September 16, 2012 - 3:07pm
Mottled Appearance
Below are pictures of the upper crust and bottom crust of a rustic bread I've been making recently. These pictures illustrate a problem I've been fighting for some time with many of my breads. I can't figure out why the upper crust has a mottled appearance versus being nicely browned. The bottom crust which was on parchment paper against the baking stone shows no such issue.
After shaping, the recipe calls for placing on parchment paper and covering with plastic wrap. I almost always spray lightly with oil to keep the plastic wrap from sticking otherwise I have a really hard time getting it off for baking without messing up the appearance of the loaf. Could this be the issue?
Any pointers and help will be appreciated.
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I have seen that same mottled appearance when I (formerly) used to use a water sprayer to create steam during the bake. If water got onto the loaf in the first few minutes of baking, the crust would have that appearance. But undoubtedly that is not the only cause. It could be something to gluten development and shaping. If you post your recipe and your procedure, and the type of oven you are using, it may help to identify the problem.
-Brad
... you can lightly flour the dough surface to stop it sticking to the plastic wrap. I do. After the dough is finally proved and ready to bake, simply brush off the excess flour with a dry brush - or leave it on, if you prefer.
My guess is the oil is your problem - but can't be 100% sure from those photos. Trial and error - leave off the oil, try the flour trick and report back pretty please!
All at Sea
might be something mixed with the oil. Are you using an oil pump type sprayer or one under pressure? What kind of oil and what is the propellant? Maybe there are some clues there. List all the ingredients for some of our knowledgeables. I suspect water in an oil suspension might be the cause. (hydrogenated oil?)
I dribble a little olive oil on my plastic and rub it around with my hands for a thin coat or I pat my dough with oiled hands. My hands are thankful. I don't get this reaction. (((knock on wood)))
or garden leaves and spray the loaf... might get some interesting effects. Do let us know what happens. :)
...or spray some leaves, ivy comes to mind, and stick them onto the loaf (remove for baking) that might also be interesting. Always looking for interesting ideas...
I doubt that publishing the whole recipe and technique right now will be of much benefit as this phenomenon is happening with multiple recipes. Instead, I'm going to try some of the suggestions given - oiling the plastic wrap with olive oil and using flour and see what happens. I will report back.
Just for grins, I took out the spray oil and looked at the ingredients. It includes soybean oil, soy lecithin, dimethyl silicone, and propellant.
I baked again yesterday - finally! Same recipe only this time I didn't spray oil on the top of the dough. Instead I lightly dusted the top of the loaf with flour before covering with the plastic wrap and allowing to proof. I was able to get the plastic off with no issues; however the appearance of the baked loaf is the same as before only now with wisps of flour on top. Still has the hazy appearance shown above.
The recipe calls for doing the initial fermenting in a lightly oiled container - same as most of my recipes. Now wondering if that could be contributing to the issue?
Detective work... Q's
What kind of bowl (material) are you using? Old or new?
When you shape the dough, are you keeping the top of the dough, on top? Flipping the dough out of the bowl usually turns it upside down. If this bowl surface is becoming the top surface, try to alter the shaping so that the top skin is stretched and tucked under for shaping.
Try covering the final rise with just an upturned bowl.
Use water instead of oil.
In the oven... fan? steam? what's the set up and source of heat?
Excellent questions that are provoking some thought on my part.
As to the type of vessel used for fermenting, for larger batches it's an old plastic bowl, for smaller ones I'm using a new plastic container. I will try a glass bowl next time and see if that has an effect.
Good points on shaping. I may well be getting the bottom on the outside by not paying attention. Never considered the need before - I thought that the shaping stretched the outside taut enough. Will definitely pay more attention!
Oven setup is very conventional. I have a fibrament stone that I pre-heat for about an hour. For steam I use an old aluminum pan that I put in during the pre-heat and then I add hot water just before baking. Also do two or three sprays of the sides of the oven with a plant mister about 30 seconds apart.
Thanks. I will try some of your excellent suggestions and let you know what happens.
The mottling, or haziness (as I think of it), is directly related to the oil on the plastic wrap. I have been able to see points on the crust where the wrap was in direct contact with the dough and areas where the wrap was riding just slightly above the crust without touching. Contact = haziness, non-contact = normal crust coloring.
As to the chemistry involved, I haven't a clue. It doesn't seem to matter whether the oil came from an aerosol can, a manual pump, or even oil lightly spread by hand on the plastic. If I were baking for a competition, I would defiinitely avoid the oil. Since I'm not, I tolerate the slight imperfection and focus on the taste, which doesn't seem to be the least bit bothered.
Paul