Topics In This Section
1. Introduction
2. General Rules of Frying
3. Temperature Control
4. Preparation of Food
5. Fat Absorption and Topping Up
6. Choice of Frying Medium
7. The Spoilage of Fats and Oils
8. Cleaning
9. Frying Specific Foods
10. Recommended Frying Temperatures
11. The Basic Chemistry of Fats and Oils
12. The Chemistry of Fat Spoilage
13. The Visible Effects of Chemical Spoilage
14. The Role of the Oil Refiner
15. The Role of the Fryer
16. Fire Hazards
Reproduced with permission from Pura Food Products Limited
5. Fat Absorption and Topping up
Most operators top up the fryer from time to time. As a general guide the fat absorption of potato chips is usually 5-6%. That is, 10 kg of potato chips
will pick up about 500-600g of fat during frying. More porous foods such as doughnuts will absorb more fat than this and figures of up to 30% have been recorded,
Fat absorption depends upon the time of frying (the longer the frying period, the greater the absorption), the total surface area of the food (the greater
the area, the more absorption), the type of food surface (rough or porous surfaces absorb more fat), the frying temperature (the lower the temperature, the greater the absorption),
the nature of the food and the nature and condition of the fat.
The general procedure in frying is to top up the fat as required. To some extent, the natural spoilage of the fat by heat is controlled or damped down by
this process of continually adding fresh fat to the fryer. It is important to use the optimum amount of fat for the weight of the food being fried as this results in the best rate
of topping up. For this reason, it is wise to reduce the number of fryers in use when trade is less brisk.
It has been said that if at least 20% of the fat is replaced daily, the frying medium is much less likely to require changing.
Nowadays with the use of blanched chips being more popular, top up rates are lowered and frying life extended due to the incorporation of blanching oil into
the frying medium.