the gas!)

transfer dough to working surface
divide into 2 pieces
work the dough into balls
(add as little flour as possible)
keep working until you have taut, smooth, even surface
let dough rest for 20-30 minutes

let rise 3-4 hours in proofing box (2 hours for milder flavor)

20 minutes prior to baking -
preheat oven to 500f

score the loaves

when the oven is heated:
place the loaves in the oven
immediately reduce the heat to 475
bake 25-30 minutes - until burnished, golden brown