Why do moon cakes need to return to the oil
In Cantonese moon cakes, rolling moon cake skin with oil, transformed syrup, low gluten flour and other raw materials, after mixing to form a temporary emulsification system; moon cake skin after baking, the moisture content of the skin is very low, about 5%, but the moisture content of the filling is still relatively high, usually about 20%; so that the moon cake in the process of placing, the filling of the moisture will be Migration to the skin, dry crust in the absorption of enough water, due to water and oil insoluble, the original emulsification system will be destroyed, the oil will naturally penetrate outward, giving the impression that the cake is softer, more oily, glossy, translucent, that is, "back to oil". This is the time when the taste of the mooncake will reach its best.
What is the meaning of the moon cake back to the oil
Back to the oil refers to the moon cake placed for a period of time, the pie crust to absorb a certain amount of water, oil, and moon cake filling inside the oil after the pie crust will become soft and oily, the taste of the moon cake at this time will be the best. In cool weather, you don't need to put it in the refrigerator, you can store it at room temperature directly, if it's hot, you can put it in the fridge.
At home, the mooncakes are usually baked first and then cooled to warm when you can use a ziplock bag, and then placed in a dry place at room temperature to save it, put on 20 days no problem. The premise is to bake the moon cake must be baked through, there is also a moon cake filling in the do-it-yourself must be the moisture dry. If the moisture content is large, it will soon become moldy.
The principle of mooncake oil return
Mooncake processing added to the mooncake crust is not ordinary cane sugar, but fructose syrup. It plays a vital role in the oil return situation, molding effect, and permeability of the mooncake. Fructose syrup is a health-care starch sugar made from a mixture of fructose and glucose, which has a single-molecule structure and is therefore more favorable to human absorption. Compared with ordinary sucrose, fructose syrup has moisturizing properties, which enables the flavor and freshness of mooncakes to be better maintained. It generally takes several months to boil down high-quality fructose syrup, and processing mooncake factories must start boiling it in April or May every year. In order to ensure the quality of the crust, it would be better to use the boiling (syrup) three months in advance. In order to ensure that the sucrose is fully converted into fructose syrup, so that its composition is stable and constant will not be reverse reaction.