This is discussed more in the bathroom article, but it is basic hygiene rule that still applies in the bush. It is a simple low impact act that significantly reduces the chances of you and your group coming down with gastroenteritis. Gastro is very high impact, you need to dig lots of holes and quickly, plus may lead to the need to change your trip plans or even to an evacuation. Much easier to wash your hands.
Use a stove
The use of a fuel stove is preferred over a fire for cooking as fire (see lighting fires for more info on why fires should be avoided). Even if you are planning to have a fire, cooking on a stove still generally create less waste and will require less timber. Stoves are generally safer and give much more control over cooking meals. Stoves can often be used in environments where fires can't (eg in the entrance of caves, in the rain and fuel stove only areas.)
Cooking on Durable surfaces
Durable surfaces like rock or sand will sustain less damage from your use so better to use them then the less durable plants and grasses. Stoves do get hot and can burn the ground below destroying plants and smaller organisms. In areas where surfaces are less durable use previously scared spots or place material under your stove that will not burn and will protect the ground. When cooking in the snow people have a similar problem as the snow melts. A square piece of 3 ply timber does the job nicely.
Cooking is an activity that seems to create a lot of walking around the campsite. In less used campsites this concentrated amount of walking can create tracks and large warn areas. On highly durable surfaces this is less on an issue. Use water bags (like old wine cask or commercial products) so that you only need to go to the creek for water once for the whole group – rather than as many as ten times. Offer to fill up everyone’s water. Also ensure that you have everything you need from your pack and tent so that you do not need to keep going back and forth to get more ingredients etc. Besides it lets you sit back and enjoy the evening more.
Use single pot meals
The use of single pot meals not only meals less weight to carry, but also means less washing up. Less washing up means less contamination to the area.
Some multi pot meals require little washing and contain few contaminates. Consider the specific meal options and the amount of water, washing and contaminates rather than just the number of pots, but the number of pots is a good guide. Consider eating straight from the billy to save washing up plates.
Food and cooking groups
Team up to plan menus and cooking, this not only minimise the weight that you need to carry but also reduces the impact on the campsite. If you cook in groups you can significantly reduce the amount of washing up and waste that is created and also reduce excess walking around the campsite.
Use steel wool (and no detergents)
You simply do not need detergents, so why add them to the environment. Plan your means to avoid large amounts of oil and the detergent is not required. Steel wool is a great little cleaner with warm water. Steel wool seems better that foam based scrubbers as they dry out quickly and hence less likely to grow bugs.
Flick water over a large, exposed durable area.
Always wash up well, it is just as important as washing you hands to avoid the perils of gastro, but to wash up well does not mean that you need to trash the area.
If you have lots of bits in the washing up water best to bury it, but generally you will eat them, or store them for lunch the next day. So with few bits mixed with a lot of water flick it over a large area. 100 meter away from water limits the amount of nutrients getting to the water, nutrients can cause unnatural grow rates. Flick the water on durable exposed areas to maximise the amount of decomposing the sun can do, the UV and heat will dry out the bits and kill off bugs. Spread over a large area minimise the risk to animals in the area been at risk from eating.