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< prev - next > Food processing KnO 100644_Baking (Printable PDF)
Baking
Practical Action
Bread rolls
Small cakes
Madeira, fairy cakes
Shortbread (small)
Puff pastry (sugar glazed or filled)
Sausage rolls
Sponge cakes (small)
Buns (medium rich)
Meat pies, patties (small)
Shortcrust pastry (e.g. pastries, tarts,
custard pies)
Sandwich sponge cakes
Rich biscuits
Light gateaux
Shortbread (large)
Rich sweet pastry
Malt and fruit breads
Fruit cake
Macaroons
Birthday cakes
Rich cakes
Gingerbread
Meringues
1 Baking time depends on the size of the pieces.
230
221-232
221
221
215-227
210-220
215
204-215
204
204
204
193-204
193-204
163-204
177-188
171-182
166
160
160
121
10-12
10-12
10-12
10-12
12-15
12-15
15-20
15-18
20
18-20
12-15
15-18
15-18
10-15
60-70
10-12
20-30
2-3 hours
15-20
10-15
Table 2. Baking temperatures and times for different products (From Fellows and Axtell, 2004)
Foods such as breads that require a surface crust and a moist interior need a high oven temperature,
whereas products such as biscuits that have a low moisture content throughout are baked at a lower
temperature to enable moisture to evaporate from the food without forming a surface crust.
The design and construction of directly heated fuel-fired ovens should enable the oven to bake
quickly, but also retain sufficient heat to give several hours of baking. The crown contains stationary,
very hot air that acts as a reservoir of heat, which is radiated down to bake the products. The more
heat that is retained in the crown, the longer the oven can be used before it is necessary to re-fire it.
However, the amount of radiated heat that reaches the product is related to the square of the
distance between the product and the crown. There is therefore a compromise in oven design
between having a large amount of heat retained by a high crown and a smaller amount of radiated
heat that reaches the products. The oven design should also have a high capacity, low fuel
requirement and relatively low costs for construction or repairs. The main disadvantage of direct fuel-
fired ovens is the risk of contaminating products with smoke and ash.
Indirect ovens have continuous operation because the fire can be maintained without interrupting
production. The simplest designs have a separate firebox with brick or tile-lined flues surrounding
the baking chamber. The flues must have an access hatch to remove soot and the flue lining material
must be able to withstand the intense heat without cracking, which would cause it to collapse.
Alternatively, radiator tubes may be used to duct the hot air through the baking chamber, or fuel is
burned between double walls. A ‘double-drum’ oven may be constructed using a 200-litre oil drum
that has one end removed and a flue fitted to the other end. The horizontal drum is covered with soil
to insulate it, with the flue rising vertically through the soil. A second smaller drum is the baking
chamber, located on bricks inside the larger drum. A fire is lit between the two drums and food is
placed in the baking chamber. The end of the drum is replaced while baking takes place, removing it
as needed to rekindle the fire or empty the oven. If indirectly heated ovens are used, bakers may find
it more useful to use several smaller ovens set at different temperatures to bake different products.
The rate at which a food bakes depends on a number of factors: 1) the type of food and size of the
pieces. Smaller pieces heat faster because of the shorter distance that heat has to travel to the
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