I'm sure other and better experts will join in but here is my understanding:
- In a dough with about, let's say, 1 kg of flour. Is there a magic formula to determine how much refreshed starter / sponge to make? Can I compensate for a small sponge by bulk fermenting the bread longer ?
Most bread formula are in terms of Bakers, percentages, that is relative to total flour.
Different bakers have different formulas. The amount of levan can vary from typically 20% to over 200% (200% means half the flour is in the levan).
A typical formula for white bread might be:
Flour 20% (200g)
Water 20% (200g)
Mother starter 1% (10g)
Ferment for 8-12 hours at 30C
All the levan 40% (400g)
Flour 80% (800g)
Water 45% (450g )
Salt 2% (20g)
This formula has 65% hydration with the water in the levan. Varying the amount of water by small amounts will make big changes to the viscosity of the dough and hence its ease of handling, and to a lesser extent the hole size in the finished dough. Don't forget the dough will get much wetter as ferments and proves, as the acid attacks the starch and converts them to sugars.
Different flours adsorb differnt amounts of water. Wholemeal will adsorb more, say 55%/550g/75% hydration.
You can compensate for a smaller sponge by fermenting longer, but it will make a different bread. There are many different processes happening, and very long fermentation stages tend to weaken the gluten. Crudely, I think the sponge step develops the flavour, and dough step the texture.
- In norway the supermarket flour contains 10,7 % protein. This is gluten right ?
Is it protein content that determines the water absorbtion abilty of a flour ? Is this what is refered to as "strength" ? Or are we talking about how fine the wheat is milled ? How does this attributes affect the bread ?
I'm sure that flour will make fine bread. I think here is often too much emphasis on the exact paramters of the flour, since technique is more important. Better to choose one or two typed of flour you can easily obtain, and work with those. Oneof the problems is that millers and supermarkets do not always supply an identical product: the same flour packet may contain subtly different flour in the spring or the autumn, or on damp days and dry days.
You raise a large subject here, and if you can, go and find books on cereal chemistry. Flour is complex stuff, and there are many more parameters than just protein content, which is used as a surrogate for gluten. although it says nothing about the quality of gluten, and can be misleading for wholemeal flours since the bran contains protein. The amount of gluten is often referred to as strength, but you can (and I do) make good bread from weak flour. In France baguettes are made with weak flour. Each culture has ended to evolve local breads that make best use of the flour locally grown and available.
Other parameters people measure. Many of these interact, and none really tell you what the flour is like to bake with:
Grade of grind and particle size
Wheat variety and type (spring/winter etc)
Extraction (percentage of the whole wheat)
Hagberg Falling number (measure of amylase activity)
Gel protein test
Damaged strach granules (Farrand units)
Water adsobption (Farinograph)
In France and Germany ash content is quoted, used as an indication of mineral content.
- How much oven spring can I rely on getting from a dough? Let's say I bulk ferment my dough for 5 hours, shape the loaves (they will collapse a bit during this process), and put them straight into the oven. Will the bread rise at all ?
My loaves more than double in the oven. I get bigger final volume from less expansion in the feremention and proof stage and more oven spring.
Try and see what happens if you bake directly after shaping. You will certainly get some rise.
Retardation (putting the bread in the fridge) is another issue, The cold slows some proceses more than others. I reckon (for me) overnight int e fridge is about equivalent to two hours proof, and sometimes I shape, put the dough in the fridge, and then bake next day from cold.
- I've seen vitamin C in some recipes. What's the right way, and reason to apply witamin C in bread baking ?
Another complex subject. Vitamin C combines with the help of an oxidase enzyme present in the flour wih the oxygen in the dough to form dehydroascorbic acid, which then oxidises anothe enzyme in the flour that would otherwise attack the gluten, and also appears to assist forming the bonds inthe gluten structure.
Its more important for freshly milled flour, and for high intensity mixed doughs. If you are mixing by hand its less important - people have made fine bread for years without it. Some bread flours (King Arthur, for instance) have it already mixed in at the millers - check the fine print on the packet.
You can just add it when you make the dough. I'm experimenting with some success with mixing the dough flour, water and vitamin C together and letting them stand for about an hour beforehand.
I have some recipes on wholegrain sourdough breads, and bread with a coarser ground flour. Can I use my nice and acitve fine starter for these breads ? The recipe states to use another starter. (From rye). Is this only for taste ? Will the bread rise just as well with a fine flour starter ?
Absolutely. I only maintain one basic white starter that I use for all my breads. A baker I know just maintains a rye mother starter that he uses for all his breads, so that he can make gluten free breads without changing starter.
Hope someone can help me shed some ligh on this magic .-)
Hope this helps and welcome to a great adventure. Please don't take these remarks as gospel. They are only my current opinion, and you should not beleive everything you read on the Internet!
Edited by jackal10, 23 April 2006 - 09:38 AM.