Casola Marocca/Marocca di Casola
I’d been wondering lately what to do with a small amount of chestnut flour that was languishing in a bowl in the cupboard when I saw this thread  started by dorothydean  (Thank you Dorothy!) after she’d read about Casola Marocca  on the Slow Food Foundation website.
I brought back around a kilo of chestnut flour from a holiday in Tuscany last October. The holiday had been organised by The Handmade Bakery , the UK’s first Community Supported Bakery (CSB), and included three mornings of baking classes (which turned into more like 3 full days!). We were staying in a villa in Ponte a Moriano, near Lucca, in the foothills of the Alpi Apuane in the north west of Tuscany (Garfagnana region).
October sees the start of the chestnut harvest in the mountains (the chestnut trees only grow above a certain altitude, above the level of the olive groves & vineyards) and on the first day of our holiday we visited the mountain village of Colognora where a chestnut festival was being held. The weather was atrocious, and by the time we arrived (after getting a little lost) the torrential rain had caused the smattering of small food & craft stalls that had been erected amidst the narrow, steep & stony streets, to start packing up. A few hardy souls continued to roast chestnuts, distributing them gratis in soggy paper bags. We were treated to a tour of the Chestnut Museum  by the museum’s director, who unfortunately spoke no English. With long fluid sentences & elaborate hand gestures (translated into curt one-liners by our Australian guide!), he explained the innumerable applications of the sweet chestnut; we’d run out of time before we even got to the culinary uses, but there’s a useful summary here .
In order to make flour, chestnuts are dried over smouldering chestnut wood & old husks, in specially built smokehouses, before being shelled & stone-ground.
There seems to be some dispute over it’s keeping qualities, with some sources saying it keeps well year round, whilst others say it needs to be kept in the freezer. This might be affected by production methods which I believe also vary. Mine has kept perfectly well in the cupboard since October.
In the UK, Shipton Mill  produce a flour from ‘chestnuts [that] are sourced directly from a small hill farmer, Patrice Duplan, who gathers them from the hills in the Ardeche region of Southern France', according to the blurb. In Tuscany we were told that the French use a different method of drying the chestnuts (I forget how - I've got a vague memory it involved paraffin?! – although I'd be surprised if this was the case with the Shipton.
I have also seen it stocked in wholefood shops.
The flour seems very expensive in relation to bread flours, but when compared with other nuts, ground or otherwise, it is very reasonable.
(Thank you both!)
Both recipes were in Italian but had been google translated. I started the mrfrost recipe before seeing Daisy_A’s post but had decided to leave out the commercial yeast anyway.
I didn't have as much chestnut flour as the mrfrost recipe called for, so made up the amount with extra white bread flour. After all the additions, the dough was still dry & crumbly, so I added the potato I had left over & extra milk to make a stiff, sticky but workable dough.
So my modified recipe was as follows:
290g chestnut flour
210g strong white flour (Doves Farm)
110g mashed potato
I only kneaded it briefly after mixing as I figured there wasn’t much gluten to develop. I gave it a ‘fold’ after the first hour - a bit of an exaggeration: the dough had lost a little of its stickiness but was still stiff, so all I did really was to form a slightly smoother, taughter ball than before.
After another hour, the dough had some spring & had lost it’s stickiness. I just tightened up the ball, being careful not to tear the surface, and put it into a floured banneton. I’m not sure what my reasoning was for doing this, it was more an instinctive act! I guess I felt that the dough wouldn’t benefit structurally from any more folds. If I do this again, I might knead just a little longer after mixing until the stickiness is gone & then put it straight in a banneton.
Another 2.5 hours later, the dough had risen only slightly, almost imperceptibly. I was faced with a choice (since I had to go out an hour later): I could either bake it, leave it on the counter for another 4 or so hours, or refrigerate it (if I could find the space, which was doubtful). I decided to bake. I turned out the loaf and scored it with a deep cross, as mentioned in Daisy_A’s post.
I baked in the same way as I usually bake my sourdough wheat breads: on a preheated kiln shelf, starting high (250-60c) with steam (boiling water in tray below) for 15mins, then down to 200c. I checked internal temp after 30 mins (c.60c) & 40 mins (c.75c). After 55 mins, the internal temp was 92c but the bread still felt very heavy & moist. I needed to leave, so I turned the oven off but left the loaf in.
The dough was obviously underproofed & the bake a bit high, but the result was very visually appealing. I don't think the picture gets the colour very accurately: the crumb was quite purple when first sliced (think darker & more purple than walnut bread), with a purple-red-brown crust, which darkened & mellowed overnight to a chestnut brown (go figure!); the crumb colour too was less pronounced a day later.
When I sliced the loaf in half, I was worried that it wasn't quite done & would be gummy like rye can be, but not at all. Although visually, the crumb texture resembles a rye bread, it feels very different to the touch & in the mouth: it's much drier for a start; this might be due in part to the manner of baking, but I also think that the chestnut flour retains less water than rye. I imagine that one reason for adding the potato is to preserve moisture.
The high bake led to a crunchy crust, like a sweet nutty biscuit (I think the milk contributed to this), which is a great contrast to the close textured, almost meaty, crumb. The sweet smoky flavour is terrific & I’ve had some rapturous responses from some friends who tried it.
I had it first with some Manchego, & the following day with a very similar, but more authentic(!), Pecorino Toscano, both hard ewe’s milk cheeses: a wonderful combination. I also made a mushroom soup, using fresh mushrooms & dried porcini, which was also a good accompaniment.
Other suggestions are soft goat’s cheese & (chestnut) honey, and lardo di Colonnata, or any other salty Tuscan (or other) cured meat.
Why not give it a go!