| What is the Chorleywood 'Bread' Process (CBP) | Method in which the majority of wrapped, sliced industrial loaves are made in Britain |
| What are the three layers of wheat grain | Bran, embryo (grow into a new plant) and endosperm (white flour) |
| Define wheat flour in bread | Consists of protein (gluten) forming the support and carbohydrate (starch) which sets the loaf in the oven. Also damaged starch for water holding, enzymes for water releasing, lipids and cell wall material. Strong flour = higher protein content. Wholemeal contains endosperm, bran and germ |
| Define gluten in bread | Supplements a weak flour or supports 'bits' (e.g. seeds) in some recipes. Will enable excess expansion (for breads like Danish/slimming breads). Also, for long fermentation processes requiring extra water and work input |
| Define water in bread | Most essential and cheapest material. Optimum level is essential for; good dough development, good dividing and moulding, good texture and colour and slice strength |
| Define yeast in bread | Cells are alive until baked. Eat sugar present in flour. Give off gas which makes bubbles grow in dough. Can be killed by too much salt, sugar, vinegar, preservatives, fermented wheat flour or heat. Stored at roughly 2-5 degrees Celsius else they become active. Optimum temperature is 40 degrees Celsius |
| Define salt in bread | Sometimes added in solution as brine. Enhances the flavour, slows down yeast activity, strengthens gluten structure, increases oven spring, may slow mould growth and staling and produces a brown crust colour |
| Define soy flour in bread | Yellow powder taken from uncooked soy beans. Higher in protein than bread flour, thus improving texture. Emulsification of the dough. Increased water adsorption, improved shelf life. Provides support and structure during baking. Browner crusts and adds oxygen |
| Define improver in bread | Flour-, oil- or aqueous blend of several components with specific functional properties to modify dough characteristics and give quality attributes to bread. Contains emulsifier, oxidant and enzymes |
| What are the three examples for improver | Powder (soya flour, wheat flour, calcium carbonate), liquid-oil (expensive substrate, liquid DATEM, cant carry SSL or soya) and liquid aqueous (cheap and cant carry DATEM, SSL or soya with ascorbic acid) |
| Define emulsifier | Added as part of improver. Interacts with protein, starch and lipids. Main activities: mixing and baking |
| Define enzymes in bread | Increase speeds of actions. Amylase (starch) used for oven spring and shelf-life. Hemicellulase (cell wall material) used for volume and crumb quality. Lipase (oils) used for crumb quality and sometimes volume |
| What are the two main preserving ingredients and what is their function | Vinegar: prevents mould growth, though too much slows yeast down, thus lower volume, softens the dough and gives a strong flavour
Fermented wheat flour: natural preservative made from wheat. Increases mould-free shelf-life, provides flavour and harms yeast, thus more needs to be added |
| Define sugar in bread | Slows down yeast activity, increases dough setting temperature. Normal UK bread has no added sugar, thus sources of sugar: white/wholemeal flour, malted wheat flakes, malt flour, gluten and soya |
| What is the CBP process for bread making | Mix -> divide -> either round then first proof or by-pass -> final mould -> final proof -> bake -> de-pan -> cool -> slice/bag |
| Why was the CBP process used instead of current processes at the time | As it replaced the long bulk fermentation by short, intense mixing |
| What is the aim of mixing in bread | To get product specs by sensing product and raw material variation and then adjusting the mixing process accordingly. Four objectives: produce an even mixture, generate bubble nuclei, develop and hydrate the dough proteins and bleach the yellow pigments. Also heats up the dough. Longer mixing time = more energy transferred. |
| Define first proof | Yeast ferments the dough and produces gases, thereby leavening the dough |
| Devine final moulding | Moulding imposes the desired internal structure and the outside shape. Takes a variable input, provides a stronger crumb structure with finer, more even texture, and delivers this to the panner. Better texture as greater bubble elongation and orientation and squeezes out big bubbles. Last chance to even out product |
| Define panning | Place the dough piece (s) centrally, flat in the base of the tin, in specified orientation. Significantly influences final shape and crumb texture. Poor placement can ruin product. Either in 4-piecing or 1-piecing |
| Why is 4-piece panning better for crumbs | Gives a softer but stronger crumb |
| Define final proof | Provides and environment conductive to controlled expansion without moisture loss. Requires optimum conditions for yeast to grow whilst preventing dough from skinning. Proving = growing bubbles. 15 mins, bubbles are clear. 50 mins, gluten network has been stretched by the big bubbles. More time and it could collapse. Bubble walls split during proof, but the liquid films hold the gas |
| Define bake | Controlled heat delivery to product to achieve specs whilst controlling weight loss. Involves rapid increase in gas pressure and changes in dough rheology. Gas pressure increases due to; final evolution of carbon dioxide by yeast, effects of temperature on solubility of carbon dioxide and thermal expansion. Works from outside in. Fall in dough viscosity or consistency. Kills yeast and active ingredients, stopping gas production. Also stage which carbon dioxide escapes and pores are produced. Creates crust colour and water loss |
| Define cooling | Get product to right conditions for slicing and bagging within specs whilst controlling weight loss. Essential to minimise mould growth. Optimum spacing for optimal cooling. Temperature, time and humidity need to be controlled |
| What are some overall plant considerations | Keep well maintained, flour and improver needs to be matched, optimise recipe, mix size, set the divider/final mould/panner and regular maintenance |
