Unheated, “raw” honey contains all the vital ingredients that give it its healthful properties and wonderful aroma. Most commercial honey you see in supermarkets is not raw honey. This mass produced honey is often heated to temperatures far above the normal temperatures of the bee hive. Heating past the maximum hive temperature of 95 degrees Fahrenheit changes honey’s essential composition and degrades its quality. It partially destroys honey’s beneficial enzymes and ‘boils off’ volatile compounds that account for the unique, delicate floral aroma of the honey. This is done to make it easier to extract from the honey comb, to filter it, to package it, to ‘pasteurize’ it to kill benign yeast and prevent fermentation and to delay crystallization.

Micro-filtering also degrades the healthful properties of honey by removing beneficial pollen residue. Much commercial honey is micro-filtered, often using a diatomaceous earth (DE) process to eliminate even micron-sized particles. Why go to these lengths when a relatively coarse strain would result in a clear, visually beautiful product and not remove healthful pollen? The reason is to slow down the naturally occurring crystallization of honey. Tiny particles act as ‘seeds’ for the crystallization process, by removing them with micro-filtering, crystallization is delayed.

But crystallization is not a problem to be solved. Almost all honeys crystallize after time. It is actually a good sign the honey is raw. To re-liquify, simply heat the honey jar in warm water (104 F, 40 C) until it returns to the liquid state, stir occasionally to transfer heat, and replace the hot water if needed. Note some honeys will not crystallize easily because of low glucose levels and in these cases, this is not a sign of heating or micro-filtering (ex. honeydews, black locust-acacia, tupelo, sourwood, sunflower, sage).

A good trick to ensure you are getting raw, unprocessed honey is to purchase it in the comb.

Health Benefits of Honey Negatively Affected by Heating

Many of the healthful organic compounds and substances in honey are destroyed or inhibited by heat.

Antibacterial, Antimicrobial Properties from Enzymes in Raw Honey:
The main enzymes in honey are invertase (saccharase) diastase (amylase) which break down sugars and help digestion. The enzyme glucose oxidase produces the antibacterial, antimicrobial hydrogen peroxide, a well-known disinfectant.

Antioxidant Properties in Raw Honey:
Dependent upon enzymes and a wide range of compounds in honey, antioxidants are substances that can retard or inhibit oxidation and/or neutralize the effects of damaging “free radicals”. Increasing the body’s antioxidant content may help protect against cellular damage and the development of chronic diseases.

From the Journal of Agricultural and Food Chemistry 2002, Vol. 50, No. 21, pp.5870-5877:
“…Antioxidant analysis of the different honey fractions suggested that the water-soluble fraction contained most of the antioxidant components, including protein; gluconic acid; ascorbic acid; hydroxymethylfuraldehyde; and the combined activities of the enzymes glucose oxidase, catalase and peroxidase. Of these components, a significant correlation could be established only between protein content and oxygen radical absorbance capacity ORAC activity (R(2) = 0.674, p = 0.024). These results suggest that the antioxidant capacity of honey is a product of the combined activity of a wide range of compounds including phenolics, peptides, organic acids, enzymes, Maillard reaction products, and possibly other minor components…”

Other antioxidants include polyphenols, flanonoids and phenolic acid in Raw Honey. Polyphenols in foods are thought to play important roles in human health such as cancer preventative, and anti-inflammatory, radical scavenging and antioxidative activities. The most important classes of antioxidant polyphenols are the flavonoids and phenolic acids. It is these substances in honey, wine, fruits and vegetables that are most responsible for the antioxidant characteristics, and thus the healthy image of these foods.

Darker honeys like Buckwheat honey are stronger antioxidants compared to lighter honeys.

Source: http://www.honeytraveler.com/types-of-honey/raw-honey/