Posted in baking, dry heat

Hydration Levels in Bread: An Exploratory Study

Introduction

As is widely noted in the literature, the hydration level of a dough affects several properties of the resulting bread, most notably hole size. However, preferred hydration levels for certain types of bread are not agreed upon with much precision. One reason for this uncertainty in the field is that hydration level affects different flours differently (see for instance http://www.artisanbreadinfive.com/2008/02/10/qa-flour-and-water). Having recently been burned by this imprecision, the author undertook the following study to offer concrete data on the affects of a variety of hydration levels on King Arthur Unbleached Bread Flour.

Method

This study manipulated one factor, water content, which was measured in baker’s percentage, the ratio of the ingredient (water) to flour, by weight. The factor had four levels: 60%, 70%, 80%, and 90%.

The water was brought to 100F and mixed with 3/4 tsp (approximately 1 baker’s percent) of active dry yeast in a non-metal bowl. This mixture was left for 10 minutes to allow the yeast to become active. Then 200g of flour was mixed in until none of it was dry, to the extent that this was possible. The 60% dough was unable to incorporate all of the flour with the mixing method utilized; this was likely due to experimenter error as even drier doughs have been recorded in the literature. The results of this step are shown in Figure 1. All doughs had an internal temperature upon mixing of approximately 75F in a 62F room.

mix_collage
Figure 1. Doughs upon mixing. From upper right, clockwise: 60%, 70%, 80%, 90%.

The resulting mixture was left to autolyze for approximately 20 minutes. During this time, the flour absorbs water, which then allows enzymes in the flour to break down some of the starches into sugars. The yeast feed on these sugars and multiply before the addition of the salt, which limits their growth. The absorption of water by the flour also makes the dough feel drier, which is helpful for working with higher hydration doughs. After this pause, 3/4 tsp (approximately 2 baker’s percent) was incorporated into the dough. The results of this step are shown in Figure 2.

autolysis
Figure 2. The doughs after autolysis. Clockwise from upper left: 80%, 60%, 90%, 70%.

The dough was then left to ferment for 2-3 hours, until doubled in size. Approximately every half hour, the dough was stretched and folded as described in Robertson and Wolfinger (2010).

An exception was made to this method for the 60% dough, which would be less likely than the others to develop and organize its gluten in the later stages (as the method used here was developed for higher hydration doughs). It was kneaded for a few minutes, short of fully developing the gluten. In contrast, the 80% and 90% doughs developed gluten to the point of showing translucent windows with only these occasional folds.

gluten_windows
Figure 3. Translucent “windows” show effective gluten development in the 80% and 90% doughs. These took little to no effort to stretch (the 80% one was created by accident when a the dough stuck to the author’s finger) and no kneading.

When doubled, the dough was preshaped into a boule, with focus on creating some surface tension on the top of the boule. During all steps, the dough was covered with plastic wrap, but from preshaping on a layer of olive oil was added between the dough and the plastic wrap to prevent rupture of this top layer upon removal of the covering.

The dough was then rested for 30 minutes and shaped again. This began the phase of proofing, which varied in time. When available, the proofing dough was inverted into a floured banneton to support the boule’s shape. Proofing was considered to be finished when the dough slowly recovered from being poked; unfortunately, successful proofing did not guarantee an available oven and the 90% dough may have been overproofed while waiting for space.

When ready to bake, the oven, containing a tagine, was preheated to 500F. The dough was inverted again into the tagine, scored in a square pattern with a lame, and put into the oven covered with the tagine lid. The oven temperature was reduced to 450F (see for example Lahey, 2009) and the bread was baked for 20 minutes. Then the cover was removed but left in the oven to remain preheated for following bakes (see Appendix A), and the bread was baked uncovered for an additional 20 minutes. An exception to this was the 60% bread, which was done after the first 20 minutes and removed. All loaves were cooked to an internal temperature of at least 210F.

The loaf was then removed from the oven and left to cool completely on a wire rack.

