Measuring gravimetric soil water content is a relatively elementary laboratory procedure; however, the inaccessibility of a laboratory oven makes this activity impractical for K–12 students. The Soil Moisture Campaign (SMC) Project of the Global Learning and Observation to Benefit the Environment (GLOBE) Program was developed to use gravimetric water content measurement as an introduction to earth science research for K–12 students. We have designed and tested a low-budget, low-technology “light-bulb oven” that is affordable enough for use in a classroom. The light-bulb oven was tested by drying replicate samples of four different soil types in the light-bulb oven and in a traditional laboratory oven. The results show that the performance of the light-bulb oven was comparable to that of a traditional laboratory oven.