How many times (and ways) can you reheat honey safely?

Question

We have an old house that is quite cold especially in winter. As a result, the bottled honey we buy solidifies in the squeeze bottle. The manufacturer recommendation for this is to gently reheat the bottle (although it doesn't state exactly how).

I have in the past placed the bottle in gently simmering water and even placed it in the sous vide bath @ 60C (140F) which works reasonable well. The only downside is that it takes a good 5 minutes to heat through and I have to dry the bottle off.

I tried tonight nuking it in the microwave for 30 seconds, giving it a good shake and resting for a minute. While not quite as effective as the water method at loosening the honey, it did avoid the hassle of drying the bottle off.

Are there any health risks associated with reheating honey and am I breaking any food safety guidelines by microwaving it multiple times? In both examples I am not reheating all of the honey to a liquid state throughout, just enough to get a portion out of the bottle.

Answer 1

Honey crystallizes in a natural and spontaneous way, specially when stored in low temperature or due to aging. It changes from a liquefied to a semi-solid state.

The recommended way is to heat crystalized honey in a water-bath around 35ºC. It will take a while and you'll have to dry off the honey container. I didn't find any scientific paper mentioning health risks related to heating honey.

Actually this paper says

honey prepared for commercial market is usually heated and filtered to avert crystallization since the heat helps in melting invisible glucosecrystals present, thereby keeping the honey in liquid state for many months.

and

unprocessed (e.g., unheated and unfiltered) honey is prone to fermentation at ambient temperature within a few days of storage; therefore, honey is typically heat-processed prior to storage.

From where we can take the conclusion that heating honey doesn't bear any health risks. With higher temperatures it may improve the antioxidant potential while the antimicrobial activity decreases.

The antimicrobial activity of honey decreased and was even lost with increases in heat treatment. Therefore, though prolonged heat treatment was recommended for enhancing the antioxidant potential of honey, the temperature should be limited to preserve honey’s antimicrobial activity.

comments: by @FuzzyChef:

Confirming that you can reheat honey many, many times, for years, without associated health risks. Honey is a strongly antibacterial environment: Antibacterial Potency of Honey

Answer 2

There are no health risks, but heating the honey may change the honey permanently. Heating honey can destroy or weaken enzymes in the honey.

Most honey makers recommend staying under 95 F (35 C) degrees. If the honey crystalizes, usually heating is the recommended way to revert to a more liquid version of the honey.