For this mini-experiment, I measured out exactly 4 pounds of Kirkland-brand honey into each of a large cookpot and the liner of my Instant Pot before I started, since I was aware that I would lose quite a lot of water to evaporation while cooking on the stovetop. After that, I cooked both batches for an hour, one at medium-low temperature with an open pot, and the other at the Instant Pot’s High pressure setting.
Once the cooking was done, I allowed both batches to cool to room temperature. The stovetop honey (left) had hardened to a candy-like consistency due to water loss, and had had the chance to accumulate little burnt bits of sugar as well. The pressure-cooked honey remained runny due to almost no evaporation having taken place, but had reached the same dark caramel colour as the stovetop honey. I ended up needing to boil the stovetop honey again with some water to soften it and get it to pour out into a bucket.
Upon tasting, I noticed that the flavours of both batches had deepened considerably. Also, the stovetop-cooked honey had some toasted/burnt sugar notes to it, which was to be expected on account of tiny bits of the honey scorching at the edges of the pan. In contrast, the pressure-cooked honey just ended up tasting more intensely like itself, with some caramel richness to it. Both batches had lost the nuances of their original honeys, which was also to be expected after such high heat for such a long time.
I’ve started meads with both batches using the same recipe of 4 pounds honey per Imperial gallon of must and Lalvin D-47 yeast. I noticed that, upon aeration, the foam of the stovetop-cooked batch was a distinctly warmer, redder colour than that of the pressure-cooked honey. I don’t think I have any reason for that, but I just thought I’d note.