jimtrue.com : school : CUL115 : Week 2 - Amylase, Dough Retardation & Folding

Posted by Jim True on January 23, 2010 11:12 PM. Last Updated January 23, 2010 11:12 PM

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Week 2 - Amylase, Dough Retardation & Folding

Amylase and Diastatic Malt Powder

• Amylase is an enzyme found in most cereal grains, when moistened, its job is to convert start into sugar (maltose and dextrins)
• The yeast eats the sugar and continues the fermentation process
• When the enzymatic activity is too low, fermentation is sluggish
• When the enzymatic activity is too high, fermentation is excessive
• When grains are untouched, amylase sleeps
• When grains sprout, amylase becomes active because:
1. Grains stay too long in the field before harvesting
2. Rains come during the last phase of growth
• Adding malt corrects deficiencies in amylase activity
• Diastatic malt powder is malt that has active amylase enzymes
• Diastatic malt powder is added to doughs that will endure a long fermentation time, especially if the dough is being retarded for several hours to overnight
• Non diastatic malt powder has no active amylase enzymes and is added to dough purely for flavor

Dough Retardation

• Is the process of slowing the yeast fermentation down by placing the bread dough in the cooler for a minumum of 16 hours or more. The bread may be shaped into individual loaves or one large mass. The dough should be covered.
• The benefits from retarding bread dough overnight are increased acidity in the flavor and it helps to create and extra thick crust (if dough is ahped into the final shape).

Folding the Dough

• How to Fold
• Flour work surface generously (lack of adequate flour will cause the dough to stick and rip)
• Turn dough onto work surface (the top of the dough - smooth side is facing down on the flour)
• Take one side of the dough and lift up 1/3rd of the bulk and turn it vigorously onto the body of the dough (brush all flour from dough before folding anymore dough). With spread fingers, use both hands to pat down the dough and degas it (do not expel all of the gas).
• Take 1/3rd of the dough from another side and fold it in toward the center, overlapping the first fold. Press to degas
• Take another 1/3rd of the dough and bring it to the middle of the bulk, degas
• Take the remaining dough and bring it to the middle of the bulk, degas.
• Turn the dough over so the seam side is on the bottom of the bulk
• Life the dough back into the bowl or container it was rising in
• When the dough is folded correctly
1. The dough is degased (fermentation can be impaired if the dough is not periodically degased)
2. The doughs temperature is equalized (cold room, warm dough, ex.)
3. The doughs strength is increased (a fold stretches and aligns the gluten strands)
• When to Fold
• In order to preserve the flavor of the dough, and to avoid overoxidizing mix the dough to less than full gluten development. The undermixing is corrected by folding, which in turn increases dough strength
1. Doughs that ferment for more than 1 1/2 hours = 1 fold
2. Doughs made with a high % of pre-fermented flour (55%) = 1 -2 folds
3. Doughs made with weak flour = extra folds
4. Doughs with a high hydration (ciabatta, 75-85%) = extra folds
5. Doughs with a short bulk fermentation (sour dough rye bread), do not require folding (no benefit)
6. Doughs that are by nature stiff (challah), do not require folding. They already have adequate dough strength, unless they are fermenting for longer than an hour

Steam

• Only steam bread that is not egg washed
• Steam 2-3 seconds before loading the oven and another 2-3 seconds after loading the oven (known as normal steam)
• Too much steam will deflate the dough and result in a thick, chewy crust, with the cuts that don't spring open
• Too little steam will not allow the dough to rise to its full potential
• When the dough is slightly underproofed, add a few seconds of steam to keep it moist longer, so the dough has a chance to rise
• When the dough is slightly overproofed, use less steam so the dough doesn't flatten out
• Proper amount of steam gives:
1. A rich color to the crust
2. A surface shine to the bread
3. It increases the volume of the bread
• There are enzymes in the dough that break down the starches into dextrins and other simple syrups (reducing sugars), which give the crust color
• Steaming the oven has a cooling effect on the dough, and this enables the enzymes to remain active for a longer period of time
• Without steam the dough becomes too hot for the enzymes to function and the result is a dull and pale looking bread
• When the dough shows color, pull the vent (damper) to release the moisture in the oven, and to allow the bread to dry out

The Wheat Kernel

1. Bran: the outermost layer of the wheat kernel, consisting of minerals and cellulose (fibers). The Bran Layers are made up of:
1. Pericap: the outer husk layers
2. Aleurone: the inner most layer of the pericap
2. Endosperm: The starchy portion of the cereal grain, and the protein (gluten = gliaden and glutenin) that is flour
3. Germ: Consists between 2 1/2 and 3 1/2 % of the whole kernel, it is high in fat (flours that are made from the germ go rancid quickly), minerals and vitamins

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