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Hydration matters. Not just to athletes and long distance runners. It matters to bakers. How much water is in your dough is crucial to how the crumb develops. It’s amazing how a few grams more or less of water can make a real difference in the resulting loaf of bread.
This week I did a little experiment that got me thinking about hydration. I made a loaf of bread in the machine using the “French” recipe and settings, (see my previous post about making French bread in the machine) but this time substituting the same volume of K2 organic bread flour for the called-for white bread flour. The result was a dense, misshapen loaf – tasty but not anywhere near the result I had expected. Very crisp crust. And I think hydration was the reason.
Or, more accurately, the lack of sufficient hydration for that kind of flour. But because the recipe is in volumetric measurements, not weight, the calculation of actual hydration is at best inexact. In future, I will have to measure then weigh the ingredients before mixing, to better understand the hydration percentage.
K2, by the way, is a small flour mill in Beeton Susan and I visited late last year. Great artisan products, and a bread market on Sundays. Worth taking a trip. I came home with 10lbs each bread flour and Red Fife flour.
Red Fife is a Canadian heritage grain, a whole wheat flour I have only used minimally, but plan to experiment more with in the coming weeks. I do not know the exact protein percentage of either (although this NatPost article suggests Red Fife has lower protein, this report on a lab analysis suggests that’s not true: but that “the gliadin protein level is ~35% of this wheat’s overall gluten protein content. Wheat gluten’s insoluble proteins are gliadin and glutenin. This compares to ~80% gliadin protein levels found in a popular modern bread wheat.” And the nutritional label (see image on left) on this site suggests it’s actually higher protein that commercial AP or bread flours – 15%! Food With Legs site has a label that shows 13%. Harvest Hastings shows it at 13.4%, however… and if you wonder what the falling number of 340 cited is, see here and here*).
In my few tests, whole wheat flours and artisan blends tend to have different weights than the usual commercial bread or unbleached white flour I use. Plus the weight per cup changes depending on whether the flour is sifted or fluffed (or compacted).
My own per-cup weights are sometimes as much as 20% more than those shown in books and on sites for the weight of a cup of flour (typically 125-140 grams unsifted for AP flour, but I’ve weighed it over 160g). That would throw off the recipe’s hydration which is based on commercial all-purpose or bread flour (and a good reason to have recipes listed by weight, not volume).
By the way, Lime Leaves and Taste Buds says this about Canadian whole wheat flour, just adding to the reasons to buy artisan flours rather than commercial blends:
Even more disheartening is that fact that whole wheat flour sold in Canada is not necessarily whole grain due to a ridiculously outdated piece of 1964 regulation which allows millers to legally use “whole wheat” on the label despite their removal of up to 70 per cent of the wheat’s germ!!!
As a sidebar note, the K2 bread flour has a wonderful texture, a bit like having cornmeal added to the bread. That may lessen somewhat if there is higher hydration and longer fermentation time to soften it. However, I really liked the texture and flavour. But back to hydration…
Look at a bagel: dense, chewy. It’s made with low hydration, probably the lowest of all bread types: usually around 50-55%. That’s the percentage of water to flour, by weight (see my earlier post on bakers’ percentages). French bread is usually around 60%. Ciabatta – a nicely aerated bread if well done – is about 65%. Some artisan breads are even higher – 70% or more. They could be in the high 70s or even 80% range.
After that, dough gets very sticky and is harder to work with. Really wet doughs don’t hold their shape as well during rising and baking. As sourflour.org notes:
On the higher end of the spectrum you have breads like focaccia and ciabatta, which could be 75-85% hydrated. These doughs are extremely sticky, and need different types of handling. Because they stick everywhere, kneading does not usually work on these doughs, and instead you can use techniques such as stretch and folding, french folding, or just letting the dough develop the gluten over a long period of time on its own. These doughs can be roughly shaped, but because they are so wet, need careful handling. Because they are so hydrated, they might need a bit more bake time than usual prevent the inside from being gummy.
The K2 bread flour is more like a whole wheat flour: it has more of the husk and bran than commercial white flour. That extra material absorbs water, removing it from the flour. One of the reasons whole wheat flour doesn’t rise as well as white flour is that higher absorption.
Water helps the yeast spread and is necessary for them to feed – which in turn creates the gas that lets bread rise. Too little hydration creates dense, short loaves – squirrel food we call them here (those that are even too inedible even for my taste…).
Too much hydration and gravity overcomes the gluten’s bonding ability and bread can’t keep a good shape. Bakers call wetter doughs “slack” doughs. Chili and Chocolate offers this table of dough types (whether these are actual bakers’ terms, I don’t know):
- Stiff & Dry- 58 to 60% water content
- Firm & Tight – 60 to 62%
- Modestly Firm – 62 to 63%
- Malleable – 63 to 64%
- Soft – 64 to 65%
- Slack – 65 to 67%
Oil and other fats like butter don’t count when calculating hydration levels, although eggs do (no one I’ve read seems to count honey, molasses or agave syrup in the calculation, either).
There are sites that give you tips on handling high-hydration doughs, like this one at Weekend Bakery.
Working with high hydration doughs can be difficult. When working with very soft and wet dough, for instance baguettes, ciabatta or breads like our Baguette Boules it will take a while for you to come to terms with the stickiness of it. You will ask yourself: “Should it be this sticky?” and maybe end up with more dough on your hands than your work surface! Do not panic, it’s all part of the wonderful journey that eventually leads to the land of creamy crumb and crusty loaves!
