When to throw out potatoes

At what shade of green should I throw out my potatoes? C. Earl

You were born with an amazing organ that has been protecting you every day of your life. Your tongue is armed with taste buds that detect bitterness. They detect the bitterness in alkaloids in plants that are poisonous to us, such as the alkaloids that develop in potatoes if they are exposed to light for an extended time. In light they also produce chlorophyll, which makes them green. Potatoes can produce alkaloids if they are badly handled, and in their shoots they start their process of reproduction, which is the potato's clever way of stopping us eating its baby-making bits. So if a potato tastes very bitter, peppery or burning, don't eat it. Most of the alkaloids are found in the first five millimetres, so if you have a slightly green potato, peel off the first half a centimetre. Really green potatoes will probably be old, slightly dehydrated and worth chucking anyway. Green-potato poisoning is not common but not unheard of. Err on the side of caution and turn very green ones into Martian Mr Potato Heads.

I am religious and always say grace but feel uncomfortable about doing so before dinner at restaurants. What are your thoughts? S. Matzner

When I review for the Good Food Guide, I always mentally prepare myself by clasping my hands together and quietly bowing my head. I give myself a few moments to clear the mind of the day's trivial trials and tribulations and give the task at hand my full, unbiased attention. To an outsider it could appear that I was saying grace. Over the years I have never noticed any other diners' looks, glances or open-mouthed stares. You asked what I think? I think it's your business and no one else's. That said, the general rule of etiquette is that, while it is OK to practise religion at mealtimes, talking about it, or about sex or politics, should be avoided.

If chicken has been cooked, refrigerated, then left out at room temperature for five hours, is it safe to eat? C. Tartaglia

Put it this way: I wouldn't touch your chook with someone else's fork. Chicken, like eggs, fish, meat and milk, is considered by authorities as ''high risk'' food that is a fertile breeding ground for harmful bacteria. Your chicken has been in what health officials call the ''temperature danger zone'', five degrees to 60 degrees, for more than their recommended maximum of four hours. After this the risk of bacterial contamination rises significantly.

I love lard but a member of my family finds the smell offensive when I render it in the oven. Can I render outside? M. Wood

You can render pork-back fat in a small amount of water in a large pot over low heat on a barbecue burner or a camp stove. You know when the pot is hot enough when the water is simmering but never boiling as this would emulsify some of the fat. When it's rendered, remove the remaining solids and place the pot in a cold place. The fat will rise to the top and solidify. Make a hole. Pour off the water. Gently re-melt the fat and pour into clean, hot glass jars. I like to give jars of lard as a gift. Instead of saying it with flowers, say it with fat.

Letters

I was not aware how passionate people are about beetroot leaves. Thanks to Sue L, who wrote: ''My Italian greengrocer told me to cook beetroot leaves rather like we cook spinach. I [now] chop off and throw away stems, soak, and simmer some garlic in olive oil, add some lemon juice, then quickly stir leaves a little, then put on a lid to steam for a little longer.'' And K. Johnson, yes, it was remiss of me not to mention that when rendering back fat for lard, save the bits of crisp flesh left over as they are delicious salted and served as a snack.

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