I’ve adapted this from the sturdily reliable pain de campagne recipe on p.108 of 'Surdeig' by Casper André Lugg & Martin Ivar Hveem Fjeld.
I tried many different ratios of sunflower to wheat flour. This one gave the best compromise between the amazing crumb softness and crispy crust provided by the former and the good strength and shape delivered by the latter (quite important given the elaborate scoring).
You don’t have to use a rye starter, a spelt-fed one works just as well, but don’t omit it either. That small amount of rye (or spelt) delivers great depth to the flavour of the loaf.
For the uninitiated, Desired Dough Temperature (DDT) is the temperature you want your dough to be after mixing all the ingredients. It is usually the optimal temperature bracket that yeast needs to ferment most efficiently. All you need to do is add together the temperatures of the flours and levain (a cheap digital probe thermometer does the job very well); then divide by the number of measurements you’ve made to get an average temperature; and finally subtract that average from the DDT. This tells you how much hotter (or colder) your water has to be to bring the dough to the correct temperature. There are more complex and precise ways of calculating it, but this method works very well most of the time.
Don’t get confused by the percentage of salt. A baker’s percentage of two translates to just under one per cent total. Very healthy.
If your levain looks a little under-powered at the time of mixing, just add a gram of instant dry yeast to help the dough along.
The amount of water required will vary with the seasons and with how comfortable you are handling higher hydration doughs. I suggest starting with the lower amount then, during the mix, adding more little-by-little until you achieve the level of hydration you prefer.
If you’re not familiar with the stretch-and-fold technique, it is an alternative way to add strength, elasticity, and extensibility (stretchiness) to the dough. Traditionally this is done by kneading. Save your wrists and learn to stretch-and-fold. It does the same job in a fraction of the time and effort. Master baker Ken Forkish has an excellent YouTube video demonstrating how to do it (for the time being ignore his other videos: Ken has a wonderful but very idiosyncratic bread-making style which won’t work with this particular loaf)—https://www.youtube.com/watch?v=CQHuWDEo3SA&spfreload=10. As the great man says, only stretch until you feel the dough resisitng. This is VERY important.
All that milled sunflower seed makes this a delicate dough. Try your hardest to preserve the cell structure during fermentation and shaping. Always handle it gently and, please, no punching-down, slapping, or tipping out onto a surface from a great height.
Creating steam in domestic ovens can be a challenge. I’ve tried all sorts of complicated, fussy release mechanisms: water over rocks, boiling water, ice cubes etc., etc., but, in the end, a small amount of cold water poured onto a hot, high-sided roasting tray placed on the floor of the oven works as well as any other. Never fill to more than half the depth of your tray—and that’s probably too much. It is also very easy to slide out when it's time to release the steam. So much simpler (and cheaper) than all the alternatives.
By all means use a round cast-iron Le Creuset-style casserole dish (Dutch oven) if you have one. It will work very well with this loaf, but make sure it is pre-heated—cold starts are not a good idea with this amount of scoring.
Levain: 8-12 hours/overnight
Autolyse: 30 minutes
Mix: 2-3 min
Bulk Ferment with Stretch-and-Fold: 2-3 hours with S+F at 15/30/60 mins
Pre-shape: 20-25 min
Proof: 45-60 min (but begin checking after 35 min)
Bake: Preheat to 260/240℃ (fan) then 20 min (under steam) at 240/220℃ followed by 20 min at 220/200℃
Makes one large 900g boule _____________________________________