Excuse the terrible photo, only the front camera on my phone works and the screen is also cracked to hell and back.
Title sums it up. It's been unfed for about 3 weeks. I've read that the liquid on top is hooch and that it's ok if it turns grey or dark, and that you should probably chuck it before feeding or stir it in for a "tangier" taste.
But how dark is too dark? Is this salvageable, and if so is it worth it or should I start again?
Thanks!
Pour off the hooch. Skim off the top layer of starter. Find some health(ier) starter underneath. Take a teaspoon and in a clean jar give it a good feed. If it responds well then you're fine.
There's no mould (red mould to be particularly wary of) and if it has died then it won't respond well to a feed.
As Debra Wink said "if it looks and quacks like a duck - it's a duck".
As long as there is no mold and it doesn't smell like old cheese (or really smelly feet) you should be able to revive. Yeasts tend to go dormant in bad environments but can re-emerge when the environment improves. So dump the hootch, carefully scrape off and discard the top 90% and put the remainder in a clean jar. For the first feeding, add the flour and water and wait till there is some sign of life before doing the second feeding. Just stir it in, keep it warm and wait for some sluggish bubbling. No more feeding-just stirring once a day- until it appears more active, otherwise you are just diluting it out. I might even do a second feeding when it is definitely starting to bubble before I start a discard/feed cycle. It will take multiple feedings and a holding temp in the 75-85F range (in the microwave with the light on) to come back.
As for how much flour/water for a feeding-I have never measured and defer you to other posts where they weigh and measure it all. I add bottled spring water to the remainder of the starter and stir until it is like crepe batter (very thin). Then I add enough unbleached AP flour (cheapest) to make a very thick pancake batter. For reviving I might make it a little thinner or add rye flour but for long term refrigerator storage I would thicken it to biscuit dough consistency.It's hard to kill. It may act differently or smell differently than the original starter because you have changed the inhabitants but if it was a well-performing mix before, it will be fine now.
An important suggestion is to keep the sides of the jar clean as that is where unwanted bacteria and mold will develop. After the rise, stir it down and scrape and then clean the sides of the jar. I use a wet papertowel as the final clean before I tuck it away in the refrigerator.
If you really want to juice it up, include a little stone ground rye in the feeding. That is candy to a starter. It really wakes it up.
I once revived a dried starter that was 40-50 yrs old. Woke right up and is one of my favorite starters.