What are the 3 factors which cause food to spoil?
- Chemical
- Physical
- Microbiological
What temperature should a fridge be kept at?
0-4C
What temperature should a freezer be kept at?
-18C
Why is a fridge not meant for long-term storage of vulnerable or perishable items?
The refrigerator only slows activity of enzymes and microbes, so it’s not meant for long-term storage
What are 6 materials which should be refrigerated?
- Dairy products
- Meats, vegetables, fruits
- Creams and icings
- Nuts and nut products
- Pastry in bulk or made-up units
- Most decorated products
Why do doughs need to be wrapped before refrigerating?
To prevent skinning. Fans in the cooler circulate air and this causes moisture loss from the surface of items.
What are 4 materials which do not need refrigeration?
- Non-perishable items, which are low in moisture and stored in dry storage
- High-sugar items (ex. dried fruit or glaze fruit)
- Jam and proprietary pie fillings
- Food that is 100% fat is most often stable because there is no moisture present to encourage the growth of microbes, although these products may go rancid if the storage temperature is high.
What are the controls set for a retarder?
1-2C, 85% RH
What is the difference between a retarder and a refrigerator?
A retarder is used for the holding and thawing of yeast goods.
A refrigerator is used for the storage of various items, and also used as a cooling unit.
(ex. a retarder is not used to cool sauces or puddings etc)
How does a retarder/proofer operate?
Place the frozen product into the retarder. Once thawed, the retarder will hold and then automatically proof the goods in time for the morning bake.
What happens to the water in a product that is frozen?
When water freezes, it expands.
When water freezes slowly, the ice crystals become large and irregular. These large ice crystals may rupture and destroy the cells of the product, resulting in a loss of color and flavour
What are 4 reasons to freeze products Quickly?
- To reduce the period of time that the product is subjected to temperatures which accelerate staling
- To reduce the chance of separation of ingredients (due to the varying temperatures at which they freeze)
- To stop fermentation
- To eliminate large ice crystals
What is the best way to wrap a dough unit before freezing, and why?
Wrap the dough in paper, then in moisture-proof wrap. If moisture-proof wrap is used for wrapping, it causes the dough to sweat due to the rise in relative humidity inside the wrap as the temperature drops. This creates condensation with a subsequent wet, sticky dough surface.
What is freezer burn?
Freezer burn is physical damage due to the evaporation of moisture from the surface of the product. The outside of the item is dry and forms a layer that separates. Freezer burn can be prevented by good packaging of the product.
What are 4 types of freezers?
- Walk in freezer
- Reach in freezer
- Blast freezer
- Nitrogen freezer
What are the temperatures of the 4 types of freezers?
- Walk in freezer -18C
- Reach in freezer -18C
- Blast freezer -34C
- Nitrogen freezer -184C
What are 6 reasons that freezers are beneficial to bakers?
Freezers:
- Eliminate a portion of night baking
- Help to eliminate production peaks (controlled production)
- Cut down stales through improved stock control (you only bake what is needed when it’s needed)
- Allow for some products that are easier to handle frozen (ex. high ratio cake)
- Provide a more economical use of staff (production on slow days)
- Enable the baker to produce a wider range of products
What are 7 items that should not be frozen?
- Creams
- Custards
- Jellies
- Fondant-coated products
- Fudge-coated products
- Chocolate-coated products
- Almond paste products
Describe the preparation of frozen yeast items prior to baking
Remove yeast product from the freezer.
Allow the thaw completely.
Proof.
Bake.
What happens to buns that are not thawed all the way before proofing?
If bus are not thawed all the way through before proofing, they tend to have a large collapsed air pocket in the centre. This is because there is uneven gas expansion, and the outside cells have expanded but the interior is still frozen. The interior remains a solid core that collapses when heat is applied.
Which sort of cake batter freezes best?
A richer cake batter
What are 5 means of food contamination?
- Bacteria (dairy products)
- Protein foods (meat)
- Mould (starchy foods and fermented foods)
- Yeast (sugary foods and fruit)
- Infestation (insect eggs in ingredients)
What are 2 means of Chemical food contamination?
- Rancidity (high fat ex. butter and nuts)
2. Enzymes (fruit, vegetables, dough)
What are 2 means of physical decay in food?
- Staling (fermented products)
2. Drying (general foodstuffs)
