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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

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    • CommentAuthorSprocket
    • CommentTimeOct 13th 2013 edited
    We have one of our own sheep in the freezer (a long story, for another time).
    It is very tasty but a bit old and tough
    So we decided we need a slow cooker.

    But I am a bit disappointed to see how poorly insulated most of them are. Reviews regularly talk about people burning themselves on them. I don't know if I can bring myself to buy something so inefficient.

    I remember Blue Peter back in my youth demonstrating how to slow cook without power by placing your casserole dish in a cardboard box full of straw... or was that how to hibernate your tortoise? Maybe I am getting them mixed up.

    Anyway, it seems to me that if you put 150W into a slow cooker and eg. 100 watts is leaking out as heat this is not a very efficient way to cook. And they all seem to just have two settings (high and low) with no indication of just how much heat they put into your food... no temperature gauges. How are you supposed to know how long is long enough? Why aren't they better insulated? Why aren't they better instrumented? Why can't I find a slow cooker targetted at people like us? Is there such a thing?

    Also considering vs just cooking in a casserole dish in the regular oven at 100C. That surely wouldn't leak as much heat into the room?

    I searched these forums for slow cooker first but didn't find anything so thought it worth asking.

    I did find a navitron thread

    and I found this which was interesting

    Anyone got any thoughts or handy hints on low energy cooking, slow cooking etc and associated kitchen tools or appliances?
    • CommentAuthorTimber
    • CommentTimeOct 13th 2013
    I have a slow cooker - and no it has no insulation at all, but the power input on low is really quite small. You could insulate it, but then there is no thermostat on mine, so it would get hotter and not slow cook anymore.

    I am convinced, even with the heat leakage, that it is still more efficient to use a slow cooker than the oven. And after all, all energy you put in comes back out again at some point.
    Hi Sprocket,
    I've used a slow cooker for years. They come with recommended cooking times - but I have found give or take a couple of hours is O.K. and the low setting can be used to keep it warm. It's always disapointed me that they are not better insulated. May be they should just be a well insulated box that a boiling casserole is put into.

    My partner is a fan of the halogen cookers - just a glass bowl and a halogen heater with fan. About £40. We use this for most "oven" cooking. We also use it for slow cooking (125 C about). Lamb and pork/crackling are perfect 4/5hours. A normal roast chicken is about 1 1/2 hours. I have not measured the energy used - but would be interested if anyone has the figures. One problem is most halogen worktop ovens only have a 1 hour timer and you can't just leave it on for more than this unattended.

    • CommentAuthorSeret
    • CommentTimeOct 13th 2013
    Posted By: Timber
    I am convinced, even with the heat leakage, that it is still more efficient to use a slow cooker than the oven.

    They really come into their own with PV, where they shift the big peak that would come with an oven at the end of the day, and turn it into a small constant load when the PV is available.
    • CommentAuthortony
    • CommentTimeOct 13th 2013
    Hay box?
    • CommentTimeOct 13th 2013
    I killed my tortoise by keeping it in a shoebox in my bedroom cupboard. Took months to find out what I had done.

    For any given mass of food to be cooked it will take a certain amount of energy. Not sure how important the time it takes took is.

    There was a bit on Radio 4 about pressure cooking

    My slow cooker, the plastic brown one with an aluminium inner into which a brown crockery pot was places never got very hot. The lid was the hottest part, but the smallest exposed area.
    ''I killed my tortoise by keeping it in a shoebox in my bedroom cupboard. Took months to find out what I had done.''

    Yeah, but I bet it was done nicely by then.

    Tony mentions hay-box cookery. Heard of someone a few years ago (on R4?) who uses a duvet instead. Any insulation would do instead.
    • CommentAuthorskyewright
    • CommentTimeOct 14th 2013
    Posted By: tonyHay box?

    Yes, that's the term.

    Here's someone who uses the idea (but Celotex rather than hay!)...

    • CommentTimeOct 14th 2013
    I have cooked Pasta by putting it into a thermos flask, filling it up with boiling water from the kettle, pop the lid on, give it a good shake, leave it for 15 to 20 minutes, done.
    • CommentAuthorEd Davies
    • CommentTimeOct 14th 2013
    As I wrote in the Navitron thread referenced above (under the pseudonym EccentricAnomaly):

    I've cooked pasta in a vacuum flask as an experiment. It cooks more slowly than in a saucepan on a hob which is OK but makes it difficult to work out when it's done. Finished up with a soggy overcooked result a couple of times. It's worth bearing in mind that the actual cooking process absorbs energy (to break chemical bonds) so even in a hypothetical perfectly insulated container the food will cool.
    Also worth noting that cleaning out the vacuum flask safely is a bit tricky.
    • CommentTimeOct 14th 2013
    My thermos isn't, it is a cheap, all stainless, one from Pountstretchers.

