Bread Experiment 1 – Whole Wheat

In case you can’t tell, one of the things I find most enjoyable about baking is that there is a scientific process to the whole thing. Small changes in the underlying formulas and methods produce measurable results. The problem for the home baker is, because we bake so infrequently, we don’t get as much practical experience, or a long amount of time passes before we get the opportunity to compare our results. That’s why I’ve decided to do a few science experiments! While the home isn’t the ideal laboratory, and the small quantities I’ll be using will leave more room for error, I will try to be very clear about my methodology so that we can fairly evaluate the results. To the lab!

Whole Wheat Percentages

Proposal

To bake several breads with varying ratios of whole wheat flour/white bread flour to determine effects on dough, baking, flavor, texture, volume, and overall appeal.

I think this first experiment will be of the most interest to readers and to me as well. I frequently get questions about making 100% whole wheat breads. My bread book doesn’t have a single recipe that is 100% whole wheat (it does have a couple 100% whole rye but that’s a different story), and there must be a reason why. I think we all have a general idea what the “why” is, but I want some quantifiable results!

Hypothesis

I believe the doughs with 50% or more whole wheat flour will strike the finest balance of the variables under study.

grain.jpgThat shouldn’t be too revolutionary, but let me explain a few things. I should start by saying I love the flavor of wheat (much more than rye). It’s got a great nutty, sweet, aromatic flavor, and a beautiful appearance. But what’s the difference between whole wheat and white flour? White flour is milled from just the endosperm of the wheat grain. This is where all the starch is, as well as our favorite proteins gliadin and glutenin which combine to form gluten. Whole grain flour is milled from the entire grain, and in addition to the starchy goodness from the endosperm, it also contains the germ and the bran. The germ is where the fat and some vitamins are, and is where a new plant would grow from if you put some wheat grains in the ground. The bran is the protective outer coating, and its main benefit to us is the fiber and other vitamins.

How does the addition of bran and germ affect the flour? Well let’s look at this from a logical standpoint. If I have 100g of white flour, and 100g of whole flour, it stands to reason that the whole flour contains LESS of the starchy endosperm than the white flour. This is because part of the 100g is made up of the weight of the bran and germ. There are a few consequences of this:

1) Because there’s less endosperm, there will be less gluten available. I logically hypothesize that this will lead to greater difficulty in trapping gas during fermentation, leading to a tougher bread with a tighter crumb structure.

2) The bran and germ are hard, jagged particles that are insoluble in water. I hypothesize that this will also cause an increase in toughness and comparatively less gluten development because these particles will rip holes in the gluten, further reducing the dough’s ability to trap gas.

3) The germ and especially the bran are very absorptive. I hypothesize that this will also increase toughness and reduce volume because the starch will be robbed of some of the moisture in the dough.

None of these hypotheses should be that surprising to anyone. Obviously the real question is: to what degree will all these factors affect the end result? This imparts a subjective evaluation to the experiment, which doesn’t bother me. After all, when we talk about flavor, personal opinion reigns. Considering my ultimate goal with most breads I bake is to make a good sandwich, I think I’ll be okay with sacrificing a slight bit of nutrition and whole wheat flavor for greater volume. Nevertheless, I will keep the objective and subjective evaluation separate so you can make your own conclusions.

Methodology

Here’s the initial setup:

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I decided to make five breads of varying percentages of whole wheat. In the picture you’ll notice I used a piece of notebook paper to write out my calculations, but for the sake of easy reading on the blog I created this spreadsheet:

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The most important thing I’ve learned from reading Bread is to compute doughs in terms of bakers’ percentages. Simply put, everything in the dough is measured (by weight) as a percentage of the amount of flour in the dough (by weight). To make this easy, I used 100g of flour in each of the five doughs. You’ll notice that each dough has 68g of water, or 68% hydration. This is a common amount of hydration for breads. Also common is 1.8% salt and 1.2% yeast. Totaling it all up, we get five doughs each weighing 171g, which comes right out to 6oz, or the size of two dinner rolls.

I felt that using the same ratios of ingredients would be the fairest way to compare results, but it does present us with one main problem: As mentioned above, the bran steals moisture from the starch in the dough. This means that, although each bread is technically 68% hydrated, the doughs with more whole wheat will seem less hydrated.

When I bake regularly, most of my breads have at least 10% whole flour in them, and often up to 50%. With these breads, 68% hydration is normal and expected. When I put absorptive ingredients in bread (such as whole flours of course, but also included are things like ground flax, oats, seeds, etc), I consciously make the decision to add more water, but how much more I add is usually an arbitrarily chosen number (percentage, actually). For example, Kath’s Breakfast Bread is technically a 91% hydrated bread!! But in actuality, I included the oats and ground flax as absorptive ingredients, and using their weight yields a hydration of 70%.

So in this experiment, I had to make a decision: I could use the same ratios in each dough, which would allow for better comparison of the effects of whole wheat on water absorption but at the expense of quality in the higher percentage whole grain breads…. OR I could have upped the water amount in the higher percentage breads in order to make them more like a bread I would be likely to bake at the expense and difficulty of including an extra variable. I opted for the first choice, mostly because I want to know just how much of an effect the whole grain has on water absorption.

You may be thinking, “this seems unfairly biased towards the lower percentage breads” but you have to remember that for the 0% bread, a hydration of 68% would be considered high, and approaching the level of ciabatta. As a consequence, it will be stickier and present difficulties in shaping. I think ultimately you’ll appreciate the way I conducted the experiment because it will help you in deciding how much whole wheat flour you want to put in your breads. The water will be an after thought.

