New Mexico Big Jim peppers can grow up to a foot long and have thick walls with a mild flavor. Most of the peppers grow to be about seven to nine inches long, which is similar in length to the Cowhorn pepper. The plant produces high yields of bright green peppers that are popular for roasting and are frequently called the "green chile." The New Mexico Big Jim pepper is related to the Anaheim pepper and the world famous Hatch (New Mexico) Green Chile pepper, but the Big Jim is the largest of the group. In fact, the New Mexico Big Jim pepper has been named the Guinness World Records largest chile pepper.
The peppers will eventually ripen to red, but many people choose to enjoy New Mexico peppers when they are still green. The green New Mexico Big Jim peppers have less heat and are more flavorful and the mature red peppers are hotter and slightly sweeter. While it’s big in size, the New Mexico Big Jim pepper isn’t big on heat as it averages about 2,500 to 3,000 Scoville Heat Units (SHU), which is similar to a mild Jalapeno pepper.