Results

We present here the raw, baked data.

60percentprofile
Crust of 60% dough.
60percentcrumb
Crumb of 60% dough.
70percent_profile
Crust of 70% dough.
70percentcrumb
Crumb of 70% dough.
70percentprofile
Crust of 80% dough.
80percentcrumb
Crumb of 80% dough, complete with actual crumbs.
90percentprofile
Crust of 90% dough.
90percentcrumb
Crumb of 90% dough.

Figure 4 shows the relative size of the loaves in ascending order of hydration. Figure 5 gives a bar chart of hydration level by loaf height. As predicted, higher hydration correlated with larger loaves containing larger holes and thus softer crumbs. The hole size did not reach levels found by others with high hydration doughs, which may be due to such factors as fermentation duration and expertise in the techniques of stretch-and-fold, shaping, and scoring.

crusts
Figure 4. Effect of hydration level on loaf size.
barchart
Figure 5. Barchart showing the height of loaves as hydration increases.

Additional differences are observed among the loaves. The 60% bread browned much faster than the others, and its crust failed to develop shine and crackle. This is likely due to the fact that the tagine cooking method, a local variant of the well-known Dutch oven cooking method, relies on the bread’s own steam being released inside the cooking vessel. The low hydration dough would have released less steam than the others, failing to regulate the temperature inside the vessel, so that browning was possible even while it was covered. The lack of steam failed to make the crust glossy, an effect of starch gelating in the presence of water. However, there was still too much moisture to allow the crust to fully dehydrate, so it did not get crisp or make the characteristic crackling noises upon cooling that signal a superior crust.

Grigne width increased as hydration increased, while ear height (never especially high) decreased. Loaf height increased and then decreased as hydration level increased. However, we found that a confound was introduced during experimentation. Doughs were mixed in ascending order of hydration, and despite being spaced out in time to some degree, they were often ready to be baked before their predecessor had left the oven. Meanwhile, the room was heating up, accelerating the rate of yeast activity and thus proofing. The last loaf was therefore likely overproofed. Its reddish crust corroborates this, a sign that much of its starch had been converted to sugar, which is used in a browning reaction. This overproofing would contribute to a lack of height and ear development, so we cannot conclude that its hydration level is to blame.

Discussion

The crust of the 60% dough suggests that for lower hydration doughs, an additional source of steam is needed. Its crumb, however, was excellent for a dense bread, indicating that the difficulty of developing the gluten was not a barrier to good bread. This surprised us, as we were completely ready to sacrifice the 60% dough to the compost bin gods.

Nor was the high hydration level of the 80% and 90% doughs a barrier to working with them, contra some accounts in the literature. Higher protein flours, like King Arthur Bread Flour, absorb more water than lower protein flours such as all-purpose flour, so reports that 90% hydration dough is a pain in the ass may be due to poor flour choice. The 80% dough in particular was reported to be “a fucking delight” by one lab technician, who is also the PI and sole author.

The primary contribution of this work is to show concretely the textures of both dough and final product that can be expected at these landmarks in hydration space when working with King Arthur Bread Flour. However, these findings are not comprehensive, as these doughs were subject to short fermentation times relative to current trends in artisan baking, and were executed by an experimenter who has not actually read the books on which this recipe was based. Regardless, the predicted trends were supported by the data: higher hydration appears to cause greater oven spring and more open crumb structure.

Conclusions

We conclude that 80% hydration is an excellent ballpark for those desiring oven spring and open structure in breads made with King Arthur Bread Flour. We cannot generalize from these findings to other flours, as their different protein and ash contents would make the hydration levels map onto different outcomes.

Additional research is needed to further improve oven spring. We suspect that a large factor is the difficulty of scoring soft doughs, but additional factors are of great interest. Similarly, a followup study on proofing levels of high hydration doughs (see https://forums.egullet.org/topic/82234-demo-proving-bread/) would be useful to determine what heights the 90% dough is actually capable of.

