Slow cooker 101 (AKA Crock Pot 101 or How to use a slow cooker)

I recently got involved in a discussion on twitter about slow cookers. I have a slow cooker I was bought as a present about 15-16 years ago which is still going strong and gets used when the weather gets chilly and Him Indoors and I want something hot and comforting that doesn't require slaving over a hot stove. Slow cookers are great because you can put them on in the morning, forget about them and come home to lovely cooking aromas and a hot meal. They are also brilliant for making cheap meats into very tasty meals. And because they cook on a low heat, they use very little power. Most models are also inexpensive. Hence they are economic to buy, run and fill, and a time saver. What's not to like?

Old Faithful: still going after all these years!

Anyway, here are my thoughts for the uninitiated about slow cookers. I hope you'll share yours by leaving your comments below! (My heartfelt thanks go to the lovely family members who provided the pictures for this post below!)

Choosing a slow cooker

Please note that I do not recommend any particular make or model of slow cooker. You will need to do your own research and choose according to the features and specifications. I have thought carefully about the factors involved, however, and set out the things to look out for here.

You need a slow cooker which is easy to clean. The process of slow cooking will mean that where the top of the stew starts to dry on, the fluids will cook onto the pan. The last thing you'll want to do is spend ages scrubbing! So you want one with an easily removable cooking pan, which will fit into your sink for soaking. If you have a dishwasher, you will want to check that the pan will fit into your dishwasher rack after soaking. And of course, that it is dishwasher safe!

High end ceramic pan model by Crock Pot

In the USA the most popular make of slow cooker is 'Crock Pot'.  When I say popular, I mean it! So much so, they call all slow cookers 'Crock Pots' (hence the title of this post). These cookers have a ceramic pot in which the cooking happens. The advantage of this design is that the ceramic retains the heat very well, and successfully distributes the temperature to the whole volume of the pan. The result is good even cooking, and the assurance that if you are cooking meat and it has reached a safe temperature for eating, you will not get ill. 

Small size Crock Pot brand machine for dips and starters

There are a number of disadvantages. A stoneware pot can be heavy, and that ceramics are fragile. In the larger models, the size and weight of the pot when filled make it unwieldy. I would not like to have to lug one across my kitchen. If you drop the pot, it will break. You will have to sear meat in another pan since you cannot put the ceramic directly on the hob, and if you subject the pot a rapid change of temperature, it may crack. Crock Pot users may want to visit the official website and check out their wide choice of recipes: http://www.crock-pot.com/recipes.aspx

Large US style ceramic pan model

There are a variety of alternatives; enamelled pots, aluminium, steel and non-stick pots. 

UK model with non-stick aluminium pan

The advantage of many of these alternatives is that they are light and are not as susceptible to breakage. The metal ones are durable and you don't have to worry about cracking. Most of these are designed so that you can sear your meat in the slow cooker pot, which saves on time and washing up. 

Pans with non-stick coating will have to be treated with care. You will have to use a wooden or plastic spoon to stir, and you should never use a knife anywhere near the pan surface. Cleaning will involve care and you should only use scourers which are non-stick friendly and non-abrasive. If you scratch the non-stick, as you continue to use the pan, the coating will start peeling a little at the edges and flake in to your food. I have been told that non-stick coating is not good for you and even that it is toxic. So, look after your non-stick pan, and if it's too much to bother with, pick another design of cooker. 

The pan design and size is not your only consideration. I would advise that you find a model with multiple heat settings. You need 3 if possible: high heat, low heat and keep warm settings. This will make your cooker much more versatile for achieving the maximum number of dishes. And the keep warm setting is very useful for when your dish is cooked, but you don't want it to cool down. After all, it is the repeated cooling and heating of dishes which can lead to food poisoning. If you can keep it at a safe temperature but arrest the cooking process, the keep warm setting is very useful and beneficial for family dining.

Lid manufacture and design is important. The lid should fit well, without gaps or heat will escape, lengthening cooking times and diminishing the safety of the food (see below for my advice on food safety). Plastic lid versions are available, but I question how durable and long lasting a plastic lid will be from prolonged use. Also, despite many plastics being labelled as dishwasher safe, I find that after numerous washes, the shape deforms a little, cloudiness sets in, and shrinkage is possible. I cannot tell you how many plastic 'tupperware' storage boxes I have thrown out for these reasons (I have now given up and wash them all by hand). I would say that glass is preferable for durability and so you can see the contents when cooking. In terms of the design, you will find that vapour comes off the food and condenses on the lid. A domed lid which fits within the upper 'lip' or edge of the pot is a good design, because that condensation will eventually trickle back into the pan, rather than risk falling between the pan and the outer skin, risking water going on the heating element. 

