Consuming contaminated hummus can result in a foodborne illness. Hummus is a popular dip made primarily from chickpeas, tahini (ground sesame seeds), lemon juice, and garlic. Like any ready-to-eat product that is not heated before consumption, it can become a vehicle for bacteria if not handled properly. Product recalls and outbreaks have confirmed that this dip is susceptible to contamination by various pathogens.
How Hummus Becomes Contaminated
The primary ingredient that introduces risk into hummus production is tahini, a paste made from sesame seeds. Sesame seeds are a low-moisture food where bacteria like Salmonella can survive for extended periods. Contamination with Salmonella can occur during harvesting or processing before the tahini is made. When contaminated tahini is mixed into hummus, it can lead to outbreaks of salmonellosis, which has been linked to tahini-based products worldwide.
Cross-contamination during preparation, both commercially and at home, is a major vulnerability. Hummus is a ready-to-eat food consumed without a “kill step” like cooking, making surface or utensil contamination a direct risk. Pathogens like Listeria monocytogenes can be introduced from the processing environment. Listeria is a concern because it can grow even at refrigeration temperatures and has been a factor in multiple hummus recalls, causing serious illness.
The third major factor is temperature abuse, which involves keeping hummus out of refrigeration for too long. Hummus is a perishable product that supports the growth of harmful bacteria, including Listeria, once mixed. The creamy, low-acidity environment allows pathogens to thrive quickly when the temperature rises above 40°F (4°C). Improper cooling, insufficient refrigeration, or extended time at room temperature creates ideal conditions for microbial multiplication.
Symptoms and When to Seek Medical Attention
Consuming contaminated hummus can result in food poisoning, with symptoms typically involving the digestive system. Common signs include nausea, vomiting, stomach cramps, diarrhea, fever, headache, or general weakness. Symptoms can range from mild to severe, often starting a few hours to several days after ingestion, depending on the specific pathogen involved.
Most mild cases of food poisoning resolve within a day or two with rest and fluid intake to prevent dehydration. However, certain symptoms require immediate medical attention. Seek care if you experience diarrhea lasting longer than three days or if you are vomiting so frequently that you cannot keep liquids down. A high fever, defined as a temperature above 102°F (38.9°C), is also a warning sign.
Signs of severe dehydration warrant medical intervention. These include:
- Dry mouth and throat.
- Little or no urination.
- Feeling dizzy or lightheaded when standing up.
The presence of blood in your stool is a serious symptom that should prompt a visit to a healthcare professional. People who are pregnant, older adults, young children, and those with weakened immune systems should seek medical advice sooner, as they are at higher risk for severe complications.
Safe Preparation and Storage Guidelines
To minimize the risk of food poisoning, hummus must be kept at a temperature of 40°F (4°C) or below at all times. This applies to both store-bought and homemade varieties, including ensuring the product remains cold during transport. Once a container of store-bought hummus has been opened, it should be consumed within about four to seven days, even if the printed expiration date is further out.
When preparing hummus at home, use fresh, clean ingredients and maintain sanitary surfaces to prevent cross-contamination. Homemade hummus lacks commercial preservatives and has a shorter shelf life, typically lasting only three to five days in the refrigerator. Always use a clean spoon or utensil to scoop hummus, avoiding the introduction of bacteria from dirty implements.
The “two-hour rule” dictates that hummus should not be left out at room temperature for more than two hours. If the ambient temperature is 90°F (32°C) or higher, this safe period shrinks to just one hour because bacteria multiply rapidly. After serving, any remaining hummus must be promptly transferred back to the refrigerator in an airtight container to maintain its freshness and safety.