Appendix: Importance of Lid

In a pilot study, we found that when the lid of the cooking vessel is removed from the oven during the uncovered phase of baking, it cools down, raising the concern that it might crack if replaced into a 500 degree oven for the next loaf. Thus, the second loaf was baked uncovered. As both loaves were from the same batch (of a different recipe than that given here), this provided a controlled study of the effect of covering the dough while baking it. The results were quite pronounced, as shown in Figure 6. Not only oven spring, but also crust texture and color, were affected. Note that flour coverage varies due to unrelated factors. Covered initial baking was found to be a far superior method for wet doughs.

tagine_study
Figure 6. Left, bread baked covered for the first half of baking. Right, bread baked uncovered for the entire duration of baking.
Posted in baking, foam

Daring Baker Challenge: Yeasted Meringue Coffee Cake

The March 2011 Daring Baker’s Challenge was hosted by Ria of Ria’s Collection and Jamie of Life’s a Feast. Ria and Jamie challenged The Daring Bakers to bake a yeasted Meringue Coffee Cake.

Recipe here.

filling station
All ready for my guests to dive in.

I used 545g of bread flour (the recipe gave a range for the amount of flour, and didn’t specify the type), and it was perfect.  The dough started out sticky and wasn’t anymore at the end of kneading.

I changed the shape of the bread/cake.  It was supposed to be rolled into a log and then made into a ring, exactly like the December challenge (especially because I filled my December challenge bread with this method instead of by mixing things into the dough).  I decided I would rather have my friends share the work with me and try something new, so I had a few people over and we each took part of the dough and rolled it up croissant-style: cut into an acute isosceles triangle, put fillings on it, and roll from the short edge to the point.

croissant construction
I decided mine was too big and cut it in two.
constructed croissants
We didn't skimp on the filling.

I’m in a cold climate, and since I was having people over to shape the bread, I wanted to make sure it rose on time.  So for the first rise, I put the bowl of dough in the oven with just the pilot light on.  It worked great.

For fillings, we used meringue, chocolate chips, chopped pecans, and dried cranberries.  Delicious.

I tried to do an egg wash the lazy way: rub some meringue on top.  It came out looking like bread with a little meringue rubbed on top, haha.

finished product
Yum.

I baked mine for about 18 minutes, which is shorter than the recipe says, which is expected given that mine had more surface area, and that my oven is crazy.  My thermometer read about 205F when they were done.

You’re supposed to let bread cool first, but we ate them hot, and they were great!  I had no problems with this dough, so I would definitely use that recipe again.

with lemon curd
The meringue left me with three egg yolks, which is just the right number for making lemon curd.
the inside
Very well-behaved dough.
Posted in baking

Daring Baker Challenge: Cranberry Spice Stollen


The 2010 December Daring Bakers’ challenge was hosted by Penny of Sweet Sadie’s Baking. She chose to challenge Daring Bakers to make Stollen. She adapted a friend’s family recipe and combined it with information from friends, techniques from Peter Reinhart’s book, The Bread Baker’s Apprentice: Mastering the Art of Extraordinary Bread, and Martha Stewart’s demonstration.

The Recipe: I altered the flavors and mix-ins.  I used 1 tsp of cinnamon, 1 tsp of cardamom, 1/2 tsp of allspice, and a 1/2 tsp of nutmeg.  I kept the vanilla and orange extracts.  For mix-ins I used slivered almonds, candied ginger, and Craisins, and I mixed them in differently.