To see how critical this is to the baking process, here’s a paragraph from sourflour.org about calculating hydration:
Once you know the hydration level of your starter, you can calculate the hydration level for the dough you are making. If you are using 300g 100% hydrated starter, 300g flour, and 200g water, your total flour weight would be 450g and your total water weight would be 350g. Therefore your dough would have a hydration level of 350/450 or 78%. If you had instead used 300g 60% hydrated starter (187.5g flour, 112.5g water), you would end up with 64% hydrated dough (312.5g water/487.5g flour). If you are adding other types of ingredients, remember to calculate how much water is coming from them; eggs are about 75% water, while milk is around 82%.
This matters because I’m going to start a new bread using a starter this week. I’ve been somewhat cavalier about my levain – I feed it according to sight and feel, rather than measuring exact amounts to maintain a constant viscosity. It’s somewhere between 85 and 125% hydration at any time.
In his textbook on breadmaking techniques, Jeffrey Hammelman gives these percentages for typical breads:
- Baguettes with poolish, 66% hydration, all bread flour
- Ciabatta, 73% hydration, all bread flour
- Pain Rustique (rustic bread), 69% hydration, all bread flour
- Country Bread, 68% hydration, all bread flour
- Roasted Potato bread, 61% hydration, 85% bread flour / 15% whole wheat flour / 25% roasted potatoes
- Whole wheat bread, 68% hydration, 50/50 whole wheat and bread flour
- Semolina (Durum) bread, 62% hydration, 50/50 durum and bread flours
But of course, your mileage may vary, as they say. Your local environment – including humidity, temperature and altitude – can affect the rise. Clearly the flour does, too.
In my limited experience, all whole wheat flours, multi-grain flours, or organic (coarse) flours seem to absorb more water, thus need additional water to rise more. I’ve also read (but not verified), that the bran and husk fibre remaining in whole wheat and similar flours can act like microscopic knives, cutting gluten strands. Not sure if this is true, or how to overcome it (aside from lowering the percentage of whole wheat flours in a mix).
And, of course, few people actually agree on what “good” or preferable hydration is for any particular type or loaf, although the ranges are generally similar for types of bread. basically: higher hydration = bigger air holes.
Baking911 says the typical hydration for popular bread types like “white sandwich bread, French bread, and challah” is between 57 and 65% hydration. Most of my recent breads have been around 65-70%, although I’m not sure what the bread machines loaves come in at (I suspect 60-65%).
Chile and Chocolate says “American style breads usually are about 60 to 62% hydration, French style breads between 62 to 65%, and Italian style (ciabatta) breads upwards of a 68% range.”
Artisan Bakers has some photos showing the results of different levels of hydration, noting
Although differences in shaping and baking techniques account for the differences in appearance and crust , the basic ingredients of flour , water, salt, and yeast are always the same, so it is the hydration that gives the dough its defining quality. A dough with a 70% hydration that was shaped and baked like a bagel would never be a bagel.
Sourdoughhome.com also has some good photos comparing flour mixes and hydration levels, noting that flours are not all the same:
The issue here is that there isn’t a single substance we can identify as “flour”. Or even ” bread flour”. I have long felt that the results of mixing a known quantity of flour and water may not result in a very similar dough because of variations in flour.
Samartha.net has some similar experiments with hydration levels in a bread using a starter, and very detailled explanation of the dough mixes. It concludes:
The bread turned out to be fairly sour and the higher hydration breads had a more transparent and chewyer crumb. Also interesting was the much shorter baking time (25 minutes) of 60% hydration compared to the higher hydrations (40, 45 minutes). The 75% hydration dough was sticking everywhere, unslashable, and could only be managed with oiled plastic foil and large amounts of corn meal – definitely not recommendable.
Perhaps the best advice comes from a post in Azelia’s Kitchen: “Obsession with Hydration is Pointless.” She writes:
I see photos of bakers showing their very open very holey crumb which are met with lots of “oohhhs” and “aahhhs” of astonished admirers and the conversation will involved discussing method as well as hydration percentages, and the oohhs and aahhs starts happening usually around 75% maybe even 80% hydration. This is only half the story the other half missing is the flour.
Along with how much water you have equally important but rarely discussed is the flour, the protein percentage of the flour. High protein flours can absorb as much as 30% more water than lower protein flours, something noted in Harold McGee and baking textbooks. I’ll mention below how not all protein in flour is equal but as a general rule an 11% protein flour which is typical of the French T55 flour will tolerate less water without the dough losing its shape than a strong Canadian style flour of 14-15% protein.
But the tinkerer inside me can’t quite stop obsessing…
* From Northern Crops.com:
Falling number is a test more recently introduced into country elevators. It gives an indication of the amount of sprout damage that has occurred within a wheat sample. Generally, a falling number value of 350 seconds or longer indicates low enzyme activity and very sound wheat. As the amount of enzyme activity increases, the falling number decreases. Values below 200 seconds indicate high levels of enzyme activity.
Why is this important? Sprouting can affect food made from wheat in many ways. It can reduce mixing strength, cause sticky dough, and affect loaf volume and shelf life. In pasta, sprouting can reduce shelf life, increase cooking loss, and produce softer cooked pasta…
Falling number tests can be run in remote locations like elevators or testing facilities and replicated anywhere in the world. This is important to importers who need to verify the quality of their purchases. Many buyers from export markets have written minimum tolerances of 300 to 350 seconds into their purchase contracts. In the past several years, grain buyers have discounted wheat for falling number values below 300 seconds.
This site says: “In general, values below 300 seconds are indicative of poor quality for milling and baking purposes”
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