Don't be influenced by the price. It is not necessarily a case of the more you pay the better a machine you will get. It is the features, settings and likely use you will put it to that you need to consider. The bigger the cooker, the longer it will take to heat up, longer cooking time and the more energy used. I would suggest that you think about how many people you will be cooking for. A slow cooker with capacity of 3-3.5 litres will easily make enough stew/casserole for 4-6. 

US slow cookers are sold depending on the capacity in US Quarts. The models are typically 4.5Q 6Q, 6.5Q, 7Q (6 quarts = 5.67l).

Some of the slow cooker models available are rather large. You need sufficient tabletop/countertop space for the slow cooker, allowing a decent amount of space from the wall and other appliances for the sake of safety. Most slow cookers are very safe, robust and reliable. However, if you are leaving the slow cooker on when you are out of the house, you need to make sure there is a space all around the cooker for air to circulate. You do not want the cooker overheating and for there to be nowhere for the heat to escape. That's how fires start.

Preparing your dish for slow cooking

Don't underestimate how long the preparation will take you if you are doing it before going to work. Chopping and peeling onions, garlic and carrots will take more time than you think. And if you are planning on searing meat before putting it into the slow cooker pan, you may want to budget between 20-30 minutes for your overall preparation. But do remember that the preparations of the morning will more than pay themselves off whilst you are off doing whatever it is all day. When it is dinner time, everything will be ready to plate up.

There appear to be a number of websites which are advising that you can prepare all your ingredients the night before, put them in the pan of the cooker, put them in the fridge overnight so that all you have to do the next morning is put the pan on the heater. I am sceptical about this advice. If you have a ceramic pan, then going from cold fridge to the hot element base of the cooker might cause chipping or worse still, cracking of your pan. Then it's game over for your slow cooker. 

Another concern I have is putting uncooked meat mixed with the other stew ingredients overnight. The whole point of a slow cooker is that it cooks gently on a low heat. That heat may not be enough to kill the bacteria which may be in the meat. Unless the meat is brought up to a temperature of at least 60°C (140°F), there is a risk of food poisoning. Ideally to ensure that bacteria, toxins and spores are all killed off, you need a temperature of 70 °C (158 °F). Some food safety agencies are recommending 72-74°C (160-165°F), and there are different guidelines for different meats. (See http://www.foodsafety.gov/keep/charts/mintemp.html and http://www.guardian.co.uk/lifeandstyle/wordofmouth/2011/may/25/pork-cooking-temperatures-lowered). 

    

I would say that if you are pressed for time, and need to use the overnight method, prepare all of your ingredients. Store them in a different container from the cooking pot, and put the meat in a separate container. Then in the morning, put everything into your cooking pot and switch on.

For the same food safety reasons I have set out above, I would advise that you do not put any frozen non-vegetable ingredients in your slow cooker, and if you are tempted to use any frozen vegetables, that you check the whole dish reaches a high enough temperature (adding anything frozen will bring the pan temperature down considerably). 

If you are intending to use beans in your dish, then dried beans will need to be soaked overnight. Some beans contain toxins (like red kidney beans). Even with overnight soaking, if the heat is relatively low on your slow cooker, you may find that even after 6-8 hours cooking, the beans are still hard. By all means, have a test-run if you wish to see if your cooker has enough heat that this is not a concern. Alternatively, boil the beans for 10-15 minutes after overnight soaking.

If you can't be bothered will all the faff of overnight soaking and par-boiling of beans, you can use tinned. However, the cooking time for them must be reduced, unless you like bean mush. You will only need to cook them for 2-3 hours, so you may need to factor in when you will be able to add them, or make dishes without beans in them at all. 

Meat should have as much fat trimmed off it as possible, as the fluid in the pan will keep the meat moist. You will not need the fat to prevent the meat drying out, and any fat will just remain in the dish, which obviously is not healthy. This is one of the reason that the cheaper, leaner cuts of meat are recommended for slow cooking. 