    Mix-ins, evenly distributed
  1. Mix yeast and water, wait five minutes.
  2. Add other wet ingredients.
  3. Add dry ingredients.
  4. Add dried fruit and nuts. (I didn’t yet.)
  5. Knead.
  6. Refrigerate overnight.
  7. Let come to room temperature for 2 hours.
  8. Roll into a big rectangle. (Mine didn’t make it to 16×24 in.  Also, I learned that rolling gluten-full dough on top of wax paper doesn’t work, because it shrinks and pulls the paper with it into lots of crinkles.  It worked so much better on a clean bare countertop.)
  9. My way of mixing in: Put mix-ins on top of rectangle and then run a rolling pin over them.
  10. Roll dough like a jellyroll, starting from one of the shorter sides so you end up with a long log.
  11. Bring the ends of the log together, and fit one into the other.  Shape into a nice circle.
  12. Dough ready for the oven.
  13. Slash the outsides of the circle every 2 inches or so.
  14. Let rise for 2 hours.
  15. Bake for 40-50 minutes at 350F, rotating pan halfway through, until bread is 190F.
  16. Cool.
  17. Brush melted butter on top.
  18. Sift powdered sugar on top.

My method of mixing stuff in was probably nicer to my hands and the gluten since there weren’t slivers of almond involved in the kneading.  But I did seem to underestimate how much to use.  I guess the bread rose enough that the amount of mix-ins got diluted.  It was good, though, and the flavors were not at all overpowering.  In fact, I wish I had tasted more cardamom.  But it was a really fun challenge, to make something so seasonal and have it come out looking like it should.  Happy holidays!

Posted in baking

Fresh From the Oven Challenge: Brioche

loaf of brioche
I still have yet to master slashing.

I’m really late posting this, because I was traveling and then, well, not in a blogging mood.  But the August FFTO challenge was really great, I would make this again in a heartbeat. Chele from Chocolate Teapot gave us this recipe from from the River Cottage Handbook No.3 – Bread.

  • 400g strong white bread flour, plus extra for dusting
  • 5g powdered dried yeast
  • 10g fine sea salt
  • 90ml warm milk
  • 2 tbsp caster sugar
  • 100g butter, softened
  • 4 medium free range eggs, beaten

To Glaze

  • 1 medium free range egg
  • 2 tbsp milk
  1. Mix the ingredients.
  2. Knead for about 10 minutes, until smooth and shiny.
  3. Cover and refrigerate overnight.
  4. Shape into two loaves.
  5. Let rise 3-4 hours, until doubled in size.
  6. Preheat oven to 200C/400F/gas mark 6.
  7. Beat egg and milk together for the glaze.
  8. Put loaves on baking sheet.
  9. Glaze loaves with a pastry brush.
  10. Bake 10 minutes.
  11. Turn oven down to 180C/350F/gas mark 4 and bake 30 minutes or until golden brown.
  12. Cool.

Makes 2 small loaves

I actually followed the recipe exactly – shocking, I know – and it worked beautifully except that my stupid oven burned the bottoms of the loaves.  I seriously have to cook everything in it for ten minutes less than recipes say.  The rest was fine, though.  Even though it looks long, this recipe is really easy.  It’s a great one to try.  This was my first time doing a real glaze and I loved the shininess!  It’s just a shame that I left town right after making it so I couldn’t enjoy it more, but don’t worry, I packed one loaf in my carry-on and took it to the friends I was visiting!

crumb of brioche
It was nice and soft, but don't overbake yours like I did!
Posted in baking

Fresh From the Oven Challenge: Turkish Pide

unbaked pide
I took to pinching the corners to get them more squared off.

That’s right, I couldn’t help myself.  I joined another monthly baking club: Fresh From the Oven.  This month, Pei Lin a.k.a Mrs Ergül hosted.  She chose a recipe from Iffet’s blog My Turkish Kitchen for a Turkish bread called pide – sounds like pita, looks not entirely unlike focaccia.  I made mine whole wheat because that’s the only kind of bread flour I have around, and it worked just fine.  Mine looks very, hm, rustic, but I got the basic shape with the scoring and the sesame seeds.  The inside was soft and evenly risen, with small holes throughout.  I think it would be best with some sort of jam or butter, but I had my Turkish friend Seda over (she helped me put together my croquembouche last month), and she liked it without.  She said it was good with a Turkish yogurt drink but she didn’t have a blender to make it with. Here’s the recipe with my notes, and the directions in my own words.

