Comparing Sourdough Fermentation Strategies

I thought it would be interesting to compare four different approaches to sourdough fermentation. I've baked four test loaves, each with 500 grams total flour (using a 50/50 blend of Heartland Mill Strong Bread Flour and Heartland Mill Golden Buffalo for a blended ash content around .85%), 72% overall hydration, and 2% salt. All loaves started with 18 grams 80% hydration white flour storage starter.

Flour Milling Lab Results

In order to fine tune my milling and sifting process, I ran a series of tests at different mill coarseness settings to see which setting might result in the best separation of bran from endosperm. I then ran a successive reduction multi-pass milling and sifting process at what appeared to be the best first pass settings and sent samples of all these tests to CII Labs to see what some of the ash content, protein content, and dough rheology might be. I also sent in some samples of Heartland Mill flours to use as a reference, since these are the types of flour I would like to emulate with my home milling process. In fact, I use Heartland Mill Hard Red Spring Wheat Berries in all these milling tests.

Accidental Sourdough Starter

As I conducted my home ash content tests during the latest home milling and sifting session, a sourdough starter was accidentally started. The home ash content test involves mixing 5 grams of flour with 100 grams of distilled water, stirring it periodically, and measuring the conductivity of the water until it stabilizes, about 24 hours later. All of that time was spent at about 69F, the temperature of my kitchen in the winter. I noticed a familiar smell, something like yogurt, that was reminiscent of the early stages of some of the starter starting experiments I have conducted in the past. The pH was measured and, sure enough it was around 3.4 for all the jars I was testing, even though the jars had various flours including Heartland Mill AP, Golden Buffalo, and whole wheat, as well as various flours from my milling and sifting experiment.

Home Milled and Sifted Sourdough

Home Milling and Sifting - Two More Tries

Below is a photo of my third attempt at home milling and sifting, which resulted in a flour very similar to my favorite "high extraction flour", Heartland Mills Golden Buffalo flour. The processes used on my second and third tries are explained further below. Additional photos of the process have been posted.

Cream of Wheat Middlings Breakfast

My home sifting project resulted in "middlings", a term I may be using incorrectly. What I mean by middlings is the stuff I sifted out that is finer than bran but was coarser and darker than I wanted for the flour being produced.

Home Ash Content Measurement

Recently, I've been attempting to grind and sift my own flour. The grinding is straightforward with a Retsel Mil-Rite, an excellent home stone buhr mill or my new Meadows 8-inch stone mill. However, the mysteries of sifting the flour have been less straightforward. A subsequent blog entry will deal with my progress on grinding and sifting my own flour. The sifting project motivates the need for measuring the ash content of my flour.

Sourdough Rise Time Table

I've had a number of discussions with TFL participants recently about sourdough rise times versus temperature and inoculation. Temperature has a big effect on sourdough rise times, and sometimes a starter appears unhealthy, when it is really just rising more slowly because of low temperatures in the kitchen during winter. Also, recipes that used to work seem to fail during the winter, but the colder temperatures may be the cause. To adjust for cold winter kitchen temperatures, either the temperature must be managed actively (oven with pilot light or electric light, coolers with a bowl of warm water in them, and so on), or the percentage of fermented flour must be adjusted in the recipe, or much more time must be allowed for the bulk fermentation and proofing.

Home Milled High Extraction Sourdough Miche

100% Whole Grain Sourdough Hearth Bread

Workhorse Sourdough

Miche with Spelt and Rye Levain

Two Sourdough Focaccias - Raisin and Savory

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I spent the day making a couple of sourdough focaccias and a miche that is similar to the Thom Leonard Country French recipe in Artisan Baking by Maggie Glezer. The recipe for the focaccias follows.
A spread sheet in xls format and html format for the dough is posted, which has amounts in ounces and bakers percentages, percent of fermented flour and other possibly useful information. Some photos of the process are posted, as well.

Pane Casareccio e Lariano di Genzano

Daniel Leader's Local Breads has a fascinating story of his visit to Genzano, where he saw them make large, almost charred looking, bran dusted breads raised with a biga naturale, an Italian firm sourdough levain. I enjoyed hearing about his visit with Sergio, while they mixed, raised, and loaded 64 very large loaves into a wood-fired oven. Now that I have a brick oven in my back yard, I thought I'd give a try at making these loaves in the size he says he observed at the bakery he visited. He says they created approximately 8 pound loaves that were loaded eight at a time into an eight foot long by one foot wide by about 4 inches tall box with divisions in it for eight loaves. Thanks to Zolablue for doing this recipe as shown in Leader's book and writing about it in her blog, which provided inspiration as well as lots of information and photos.

Whole Wheat Mash Bread

NYT No-Knead Sourdough Conversion

I haven't tried the NYT No-Knead recipe, although I've read some of the discussions on The Fresh Loaf along the way. Based on some questions from KipperCat about the amount of starter that should go in a sourdough conversion of the recipe, I decided to give converting this recipe to sourdough a try.
I've tried to stay very close to the recipe in The New York Times, although I did a few things differently - some good, some bad, probably.
I have some photos of the process and also a spreadsheet in html or xls format.
Ingredients

• 15 grams (1/2 oz, 1 tbsp) of 90% to 100% hydration white flour starter or 12 grams of firm Glezer style starter or similar.
• 346g (12 oz, 1.5 cups) water
• 450g (16 oz, 3.25 cups) bread flour, should be stronger flour if possible.
• 9g Salt

