Produce book, pic by Jennifer Soo, jerusalem artichoke
Gas attack: Jerusalem artichokes can be hard to digest. Photo: Jennifer Soo

Richard Cornish

I love Jerusalem artichokes but they give me serious pain. Is there a secret to cooking wind-free artichokes? C. Oliver

If God had meant us to enjoy Jerusalem artichokes without farting like brewery horses then he would have given us enzymes to digest the stuff. Jerusalem artichokes store their energy in underground tubers using a carbohydrate called inulin. Inulin is a polysaccharide. Polysaccharide literally means ''many sugars'', long chains of simple sugars joined together. Starch is a polysaccharide. In our gut, polysaccharides are broken down by enzymes into monosaccharides, or simple sugars such as glucose. Unfortunately, we don't have the enzymes in our guts to break down inulin. So it makes its way intact to the colon, where bacteria take over and digest it for us, in the process creating carbon dioxide gas. Sorry. May I suggest eating a little Jerusalem artichoke at a time to let your body get used to it and not gorge on the first flush, so to speak.

Where can I find black pudding? M. Rogers

Why a sausage made with pigs fat and pigs blood is called a pudding is one of those lovely little etymological digressions we love here at Brain Food. It could have Germanic roots from pud or to swell. I prefer the other derivation on offer, from the French boudin or sausage. Ask black pudding maker David MacDonald at David's Larder (Shop 12, 33-43 Phillip Street, St Marys, NSW) or Rob Boyle from Rob's British and Irish Butchery (177 Lonsdale Street, Dandenong, Victoria).

Do I need to store soy or tomato sauce (ketchup) in the fridge after opening? A. Appleton

Have you ever bought a pie in summer and reached for the squeeze bottle of tomato sauce and pumped your pie full of tingling bubbly sauce? That, my friend, is the result of fermentation and the reason we store sauce in the fridge. With its high acid content, tomato sauce is quite a hostile place for bugs. But once the lid is open, wild yeasts will make their way into the sauce. If the sauce is kept in a warm place, such as on top of the Laminex counter of a country bakery, the yeast could multiply and ferment the sugar in the sauce, turning it to alcohol and carbon dioxide. So once open, keep your sauce in the fridge, especially home-made sauce without additional chemical preservatives. Now, good-quality soy sauce has already been fermented in manufacture, with moulds breaking down the protein in cooked soybeans into amino acids. There's enough salt in soy sauce to stop bugs causing it to go off but once air hits soy sauce, oxygen will start reacting with it, changing its flavour. Keeping soy sauce in the fridge will slow down this process.

What is the best way to store fresh ginger? R. Crowe

When ginger is first picked, it has quite a delicate skin. This is in the markets now so look after it by placing it in a paper bag and keep in the crisper in the fridge. The longer ginger is out of the ground, the tougher its skin gets. This tough skin will protect for a week or so without the quality of the ginger deteriorating. Probably best to buy less ginger more frequently. Some freeze their ginger and grate it as needed from frozen. Our good friends at the Australian Ginger Growers Association suggest buying ginger that is hard and not soft on the ''knobbly bits''. My words not theirs. They also suggest putting smaller pieces in a jar and covering with dry sherry.

Letters

In regards to chicken schnitzels, yes, it was remiss of me not to mention to place freshly crumbed schnitzels in the fridge for at least 30 minutes before frying. Thank you to the dozen people who wrote in. I also need to apologise for describing Monterrey (claimed by some as the birthplace of nachos) as being a state in northern Mexico. Monterrey is actually the capital of the state of Nuevo Leon and home to Manuel Uribe, the world's fattest man. Which makes sense. Thanks to G. Plowes who pointed out that Mexicans eat a nacho-like dish, chilaquiles, for breakfast. This is a dish of toasted tortilla chips served with green tomato sauce, cheese and sometimes cream. Sound familiar? Also thanks to Mr Acroy, who sent in this derisible joke. Q: What type of cheese isn't yours? A: Nacho cheese.

Send queries to brainfood@richardcornish.com.au