4 cups (to 5 cups) All Purpose Flour – I used 4 cups
1 and 3/4 cups Warm Water – I used 1 1/2 cups
1/2 stick Butter ( melted )
1/2 tablespoon Instant Yeast – I used active dry
1 tablespoon Sugar
1/2 tablespoon Salt
Black and White Sesame Seeds – I only used black

    baked pide
    It didn't rise in the oven as much as I would have liked, but that didn't compromise its texture.
  1. Mix dry ingredients and then add and mix in wet ingredients.  (Not the sesame seeds, of course.)
  2. Knead.
  3. Rise for about 2 hours, until doubled in size.
  4. Fold, then let rest for a few minutes so it will be easier to stretch.
  5. Stretch dough into a large rectangle on a cookie sheet. (The original recipe has measurements, which I ignored. I’m a rogue like that.  I made the rectangle close to the size of my cookie sheet, but not touching any of the sides.)  Score in a square pattern.  Sprinkle sesame seeds on top.
  6. Preheat oven to 350F and let rise 30 minutes.
  7. Bake 30 minutes.
  8. Cool 20 minutes.
close-up
I like the way the black sesame seeds look on it.

The dough had a high hydration level (around the level of ciabatta bread, that famously wet dough) even with my reduction in the amount of water, and yet I found it very easy to work with.  I would definitely make this recipe again, and try it as more of a regular loaf.

a slice
It was nice and fluffy inside.
Posted in baking

Yeast-risen donuts, or how I learned to stop worrying and love cornstarch

I have some European friends whose estimation of the USA rose immensely when they discovered Krispy Kreme Donuts.  They made up a song about them:

I have a hole

In the middle

And I’m glazed

All a-round!

Whenever a new international student would arrive in Atlanta, we would ceremoniously take them through the Krispy Kreme drive-thru in the middle of the night (“We can get donuts now? Without even leaving our car?”) and have them try The Proof of Existence of God.  They were all duly impressed.

Imagine my distress upon moving to Massachusetts, a Krispy Kreme-less wasteland but otherwise lovely state.  I had always thought to myself, as a person who grew up having Krispy Kreme donuts every Sunday (well, every Sunday that I got up early enough to go to the morning church service), a person who remembers when the local Krispy Kreme burned down, a person who once nearly got in an accident trying to change lanes upon seeing the Hot Now sign, that donuts were one food I need never learn how to make, because the perfect donut already existed.  Alas, now it’s up to me.

I didn’t attempt donut making until my friend threw a Hannukah-themed party and told us that fried foods like donuts were traditional.  She mentioned lots of other things, but I knew my calling. I decided to go for a Krispy Kreme copycat recipe by the 99 Cent Chef, which I doubled.

I thought 3/4 cup of milk per batch sounded like a lot, but I shrugged and went on.  Turned out that was probably one of those moments when I should have listened to my instincts.  My dough rose beautifully, but it wasn’t actually dough.  It was definitely batter.  Rolling it out was unnecessary; cutting out shapes was impossible; picking them up and dropping them in oil was laughable.  So I started adding flour – cake flour, so it wouldn’t get too tough from an excess of gluten.  The flour wasn’t helping much, so I started adding cornstarch.  Lots of it.  Cornstarch is great stuff.  I think it’s really underutilized by average home cooks.  You know when you try to sprinkle flour on wax or parchment paper before putting a dough on it?  But you just end up with specks or streaks of flour and then a lot of uncovered space?  If you spread out cornstarch, it actually spreads.  And it turned my batter into a dough, slowly but surely.  It was still plenty sticky, but having tried to make ciabatta bread, I knew that good things rarely come of doughs that are actually comfortable to handle.

I cut out the donuts with my roommate’s cookie cutter and I cut the holes with the top from my bottle of canola oil, which was about the right diameter but not really high enough.  Speaking of which, the dough didn’t rise as much the second time as I had hoped; maybe the yeast were freaked out by everything I was doing to the dough.