Mix
Mix water and starter and stir vigorously until starter is fully dissolved. Mix flour and salt to fully distribute salt. Put flour and salt together and use a dough scraper to work the flour into the water. Continue working around the bowl scraping dough from the side toward the center and pushing it down in the center, until you have a shaggy mass. Do a few "french folds" (I still don't know what to call this technique) as in the video I took, if you want, but this step can be omitted. Place dough in covered bowl to rise at 75F for 10 hours.
At 70F it needs to rise for about 13.5 hours. Or, at 70F, use 45g of starter instead of 15g to have a rise time of about 10 hours. Similarly, at 65F try using about 130g of starter. If using larger amounts of 90% starter, remember to adjust the water down in the final dough. For example, for 45g of 90% hydration starter, reduce water by about 15g or 1/2 oz, and for 130g of 90% hydration, reduce water by 50g or almost 2oz.
As you can see, an important aspect of the sourdough conversion is knowing the temperature and how fast your starter is. The above suggestions for the various temperatures would work for my 90% hydration starter, which would double from a feeding of 10g:50g:50g (starter:water:flour by weight) in 6 hours at 75F. The firm version of my starter at 60% hydration would double in volume in 5.5 hours if you fed it (10g:50g:50g) at 75F. At 70F the respective rise times for 90% hydration and 60% hydration starters would be 8.25 hours and 7.5 hours, respectively.
The dough should roughly double in volume or a little less. It's not too important if it doesn't make it all the way to double, and it's probably better to lean toward stopping the fermentation and moving on to shaping earlier, rather than overfementing the dough.
Shaping
I have a video of my attempt at this. I was not used to the gloppy dough you get after letting it rise without folding for so long, but I pressed forward. Scrape the dough out onto a lightly dusted surface. Fold it over itself letter style, turn 90 degrees and repeat. I then attempted to form a boule, but I found it sticking to me and to the surface, so I turned it upside down and made the boule by gathering the sides in toward the middle and pressing together, as you can see in the video.
Place the round loaf seam down on parchment paper dusted with some regular flour and some semolina or corn meal. Place the whole thing in a "ziploc" big bag, or find some other airtight container for the final rise. Place a bowl of water in with the loaf to create a humid environment to avoid a dry skin on the loaf.
The final rise should take about 2 hours at 75F, 2.5 hours at 70F, and 3.5 hours at 65F.
Slash and Bake
Here again, I have provided a video of my somewhat frightening slashing attempts, as well as of lowering the loaf into the dutch oven.
Preheat the dutch oven to 425F about 1/2 hour before baking.
Slashing is optional. AnnieT suggested that this loaf needs no slashing and cracks on top during baking, resulting in a rustic look. I did slash it, but it's somewhat difficult to do with a wet dough like this. Getting the lame wet helps. A very shallow cut at an angle is less likely to stick.
Be very careful to use thick, heat resistant hotpads or very heavy oven mitts. A cast iron dutch oven preheated to 425F is dangerous to move. Be warned. Be sure to have a place prepared for the dutch oven and the lid that is heat resistant when you remove them from the oven.
Drop the loaf, holding it by the parchment into the dutch oven. Place the lid on top. Place the whole dutch oven back in the oven. I baked it for 25 minutes, less than the recipe states, as I was worried about discovering a small piece of charcoal in the dutch oven if I let it bake too long. It was fine, though, and not even that brown after 25 minutes at 425F. At this point, I should have just left the lid ajar and placed the whole thing back in the oven. However, I removed the loaf from the dutch oven, removed the parchment paper, which was very easy, and placed the loaf on the oven rack. It took only a few minutes for the ears on the loaf to start burning. The internal temperature was about 207F, but as is typical with higher hydration doughs, it was somewhat underbaked. Faced with a choice between burnt ears and an underbaked loaf, I decided to just stop the bake. I like to toast or reheat my bread in the next days anyway, so underbaking it is fine for that situation. However, I would in the future keep it in the dutch oven and hope that with the lid only partially ajar, it would keep it from scorching and allow a longer bake.
Summarizing, bake for 30 minutes at 425F with the lid closed, then place lid so it is slightly ajar to let steam escape, and allow it to bake to a dark golden brown color 10-20 minutes more, probably.
Results
The flavor was excellent. The crust was a little thin and soft, due to my poor decisions during the baking described above. However, it still tastes great and is easily rectified by reheating or toasting. The crumb is what I find typical of higher hydration loaves. The  texture is spongey and light with a moist, cool, creamy feel. This bread reminds me very much of the "Pagnotta" recipe in my blog.

Another Miche

Sourdough Rise Time Modelling and Recipe Calculators

I've posted a spreadsheet that summarizes what I do these days to analyze rise times and to dissect recipes or design my own variations. Below is some discussion and also some instructions for the spreadsheet. Use it as is, and modify it as you like. It may contain errors, bugs, and it is not carefully designed to work on all computers and operating systems. It uses "macros", which you have to enable, and it probably will only work with relatively recent versions of Excel that would be available in Microsoft Office 2003 or later. I notice that I can use the spreadsheet on a Macbook with Microsoft Office 2004 for Mac installed on it.
I've built some models of fermentation rates and rise times over the last few years. There is no science here, just trial and error in an attempt to engineer an admittedly crude but hopefully useful model based partly on observations and partly on what little I can gather from some scientific papers and a few baking books. You can beat me up if you want with general treatises on all the ways this doesn't make sense or can't possibly work or is theoretically completely incorrect. I already am well aware I'm skating on thin ice (or possibly am in a coma under the ice already) in any sort of rigorous intellectual or scientific sense. However, if you want to make some specific constructive suggestions or point out neat ways to get a good handle on this or that factor or places where you think the model gives wrong answers and what should be the right answer, that would be interesting.

Essential's Columbia

Sourdough Bagels Revisited