After re-reading Tartine No. 3 recently, I got inspired to start experimenting again with super-high hydration sourdough production. My typical hydration for sourdough is 75%, but Tartine goes even past 90% hydration! My earlier forays into 90%+ hydration were a little discouraging. I produced pretty flat loaves that, though possessed of a really open crumb, didn’t have much vertical rise. Then I saw some pictures of full loaves of Tartine and realized they had similar results!

But for me, I wanted to find a balance between extreme hydration and maintaining some oven rise. So I decided to do some tests, of which this is the first. The loaves in the pictures above were made with 85% hydration dough. I have a feeling that that is probably the limit of the type of flour I’m using, but the next bake, I’m going to push it to 90%.

These turned out a lot better than my previous forays. And part of that – I think – is due to the baskets I used. I watched some videos of both Tartine and several other bakers that were making high-hydration oval loaves and they all used what appeared to be 14″ baskets. So I got a couple. I think it makes a difference as it allows the dough to expand. But I won’t be absolutely sure until I make loaves using a standard oval basket and a long basket at the same time.

Baker’s Formula

Flour		100.00%
Water		85.00%
Salt		2.00%
Diastatic Malt Powder (optional)**		2.00%
Total Percentage		189%

Final Dough

Flour 50% Bread Flour (13.8% protein), 30% Whole Wheat, 20% Kamut		935g
Water		775g
Salt		21g
Levain*		267g
Diastatic Malt Powder		21g
Total Dough Yield		2020g 2 X 1000g loaves + 20g wiggle room

The Process

Make the Levain. Like Tartine, I prefer to use a young levain because I like the nutty flavor characteristics of a young levain and prefer to develop sourness during final fermenation. Even if I end up fermenting the dough enough to make it sour, it won’t be overpowering. For this particular recipe, I take about 50g of mature starter (I maintain a separate mother) and combine it with 150g flour and 150g water (warm enough to get my dough to about 80°F). Levain is ready when it passes the float test (anywhere from 2 – 5 hours depending on weather).

Initial Mix/Autolyse. Reserve about 50g of water, then mix the rest with all of the flour (if you’re using diastatic malt powder, add it now so the enzymes have a chance to break down the starches in the flour). When I use whole grain flour, I will typically autolyse for 2-4 hours, in parallel with my levain maturing.

Final Mix. Add all the levain, salt, and reserved water to the dough. Mix thoroughly until all ingredients are fully incorporated.

Bulk Fermentation. 4-6 hours depending on ambient temp or rate of fermentation or until the dough has expanded about 30-35% of its original size. There are a lot of variances in the timing. With the loaves shown above, they took a long time to bulk ferment, even at 80°F.

Divide and Pre-Shape. Divide the loaves into 1-kilo pieces, then work into rounds, developing a little surface tension. Bench rest uncovered for 20-30 minutes until the balls have relaxed.

Shape. Shape into rounds or ovals, then place into baskets.

Final Fermentation. 12-24 hours at 39°-42°F. The longer you go, the sourer the bread. I’ve taken loaves out to 36 hours but by that time, the acids started breaking down the gluten and I didn’t get much oven spring.

Bake. Bake at 475°F for 20 minutes with steam (if using a Dutch oven, then 20 minutes with the lid on). Remove the steaming container, then bake for 25-35 minutes dry at 425°F or until the crust has baked to a deep, golden brown.