Friday, April 25, 2008

Slow Cooker v Pressure Cooker - Nutrients

slow cookerClare of Veg Box Recipes blog is confused about the advantages of slow cookers compared to pressure cookers. Specifically she is confused because:


... the proponents of both pressure cookers and slow cookers claim their method is the best way of cooking food. Both claim that their method preserves the highest number of nutrients and gives maximum flavour.

Can they both be right?

I dunno, Clare. I see the source of your confusion - one cooks really fast, the other cooks really slow. They seem like opposites, so how can they both be the best?

Some nutrients are destroyed by heat, which suggests that slow cookers (which cook at below boiling point) might preserve more nutrients than pressure cookers (which cook at much higher than boiling point, made possible because of the increased pressure). On the other hand, the slow cool cooking process in a slow cooker can lead to loss of nutrients through enzyme action. These enzymes would normally be denatured by cooking, but because it takes longer for a slow cooker to reach the temperature at which that happens, the enzymes have longer to destroy the nutrients.

So where does that leave us? Nowhere, to be honest. I can't find any data comparing the nutrient content of slow cooked v pressure cooked food. If you know of any reliable data I'd love to hear about it. Otherwise all I can offer is an item of faith - a home-cooked meal from fresh ingredients is likely to contain more nutrients than any ready-meal or fast-food meal, regardless of the cooking method.

I have more to say about slow cookers and pressure cookers, so look out for other articles to come. I'd also love to hear (and maybe try) your favourite pressure and slow cooker recipes. Please email me with recipes or hard facts about nutrients.

5 comments:

Wulf said...

Slow cookers are certainly less scary. I've also found they are very good for making stock from a chicken carcass because the liquid isn't agitated too much and therefore remains relatively clear.

Rhys Wynne said...

I don't posses either s slow cocker or a pressure cooker - but many friends rave about the slow cooker, particularly being able to put something together in the morning before work and it being ready when they get home.

I know very little about how a slow cooker works, but how efficient is it to have an electric appliance on all day - does it use a lot of electricity, or not as it low heat I wonder.

Wulf said...

I don't think a slow cooker uses a lot of energy although, in many cases, leaving it on all day is too long.

Cooking inevitably uses some energy but it would help if people took measures to reduce that. For example, a few minutes on my gas hob can be used to ensure the ingredients going into my slow cooker start off hot (and have the browning and flavour enhancement that comes from that method). I work close to home so can set a stew going at lunchtime and it will be ready for the evening.

I have also discovered that you can slow cook a chicken and then finish it off in the oven to brown and crisp the skin (a handy way of working Sunday lunch around going to church). It is a compromise between energy and taste but comes out pretty well in both stakes.

Melanie Rimmer said...

A slow cooker is a very energy efficient way to cook. It takes a certain amount of energy to raise a pint of water by one degree centigrade. But when it gets to 100 degrees, it doesn't take the same amount of extra energy to get to 101 degrees. Instead, it takes a whole bunch of energy to go from 100 degrees (not boiling) to 100 degrees (boiling). A slow cooker saves energy because the food never gets to boiling point. The price you pay is that it takes longer for the food to cook. But even so, it takes much less energy to cook a casserole in a slow cooker than to cook the same casserole in the oven or on the hob.

Jo said...

I've recently acquired a slow cooker and am hopeful that we can learn to use it to cook some really good meals that can cook while we are out at work. The emphasis has also really got to be on economical cooking.

When you post some recipes for slow cookers - please can you make a couple of them idiotproof beginner recipes? Pretty please?

Thank you!