DonutThe frying went fine.  I put a bunch of canola oil in my very favoritest stainless steel chef’s pan with my very unfavoritest candy/fry thermometer – unfavoritest because its sensor is higher up on the thermometer than anything I make ever reaches to, so I had to use extra oil just to get a decent reading. (This was before my Christmas present!)  I kept it in the ballpark of 180°F, which was probably a little high, but it seemed to keep things bubbling fast like I wanted.  That’s supposed to mean your fried foods won’t turn out too greasy.  My stove is, like my oven, overzealous, so I had to constantly turn it off and on to keep the temperature in the right ballpark.  I used a metal slotted spoon to handle the donut holes and unpainted chopsticks to handle the donuts (after putting them in with my hands, and a lot of difficulty).  I read about the chopsticks online, and it is brilliant.  I don’t know how else I would have managed.

The donuts came out a deep golden brown, soft on the inside, and a little denser than Krispy Kremes.  I wouldn’t quite put them in the same category as Krispy Kreme donuts – the search is still on – but I’d say they’re yummy fritters.  Maybe less egg would be closer; maybe a better second rise would have helped, too.

Ginger and Cranberry Glazes
You can see some pieces of candied ginger left in the syrup.

I served them with ginger glaze, aka the syrup left over from when I candied ginger, and cranberry glaze, aka the fondant diluted with cranberry sugar syrup that I made for my meringue cookies.  My friend Claire, who adores ginger, thought ginger donuts were an excellent idea.  I was just happy to get to use more of those glazes up.

Posted in baking

Hello there

You know those cooking blogs that have beautiful picture after beautiful picture of perfectly executed pastries and a French word in the title?  This is not one of those blogs.  I love to cook, but like most real people, things don’t always go as planned.  Hence the word “adventure.”  That’s a euphemism for “WTF, the jar of yeast said ‘refrigerate after opening’, so I did, and now it’s totally inactive”.  Which is tonight’s culinary adventure!

Since moving a couple weeks ago to start grad school, I have resolved to cook myself dinner on a regular basis, despite the fact that I am only one person and cooking for one person is less than inspiring.  Not to mention challenging if you dislike wasting food as much as I do.  So the other night I made Leftover Pizza, the toppings of which were the remains of all the food I had been eating during the week: asparagus, bacon, goat cheese, and canned diced tomatoes (which I blended for the sauce; I don’t like regular tomato sauce).  I made the dough from an authentic Italian recipe that is probably not very different from any other recipe you might find, which goes a little something like this (for 2 pizzas):

100.0 B%    198.7 g    2 c flour
79.8 B%    158.5 g    2/3 c water
1.6 B%    3.2 g    1 tsp active dry yeast
1.0 B%    2.0 g    1/2 teaspoon sugar
5.1 B%    10.1 g    2 tsp salt
2.3 B%    4.5 g    1 teaspoon oil

(B% means baker’s percentage.)

The dough, however, never rose.  I had an unleavened pizza.  Since pizza is supposed to be flat, this wasn’t so bad.  The fat dense crusts were pretty yummy, actually.  But it was so dense that it was hard to cut without messing up all the toppings.  I would post a picture, as is the custom on blogs about food, but it was not very pretty.  I told you this wasn’t that kind of blog.

But if you won’t be wowed by my culinary prowess and photographic skill, you may yet learn from my mistakes.  Today’s moral is: you must be careful not to kill your microscopic pets before you put them in a 500 degree oven.  Yeast are like lobsters that way.  Everyone says refrigerating yeast is good, so perhaps it just needs to be taken back to room temperature before it’s ready to pump out the CO2.  This website says just that (although I take that with a grain of salt, since the website also seems to say that yeast makes dough sticky and glutinous, which is patently false; the flour and water do that on their own).  Yeast grow best between 50 and 99 degrees F.  Refrigerators are at about 40 degrees F, so my yeast just didn’t have time to warm up and get metabolizing during the very short rise I gave my pizza.  Next time I’ll use warmer water and/or take the yeast out ahead of time.