My compost pile is in one of my raised beds in my vegetable garden and I don't turn it or get it hot. I have a lot of volunteer plants that grow in it (tomatoes, potatoes, lettuce, etc.) My concern is that since I don't raise the temperature could my volunteer plants be picking up any bacteria and are the volunteers safe to eat. I know, for example, that you have to be careful with melons after you have cut them open so that you don't leave them out on the counter in warm weather. Since I throw the rinds in my compost bin, do I need to be careful?

Are these melons you've raised yourself or bought at the market/grocery store? I always wash the outside of any melon I didn't grow myslef to help remove bacteria that may be there (and may be transported to the inside/edible portion of the melon by the knife used to cut it).

Like all other plants, and you, there are bacteria present all the time, you could not exist if there were no bacteria present to help you do what you do. What you need to be concerned about are the potential disease pathogens and while these also are always present it is generally difficult for us to become sick from them as we work harder and harder to eliminate all the bacteria around us our immune systems will allow more of these pathogens to grow and we will become sicker.
Take the common sense precautions, washing all your fruits and vegetables before using them, and allow the good bacteria to work on keeping the bad bacteria under control.

If it never gets hot, how do things like melon rind break down? Are you using a bacterial agent to break them down or are they actually decomposing naturally? Just curious, suspect some heat at the bottom of the heap.

M

The contents of my compost pile break down eventually over time (a long time). When I do turn it, I take out the bigger pieces. Thanks for the replies - they've been interesting.

The heat in a compost pile is a byproduct of the digestion process and is not a necessary part of that process. The faster the bacteria work the more heat is generated and when heat is generated different species of bacteria go to work, thermophilic bacteria. However, material can be composted just as well without ever getting a lot of heat, it is just slower, takes longer.