What Causes My Carrots to Be Bitter?

High Temperatures

• Carrots grow best in temperatures between 60 and 65 degrees Fahrenheit because they are cool-season vegetables. According to the University of Missouri, carrots will have a bitter flavor when temperatures reach more than 80 degrees Fahrenheit. The sugars in the carrots may not have formed or the terpenoids may remain high in the carrots. When temperatures begin to warm outdoors, mulch the carrots to help keep the soil cool. For best results, harvest the carrots as soon as possible.

Aster Yellows Disease

• Aster yellows disease can form on carrots due to the aster leafhopper. When the leafhopper feeds on infected plants for an extended time, its saliva becomes inoculated with the pathogens and can spread the disease, according to Missouri Botanical Garden. The carrot leaves may begin to turn yellow, the carrot growth may slow down and the carrot roots may become bitter. The roots will also have fine hairs and lack color. Manage the disease by removing infected carrots and control the insects by covering the crops with mesh fabric. The Missouri Botanical Garden also suggests removing weeds from the garden because they may contain the disease.

Harvesting Too Young

• Pulling the carrots out of the ground while they are young and tender may result in a bitter or soapy flavor, according to the World Carrot Museum. Different varieties of carrots can have a higher amount of terpenoids, which will form before the sugars in the carrot. When you harvest the carrots while they are young, they may not contain enough sugar, which results in the bitter taste. Harvest the carrots when they are 1/2 inch in diameter and continue to harvest them throughout the growing season only when they are mature. Most carrots reach maturity within 60 to 70 days after you plant them if the growing conditions are right.

Improper Storage

• After you harvest carrots, they need to be stored properly to keep them fresh. Carrots are best stored in the refrigerator crisper drawer away from apples and pears. The Center for Urban Education About Sustainable Agriculture suggests that the release of ethylene gas from these fruits can cause the carrots to have a bitter taste. Trim the tops off the carrots and keep them in perforated plastic bags in the refrigerator for three to four weeks. The green tops only last for two to three days on the carrots and need to be stored separately from them.