Convention dictates reducing standard oven temperatures by 20°C when using a fan oven. This makes tolerable sense for moderate temperatures and cooking times but for slow cooking at low temperatures it appears to be illogical. The effect of more efficient fan-assisted heat transfer must become irrelevant after an hour or two, and if a recipe suggests 110°C then setting a fan oven to 90°C (below boiling point) could give very different results. Should we correct for this?

If one drops a frozen turkey from a table, it hits the floor. If one instead drops it from space, it burns up in the atmosphere. Thus, there should be one altitude in between from which you can drop it for it to be done when it comes down.

I realize that it's probably going to go black on the outside and still stay frozen on the inside. How can you deal with this? I will accept leaving it for some time after the fall to allow the heat to distribute properly, I will also accept some or a lot of the outside to burn up if the centre is cooked, burned turkey can be removed but I've heard bad things about uncooked bird.

How does this change with the stuffing? Will it help a lot to thaw it?

Jenny Phillips, Warwick England

A Japanese chef told me that I should always chill tempura batter to ensure it remains light, crisp and fluffy after it is cooked. How does chilling achieve this?

Tom Dressler, Amarillo, Texas, US

If, after peeling an onion then topping and tailing it, I wait before chopping it, the middle segments push up and outwards (see photo, right). Why?

Alan Middleton, Weymouth, Dorset, UK

<!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:1; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:0 0 0 0 0 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:6.0pt; margin-left:0cm; mso-pagination:widow-orphan; font-size:14.0pt; mso-bidi-font-size:13.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri; color:black; mso-font-kerning:14.0pt; mso-fareast-language:EN-US;} p.MsoBodyText, li.MsoBodyText, div.MsoBodyText {mso-style-noshow:yes; mso-style-priority:99; mso-style-link:"Body Text Char"; margin-top:0cm; margin-right:0cm; margin-bottom:6.0pt; margin-left:0cm; mso-pagination:widow-orphan; font-size:14.0pt; mso-bidi-font-size:13.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri; color:black; mso-font-kerning:14.0pt; mso-fareast-language:EN-US;} span.BodyTextChar {mso-style-name:"Body Text Char"; mso-style-noshow:yes; mso-style-priority:99; mso-style-unhide:no; mso-style-locked:yes; mso-style-link:"Body Text"; mso-ansi-font-size:14.0pt; mso-bidi-font-size:13.0pt; font-family:"Times New Roman","serif"; mso-ascii-font-family:"Times New Roman"; mso-hansi-font-family:"Times New Roman"; color:black; mso-font-kerning:14.0pt; mso-fareast-language:EN-US;} p.Calibri, li.Calibri, div.Calibri {mso-style-name:Calibri; mso-style-unhide:no; mso-style-qformat:yes; margin-top:0cm; margin-right:0cm; margin-bottom:6.0pt; margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; color:black; mso-font-kerning:14.0pt; mso-fareast-language:EN-US;} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; mso-ascii-font-family:Calibri; mso-fareast-font-family:Calibri; mso-hansi-font-family:Calibri;} .MsoPapDefault {mso-style-type:export-only; margin-bottom:6.0pt; line-height:115%;} @page Section1 {size:595.3pt 841.9pt; margin:72.0pt 72.0pt 72.0pt 72.0pt; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} -->

About 30 years ago, I gave up drinking wine as I always ended with a blinding headache after an evening when wine was served.  It seemed to cure the problem and I was told that it was likely to have been the sulphides (preservatives) that had caused the effect.  It obviously saved me a lot of money.  Recently, however, my wife asked me why, when she uses wine in the cooking, I do not suffer the same effect ?  I confessed that I do not know.  Can you explain ?

I've recently been trying to lose weight and am rather pleased with the results. However, there is one instance every day when the craving for food becomes almost agonising.

I have to pass a small food stall in the morning which serves bacon sandwiches. The smell drives me crazy and I'm desperate to buy one, so much so that I've changed my route to work to avoid it.

A vegetarian friend also tells me that the one smell that could almost make her start eating meat again is that of bacon grilling.

So what has cooking bacon got in it that makes it so tempting?

Peter Hodge, Leicester, UK

My girlfriend and I were having an argument the other day. Sometimes when it is cold in the kitchen, I turn in the gas hob to warm the place up. The argument is that she claims that the room gets hotter if you put a pot of water on the hob to boil and let the room get steamy. I disagree and think that the room gets just as hot without boiling a pot of water.

Who is right? Does the room get hotter with the pot of water or does the room get just as hot without it?