Since the cooking time is so specific, presumably the temperature of the eggs makes a significant difference? Is the 6 mins 50 secs for room temp...

I have the same question, especially since I live at 6000 ft elevation. For most recipes I add 15-20%. I guess I can experiment and see.

Cider vinegar seems closest to me, but rice vinegar would work too -- the soy sauce is definitely dominant, so you can go with your gut without regrets.

I have everything to make these except the sherry vinegar. I could have sworn I had some, but 10 minutes of staring at my pantry didn't produce it. I have rice wine vinegar, balsamic, red wine vinegar, malt vinegar, lemon juice, like juice. I'm leaning towards the rice vinegar, but it's so mild. For those who have tried it, what would you use, or should I suck it up and go to the store?

I usually go straight from the fridge, although the ones pictured might have been sitting out for about 20 minutes while we took photos -- so they're usually just a tad runnier.

I have not made this, but I like my hard boiled eggs to look like that. I also go just under 7 minutes. I would say my eggs are out of the fridge for only 20 minutes, so not room temp, but not totally chilled either.

Good question. I'm thinking of making these this weekend and wondered the same thing. I'd guess room temp would be best.