Unpasteurized honey is safe for most healthy adults. Honey’s natural acidity, low moisture content, and antimicrobial compounds make it inhospitable to most harmful bacteria, which is why it can last for decades without spoiling. The two groups who should avoid it: infants under 12 months and people with weakened immune systems.
What Makes Honey Naturally Resistant to Bacteria
Honey is roughly 80% sugar and less than 20% water. That extreme sugar concentration pulls moisture out of bacterial cells through osmosis, effectively killing most microorganisms that land in it. Honey is also acidic, with a pH typically between 3.2 and 4.5, which further discourages bacterial growth. On top of that, honey produces small amounts of hydrogen peroxide through an enzyme that bees add during production. This combination means that common foodborne pathogens like E. coli, Salmonella, and Staphylococcus aureus cannot survive or reproduce in honey.
Lab studies confirm this. When researchers test raw honey against a panel of bacteria, it consistently inhibits their growth. Certain varieties are especially potent. Manuka honey, for instance, contains a compound called methylglyoxal at concentrations 100 times higher than conventional honeys. Levels above 150 mg per kilogram are directly responsible for manuka’s unusually strong antibacterial properties.
The One Organism Honey Cannot Kill
Clostridium botulinum spores are the exception. These dormant spores can survive in honey indefinitely because they’re resistant to honey’s antibacterial defenses. In a healthy adult gut, the spores pass through harmlessly. Your established gut bacteria, stomach acid, and immune system prevent the spores from activating and producing toxin.
Infants under 12 months are a different story. Their gut microbiota is immature, their stomach acid is weaker, and their intestinal bacterial flora is limited. If a baby ingests botulism spores, those spores can colonize the intestines, germinate, and produce a neurotoxin that blocks nerve signals to muscles. This causes a descending paralysis, typically starting with poor feeding, weak crying, and a “floppy” appearance. Infant botulism is treatable but serious, and honey (pasteurized or not) should never be given to babies under one year old. Pasteurization does not destroy botulism spores.
Who Should Avoid Unpasteurized Honey
Beyond infants, people with compromised immune systems should stick to pasteurized honey. Memorial Sloan Kettering Cancer Center specifically lists unpasteurized honey among the foods to avoid for patients on a neutropenic diet, which is designed for people whose white blood cell counts are dangerously low from chemotherapy or other treatments. The concern isn’t that honey is inherently dangerous but that an immune system unable to mount a normal defense could be overwhelmed by organisms that a healthy body handles easily.
This applies to organ transplant recipients on immunosuppressive drugs, people with advanced HIV, and anyone whose doctor has placed them on dietary restrictions due to immune function. If you fall into one of these categories, pasteurized honey is the safer choice.
Allergic Reactions From Pollen in Raw Honey
One risk unique to unpasteurized honey is its pollen content. Commercial pasteurized honey is heated to around 78°C (172°F) and heavily filtered, which removes most pollen grains. Raw honey retains them. For the vast majority of people this is harmless, even potentially beneficial. But if you have a known allergy to certain weed pollens, particularly from the Compositae family (which includes ragweed, daisies, and sunflowers), raw honey could trigger a reaction.
The mechanism is cross-reactivity: your immune system recognizes pollen proteins in the honey as the same allergens you react to in the air. Reactions range from mild oral itching to, in rare cases, full anaphylaxis. A case report documented a child under six with Compositae pollen sensitivity who experienced anaphylaxis after eating artisanal honey. These cases are uncommon, but if you have severe pollen allergies, it’s worth being cautious with raw, unfiltered varieties.
What Pasteurization Actually Changes
Pasteurization heats honey to about 78°C for six minutes. This kills yeasts and molds that can cause fermentation, which extends shelf life and keeps honey looking clear on store shelves. It also slows crystallization, which is a cosmetic issue rather than a safety one.
The tradeoff is that heat degrades some of honey’s beneficial compounds. Research published in Foods found that pasteurization at 78°C “effectively eliminated the microorganisms in honey but compromised its physicochemical quality and antioxidant activity.” Enzymes that produce hydrogen peroxide, trace vitamins, and antioxidant compounds are all sensitive to heat. A milder heat treatment at 55°C preserved more of these properties but was less effective at eliminating microorganisms.
For a healthy adult, the microorganisms in raw honey aren’t dangerous in the first place. So pasteurization solves a problem you don’t really have, while reducing the compounds that make honey interesting nutritionally.
Storage and Shelf Life
Unpasteurized honey, stored properly, is safe to eat indefinitely. It will darken over time and eventually crystallize, but neither change affects safety. Crystallization is just glucose molecules forming solid crystals as water separates out. If your honey turns cloudy or grainy, place the jar in warm water and stir until the crystals dissolve.
Store honey at room temperature in a sealed container. Refrigeration accelerates crystallization without adding any safety benefit. The “sell by” dates on honey jars are inventory management tools for retailers, not expiration dates. Honey that has been stored for years or even decades remains safe as long as moisture hasn’t gotten in. The one sign of actual spoilage: if honey foams or smells like alcohol, fermentation has started (likely from excess moisture), and it should be discarded.
The Bottom Line on Safety
For healthy adults and children over one year old, unpasteurized honey carries no meaningful safety risk. Its natural chemistry keeps it remarkably free of harmful bacteria. The people who need to be careful are parents of infants, individuals with compromised immunity, and those with severe pollen allergies. Everyone else can choose raw or pasteurized based on taste and preference, knowing that raw honey retains more of the enzymes and antioxidants that heat processing diminishes.