Why won't my vegies cook and pork belly crackle?

• Neil Perry's roast pork belly with braised greens

I have a beautiful big new roasting pan but my vegies don't cook and my pork belly won't crackle. G. Lynn

Unless your kitchen is home to the tonne of steel that is an Aga, your oven is simply a box of hot air. Those old-fashioned ovens such as Agas and wood-fired Metters use combustion to heat great chunks of steel. The heat radiates out from the steel and cooks the food. In a modern oven, gas flame or an electric element heats air and this then cooks the food. Air circulation is very important for evenly cooked food. High-sided pans can restrict airflow. They are great for big items such as slow-cooked legs of lamb or a Christmas turkey, when you want to take things slowly. But when you need a good burst of heat, such as crisping pork belly, the high sides slow things down. I always use a baking tray with sides low enough to get adequate airflow. If your oven is fan-forced, make sure the fan is on.

My grandmother told me to always spoon soup away from me, not towards. Why? P. Lincoln

Take a soup spoon. Dip into a bowl of soup. Bring it straight towards your lips. There's a good chance you'll drip some on the table or your shirt. If you'd had a big night on the McWilliam's Cream Sherry the night before your hand might be a little less steady and the risk of dribbles will be greater. (My grandmother was a Methodist and only drank fortified wine for medicinal purposes.) Spoon the soup away from you and lift it up and back towards you and any drips will end up in the soup bowl and not in your lap.

​Why do recipes ask to cream the butter and sugar until "pale and fluffy"? R. Wong

It's all about making your cake light. Butter is roughly 15 per cent water. Add sugar and beat. The water dissolves the sugar, and the mixture traps tiny air bubbles. After you've added the eggs, folded the flour through, poured the batter into the cake tin and then placed the tin in the oven, these air bubbles expand as the batter gets hot. This matrix of expanding bubbles, along with gas from raising agents, gives the cake its spongy character. Before the development of chemical raising agents in the late 1800s, the creaming of sugar into butter was the only method of making cakes light without using yeast.

My oven clock is always running slow. L. Jenkins

The power coming into your home is 240 volts AC. AC stands for alternating current. This means the current alternates its direction at regular intervals. In Australia, the electrical current runs at 50 Hertz or 50 times a second. That frequency, however, can fluctuate between 49.85 Hz and 50.15 Hz. If the electricity supplied to your home is running at 49.85 Hz your oven clock, over time, will run slow. Mine was set sometime before the last blackout and has been flashing '12:00' for the past 18 months.

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