Wu

Mostly cosmetic. The pellicle is cellulose the bacteria produce as a byproduct, not the engine. Fermentation happens in the liquid, so a batch that sours on schedule with no new pellicle is fine.

That said 18C is genuinely low and pellicle formation is the first thing to stop, so it's a useful thermometer. If batches start tasting flatter or taking longer, warm it: a seedling heat mat under a towel, a shelf above the fridge, or an aquarium heater in a water bath around the jar. 24-26C is where mine is happiest. Don't just put it in an airing cupboard and hope.

One posture thing: are you leaning forward? On a frameless pack with the hip belt doing little, a slight forward lean puts the whole load on the front edge of the shoulder strap. Standing deliberately upright for a minute and seeing whether the pressure moves tells you a lot.

Flat, wrinkled, white, no fuzz, and it re-forms as a skin after you disturb it. That's kahm yeast and it's harmless. Mould is fuzzy and three-dimensional, grows in distinct circular colonies rather than an even film, and is usually blue-green, black or pinkish. The other tell is that kahm sits on the liquid surface while mould generally starts on something poking above it.

Skim what you can, make sure everything is back under the brine, carry on. It'll return if the ferment is warm and slow. 20C is a bit warm for kraut and low salt plus warmth is exactly the kahm-friendly combination, so next batch try 2.25-2.5% and somewhere nearer 18C.

Honest caveat: fuzz, any colour, or a genuinely foul rather than sour smell means throw it out. Not worth the argument.

The first aid repack is the classic one. Mine went from 240g to 80g by binning the box and putting the actual contents in a small zip bag.

Check the flour too. Plenty of supermarket strong white sits around 11.5% protein, which is fine for a yeasted loaf and quite tight for a long sourdough ferment. Not the cause of seven hours, but it's the difference between an acceptable crumb and a good one.

It was slightly damp both times, now you mention it.

Added a foam pad under the inflatable and slept through 1C without waking. Slightly annoyed at how simple that was.

Midge-specific: check the mesh spec on your inner. Proper no-see-um mesh stops them, ordinary mosquito netting doesn't, and highland midges will find any gap where the mesh meets the groundsheet. That matters far more than which shelter type you pick.

Ferment, and the time cost is lower than you think. About twenty minutes to chop and brine, then two minutes a day of nothing, then twenty minutes to blend and bottle. The result is noticeably deeper and more complex than a vinegar blend, which is bright and one-dimensional by comparison.

The pH meter question is the real one. Brine at 3-3.5%, blend with a decent slug of vinegar, keep it in the fridge, and you're in normal home cooking territory. The moment you want shelf-stable bottles at room temperature to give away, buy the meter, because that's when the number stops being optional. Strips are not accurate enough at the range that matters.

Top of the fridge is the classic move and it works, but check it with a thermometer. Some modern fridges barely warm the top at all.

It gets better and it never fully goes. Fifteen years in and day one still involves an hour of being convinced my pack is broken before my body settles. I treat that hour as part of the trip now rather than a sign something's wrong.