help with making yogurt in oven

[Guest guest]

I have a yogurt maker, but it doesn't make big batches, which leads me to making

yogurt every other day. I keep going back and forth deciding between getting

another yogurt maker or a dehydrator, but I'm not sure I want to spend the money

yet.

Anyways, I tried making yogurt in my oven last night. I switched out the bulb to

a 75 watt and left the light on. When I checked the temp of the yogurt this

morning, it was only 80 degrees. So I turned the oven on to the lowest temp for

a few minutes and it did get up to 100, but when I checked it later, it was

going down again.

How do you keep the temperature high enough in the oven? I am using one of the

newer energy efficient light bulbs, so I'm wondering if maybe that doesn't give

off enough heat? I had a really hard time believing that any kind of light bulb

would keep the oven to 100 degrees, but maybe I'm doing something wrong.

Does anyone have experience with making yogurt in the oven? I'd love to frugal

and be able to make large batches of yogurt in the oven if possible.

Thanks!

Amber