Slow cooker recipes

There are lots of slow cooker recipes, available online or in books. You may need to take care with some recipes. In the USA recipes will follow US conventions on temperature and measurements, and will often assume you are using a Crock Pot - so will use 'high' and 'low' based on the temperature setting that particular brand uses. Whether these setting are the same for all brands, I am not sure. UK recipes tend to use weight measurements, cups and may refer to temperatures in Celsius (°C). You may want to check out cookbooks before you buy if you find it hard to translate from one set of conventions to another.

For the maximum flavour, meat should be seared before putting into the slow cooker. This is not essential, but will make a lot of difference. Experiment with both to see which you prefer and whether the effort is worth the trouble. 

As a result, you may want to take a favourite existing stew or casserole recipe and tweak it for the slow cooker. This increases considerably the variety of what you can make. When adapting a regular casserole recipe, there are certain considerations you will need to bear in mind. You need to think about whether any of the ingredients are going to turn into mush if cooked gently for 6-8 hours. Mushrooms are a prime example. These will need to be added in much later in the cooking process. Other 'softer' vegetables like courgettes may also disintegrate in the pan. 

Another consideration if adapting oven baked casserole or stew recipes is that a lot of moisture evaporates (even with the lid on) in the oven, thickening the sauce. The low temperature of the slow cooker means that you won't lose anywhere near as much liquid. This means you need to reduce the amount of stock/water you use. You may need to add more flavourings (herbs and spices) to avoid a blander taste than you would have got through oven cooking. Finally, if you find the dish is too watery, you can use a mixture of cornflour and water to thicken the 'gravy'.

Watch out when using root vegetables like carrot, swede, turnip etc. These are hard, dense veggies. They may not cook to the point of softness even after 6-8 hours. It may be an idea to soften at the frying/browning stage.

See above for my advice on adding beans and pulses to your dishes.

Try not to take the lid off to admire your handiwork or to stir. You'll lose some of the heat in the pan and this will increase the cooking time. Or increase the chances that your food will not be brought up to the minimum safe temperatures referred to above.

In my research for this post, I was amazed at the sheer versatility of a slow cooker. I had always used mine for stews and casseroles, real Winter warmers. I have now discovered that my trusty old cooker can be used for jam, chutneys, cake, steamed puddings, custard, curry, chilli, soup and stocks!

Kavita Favelle of Kavey Eats has advised me:

"I use slow cooker to make stock, after each roast chicken dinner. I pull all leftover meat off the carcass, then bones, ligaments, soggy skin all go into pot with water and left on overnight. Drain in morning and fridge or freeze, for soup or risotto. Often make risotto with stock and chopped leftover meat. Also, sometimes poach whole chickens in slow cooker."

Kavita also uses her slow cooker to poach a whole chicken. Recipe here:

http://www.kaveyeats.com/2012/04/slow-cooker-poached-chicken.html

This is my recipe for a tomato based slow cooker stew using butter beans and chorizo:

http://snigskitchen.blogspot.co.uk/2012/10/spanish-chorizo-stew-with-butter-beans.html

Here is my slow cooker version of the Spanish classic lunchtime dish Cocido: 

http://snigskitchen.blogspot.co.uk/2011/07/spanish-cocido-la-snig-spanish-chickpea.html

I use mine for mulled wine for Winter parties, which means the wine does not boil or evaporate and I am free to mingle with my guests instead of standing over a saucepan:

http://snigskitchen.blogspot.co.uk/2011/12/christmas-entertaining-slow-cooker.html

More tips for using a slow cooker:

http://domesticservitude.blogspot.co.uk/2012/11/tips-for-slow-cooking.html

Pot roast chicken:

http://www.goodtoknow.co.uk/recipes/516028/antony-worrall-thompson-pot-roast-chicken

A complete one-pot meal of Turkish lamb pilau (almost like a biryani):

http://www.bbcgoodfood.com/recipes/1944/turkish-lamb-pilau

Seasonal slow cookery - how to make cranberry sauce:

http://www.theperfectpantry.com/2012/11/recipe-for-sugar-free-slow-cooker-cranberry-sauce.html

Pudding recipe for treacle sponge adapted for the slow cooker: 

http://www.bbcgoodfood.com/recipes/13352/schooldays-treacle-sponge

A large collection of slow cooker and crock pot recipes:

http://www.momswhothink.com/crock-pot-recipes/crock-pot-recipes-for-the-crockpot-and-slow-cooker.html

What are your slow cooker hints, tips and tricks?