Because I’m dealing with such small amounts of flour, it would not have been possible or practical to use a mixer to knead the five doughs. What I opted to do was mix all the bread flour into one dough and all the whole wheat into another and them combine them. To do this I put all the white flour plus 1/2 the water, salt, and yeast in the mixer and mixed for 4 minutes until gluten was decently developed. Here’s the white dough mixing:

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Notice how sticky it appears and the streaks it left on the side. This is about halfway through mixing, and it eventually came together in a soft ball, but there were still a few tiny streaks of dough around the edges. I then repeated this with the whole wheat flour:

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Notice here that the dough seems much drier and cohesive – a result of the bran absorbing the liquid. After these two dough balls had been mixed, I used the food scale to measure dough balls of 171g, making sure to adhere to the proper percentages. Here’s the 50% dough, which required 85.5g of each dough:

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Here are the five doughs after portioning but before finishing kneading. You’ll notice there is some flour on the surface to prevent sticking. This is from the container seen here. The flour is 50% whole wheat. This is another obstacle in the process because it’s necessary that you have some extra flour to keep the dough from sticking and tearing, but obviously this slightly skews the percentages. Ultimately, I feel very little of this flour mixture went into the five doughs, and combine this with the fact that it’s a balanced 50% and its effect should be similar across all five breads, so I ended up ignoring this factor:

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After deciding to keep the ratios the same across the doughs, I made the decision to NOT treat them exactly the same – instead I would try to make the best bread possible with each one. What I mean is I kneaded the higher percentage doughs longer to make sure the gluten was better developed. As expected, the high percentages were harder to knead and less sticky, while the lower percentages came together very quickly and easily. After kneading, I formed into tight balls, sprinkled with a tiny bit of flour mix, and covered with plastic wrap for one hour:

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Back row L-R: 100%, 75%, 50% – Front row L-R: 25%, 0%

After one hour fermentation:

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Notice how, as whole wheat content increased, the amount of rise decreased. Interestingly, when I folded the breads at this point, they all seemed to release a similar amount of gas. This implies to me that the yeast is still able to produce gas like normal, but it has difficulty expanding the higher percentage doughs. The next step was to fold them using the traditional tri-fold:

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After folding they fermented for one more hour:

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Notice that the higher percentages are still rising less than the lower, but as time goes on they relax a little more and are starting to get some noticeable volume. After this second rise, I formed the dough into tight balls in preparation for shaping:

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After a 20 minute rest (bench proof) to allow the dough to relax after the tough tightening, I gently flattened them and rolled them into small tubes. I had to very slightly dampen the two darkest doughs to make sure they would stick together when formed into tubes. Then I took a rolling pin and very gently flattened them some more so they would be suitable for sandwiches:

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These I covered with plastic wrap and let proof for 30 minutes. Then I slashed the loaves to allow for expansion, splashed some water in the 450* oven for steam, and put them in the oven. Here they are before going in:

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And after 17 minutes of baking!

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I was surprised by how similar the crusts looked. The crumb is a different story, however:

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Results

I cut a small piece of each bread and weighed them out. To give you an idea of the volume, here they are all together. Each one of these is about 31g give or take 2g, with the 0% on the left and 100% on the right:

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I tasted each one individually without any spreads or dipping, and between tastes I cleared my mouth with tap water. They were still warm but not hot. Here are some closeups of each bread along with a breakdown of their flavor:

The 0% bread was very light in flavor and texture. It had an aroma of warm milk or yogurt with a faint buttery taste. The texture was springy and chewy:

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The 25% bread tasted like faint wheat and butter. It still had a nice fluff and chew:

 

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The 50% bread had an aroma of lightly toasted nuts and a hearty wheat flavor. It was denser than the previous breads but also had a light quality to it:

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The 75% bread had a strong wheaty flavor approaching the roasted scent of raw flour. Considering the gradual increase of the preceding breads, it was a surprise how much this bread was denser even than expected:

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The 100% bread had a strong toasty and roasted aroma, with earthy flavors of dirt and raw flour. It was incredibly dense with very little spring. The crumb didn’t fleck away in strands so much as crumble apart:

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Conclusions

My favorite bread was the 50% whole wheat. It truly was the perfect balance between volume and flavor. The lower spectrum was too light and didn’t have enough flavor. The upper was too concentrated. I think the use of sourdough would correct these problems. It would add an extra dimension to the lightness of the lower percentages and would mellow the flavor of the upper ones.

When I speak of the density of the crumb, I’m not so much talking about how tough the breads are, so much as how tightly packed they are. The 100% was no more difficult to chew than the 0%, but personally I find the fluffier breads more pleasurable to chew because of the spring factor.

What can we draw from this to make us better bakers? First off, it’s clear that as the amount of whole grains increase, an addition of water would be helpful. I don’t think this would have made the difference between a super fluffy 100% bread and what I made today, however. I think this merely would have allowed the starch to connect better. As I mentioned above, the 100% didn’t pull apart in beautiful strands like you see bread do in commercials. Looking at the picture, it looks more like arranaged “granules” of starch. If water had been increased, I think these granules would have linked up to form strands.

Also, I want to be clear that while the 100% had a strong flavor of grain and flour, it was not unpleasant by any means. It just didn’t stand as well on its own. It would make an excellent bread for dipping in soup. While I think many people would prefer the super light flavor and texture of the 0%, it didn’t do much for me. White sourdough would be nice, but this was just too bland. It might make a nice sandwich if you have some light ingredients, but I think a small amount of whole grain flour outweighs the flavor at very little expense of volume.

In conclusion, it appears that once the percentage of whole grain flour exceeds 50%, its effects become dramatic on the final product. Because the ultimate sandwich is my goal, I’ll stick to no more than 50% whole wheat breads.  Happy baking!