My housemate keeps leaving the Vegemite out on the kitchen bench. I say it belongs in the fridge. Who is right? L. Meagher

Neither. Your housemate is a slob. The Vegemite should be put back in the pantry where it belongs. There it will remain quite happy until its use by date. Don't waste energy keeping it cool.

A recipe calls for a cup of molasses. Can I simply weigh in 250 grams of molasses? A cup of water is 250 millilitres and weighs 250 grams. L. Moore

A standard Australian cup holds 250 millilitres of liquid. One millilitre of water weighs one gram. So 250 millilitres weighs 250 grams. Molasses, however, has heaps of sugar dissolved in it – just under 100 grams per cup. Add up all the sugar, minerals and so on and a 250 millilitre cup of molasses weighs around 350 grams, about the same as a cup of honey or golden syrup (a cup of maple syrup weighs about 322 grams). Weighing sticky syrups directly into a bowl that has been set on zeroed scales will avoid the mess and waste of measuring it into a cup first. As a digression, I was looking up information on molasses and found the word comes from the Latin root for honey, mel, and comes to us via the French word melasse.

I made my first lamb shank soup of the season. If I am going to shred the meat off the bones into the soup, why do I need to "french" (is it a verb?) the lamb shanks? What's the point? J. Brewster

I want to know where this recipe comes from. The connective tissue around the lower end of a shank adds flavour and lip-smacking texture to the soup as it cooks. Having it frenched (or french trimmed) by the butchersounds like some trade slang for something that wouldn't be discussed in front of a maiden aunt. Tell those in the French camp to allez-oop.

What is the difference between a margherita​ and marinara pizza? W. Grigg

As we discussed recently, a "proper" marinara pizza will not have seafood; just tomato sauce and perhaps a few herbs. A margherita – apparently named after Queen Margherita, who was reigning at the time of Italian unification, by patriotic Neapolitan pizza maker named Rafaelle Esposito – has tomato sauce, cheese and fresh basil leaves. The green, white and red represent the colours of the Italian flag.

Why do some people rave about winter carrots? P. Richardson

Because they're food onanists? That said, root vegetables that are grown in cold areas and remain underground over winter can protect themselves from freezing by changing some of the starch in their cells into sugar. This drops the freezing point of water in the cells. If the carrot were to freeze, the ice crystals would damage the cells, open the carrot up to attack from bugs and microbes and kill the carrot. The benefit for us is that carrots that have experienced cold weather can taste very sweet. When roasted, these carrots caramelise well and can add a depth of colour and flavour if used in a mirepoix, the finely diced vegetables sauteed for sauce-making.

Send your vexing culinary conundrums to brainfood@richardcornish.com.au or tweet to @Realbrainfood.

Brain Food by Richard Cornish is out now from MUP (RRP $19.99, eBook $11.99)