    Does take longer, about twice as long. The shaking is important.:bigsmile:
    • CommentAuthorSprocket
    • CommentTimeOct 14th 2013
    OK, we have bought an insulated electric cooker with a thermostat (a Lakeland "Superchef").
    It looks a bit like an electric rice cooker - as found in all Japanese kitchens.

    But it only has one "slow cook" setting. This seems to be fixed at 80 degrees.

    It does also have a manual mode in which you can set the temperature and time. But we don't know what sort of temperatures would correspond to the "low" and "high" referred to in slow cooker recipes.

    If anyone with an IR thermometer happens to find themselves slow cooking perhaps they could measure the food temperature and let us know.

    PS: Just doing a chile. Was interested to note that fresh (as opposed to tinned) red kidney beans contain a toxin that is destroyed by boiling for 10 minutes BUT some slow cookers only get to 80 degrees and this apparently actually makes the kidney bean toxin MORE poisonous. I read on that internet that even four or five beans can be pretty harmful.
    • CommentTimeOct 14th 2013
    You need to cook at above 70°C to kill of the things that will kill you. Everything I cook in the restaurant has to be checked and logged down for the Health Inspectors. Nothing below 70°C is allowed, regardless of how it looks (burnt usually). All my paperwork is up to date as not been checked this year, only a matter of time till we are.
    • CommentAuthorskyewright
    • CommentTimeOct 14th 2013 edited
    Posted By: SprocketOK, we have bought an insulated electric cooker with a thermostat (a Lakeland "Superchef").
    It looks a bit like an electric rice cooker - as found in all Japanese kitchens.

    Ah. Them. Very popular with the HK Chinese students I shared a house with at uni too.

    Nowadays we use one of theseL
    (well, actually we use the previous model, which was transparent).

    Over time we have developed this formula: 6 minutes on full (1000W inverter microwave), stir, 5 minutes on medium (600W), 7 minutes standing, stir, drain off excess water. That's for 3 cup fulls of rice. With less rice you could probably alter the full/medium balance.

    While we were waiting for it to arrive we tried the basic technique of using a microwave for rice cooking just in a normal casserole dish. Worked fine, but as we have the Lakeland pot we now use that (having the inner & outer pots does have some advantage & convenience).

    On the same subject, our formula for quinoa is even simpler. 300ml into a 1l casserole. 450ml boiled in a kettle. Pour into casserole. Heat in 700W microwave for 2 minutes. Stir. Heat in 700W microwave for 40 seconds (just enough to return it to the boil). Stand. By the time we are ready to use it the 1l caserole is brim full of quinoa.
    • CommentTimeOct 15th 2013
    Posted By: SteamyTeaEverything I cook in the restaurant
    Another clue!
    • CommentTimeOct 15th 2013
    Pretty handy with a skillet and a sharp knife.

    Anyone up for having a 'cooking competition'.
    We coudl all decide to cook 50g of the same sort of pasta until it is al dente, see who uses the least energy. Be a giggle and only take a few minutes.
    Then we can compare notes after.
    • CommentTimeOct 15th 2013
    There's dentes and dentes.
    • CommentAuthorSeret
    • CommentTimeOct 16th 2013
    Yes, no sharpening your teeth. That's cheating.
    • CommentTimeOct 16th 2013
    • CommentAuthorcaspen
    • CommentTimeOct 22nd 2014
    Belated addition - moer than 10 years of cooking this way. I use an insulated duvet drawer now that we have a new kitchen ie leftover celotex underneath and around and a duvet on top. Before that, I used a cushion, add layer of newspaper so that I didn't burn the cushion, place hot pot with lid on, cover with duvet or another big, heavy cushion.
    The recipe ...
    white rice - 1 cup of rice to 1.5 cups water - bring water to the boil, then add rice, bring back to the boil, reduce to simmer for 5 mins, put in duvet drawer for 2 or more hours
    brown rice - as above but double the water
    beans - bring to pressure in the pressure cooker, cook for half the recommended time, allow pressure to reduce to normal, put in duvet draw for a couple of hours or more - to suit
    soup - bring to boil, simmer for 5-10 mins, move to duvet drawer
    You get the idea!
    • CommentAuthorowlman
    • CommentTimeOct 22nd 2014
    Aha, Mariette. Haybox 2014 style :bigsmile:

    • CommentAuthorWeeBeastie
    • CommentTimeOct 22nd 2014
    For those who don't sew/build. Bulky though.

    • CommentAuthorCWatters
    • CommentTimeOct 22nd 2014
    Looks like Thermos make a vacuum insulated cooking pot. Not sure if available here. Those on Amazon appear to be Japanese imports.
    just wait until the heating season before cooking casseroles and such. Any oven cooking or such like seems a huge waste in the warm months.

    Put the casserole dish in the bottom of the bed under the duvet - warms your bed and slow cooks at the same time. Nice warm feet when you go to bed.
    • CommentAuthorowlman
    • CommentTimeOct 22nd 2014
    Just don't do it when you've had a skinfull otherwise you may wake up thinking there's been a terrible accident.:bigsmile::wink:
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