Reviving a Starter

I believe you're in the right track. Unless the starter smells totally awful which shouldn't be the case I would do exactly as you described. I would keep it at 100% hydration. That is: add equal amounts of flour and water. I use scales. If you want to leave it overnight I'd use something like 20g of starter, 60 g H2O and 60g flour. I only use rye flour as the base starter, the one I keep in my fridge. When you see some activity after the first period, take a small amount of that batch, i.e. 20g and repeat. You may have to do this 3 or 4 times and then you'll have beautiful, working starter again. If you prefer other flours it is still the same principle, or you can convert later to a starter of your liking.

A lot has been written on TFL about starter maintenance, reviving, etc.

Finally, the starter that you keep in your home and that you restore and maintain takes on the characteristics of your home, the flour that you use, the environment of your place. Although it may have come from a bakery in France after some time it's yours and the bakery in France is nothing but a nice memory.

What every starter needs is (1) food, (2) removal of waste products, and (3) maintenance of the environment, especially pH.

When a starter gets this old, there are a lot of waste products, and the total acidity is high.  So heavy dilutions are very reasonable in this case.

Pour off any clear liquid on top.   I would go 1 part starter, 3 parts flour, 3 parts water (1/3/3) the first dilution, remembering that it will take longer to get active again, so don't panic.   Then work back to your normal feedings.

Clover, after your starter is revived and active it is a good idea to dry some of it and store for a backup. The flakes will keep for years and years. If tragedy stricks you can always restore from your backup.

Dan

I didn't see it clearly stated in the good tips above, so I will add:  Be patient.  If you read that a starter should grow up in 5, 10, 24 or 48 hours, ignore it.  An extremely neglected starter will have a majority of dead cells, a high concentration of their waste products and high acidity that will inhibit growth of the survivors.  Visible recovery can take several days.  I've had to wait 24-48 hours for my starter to creep back to life after I've left it on the refrigerator door for 3-4 weeks while traveling (normally it doubles in 4.5 hrs after a feeding).  But it always comes back.  I don't bother drying it down before trips like that any more, though I do dry some down occasionally as a deep backup.

So be patient.

Tom

As others have said, give a larger than normal feed (1:3:3 or more) and just wait.

In reality it may be a moot point whether this sort of treatment actually revives the original starter, or just leverages the acidity of the dead one to begin a new starter from the microbes present in the new flour. However it matters very little either way, because although the starter originated in France its composition will have changed a very great deal since then, unless it’s been fed the same flour and kept in the same conditions...

imho, you should wait for it to rise, where interior bubbles push the upper surface up.  A few bubbles on the surface is a good sign, but don't get over-anxious.

Here's a thought.  Your 1:1:1 inoculation proportions (33% starter : 33% flour : 33% water) might be a bit high on starter.  That you've chosen to make it (or keep it, if it already was) 100% hydration is pretty standard these days.  But introducing that much of the old starter, carrying as it is a heavy load of unwelcome metabolites (esp the acidic ones) accumulated over the past lonely weeks -- that could slow things. 

But not to fret.  It's a balance.  Given that your moribund starter has a higher than desired proportion of dead cells in it, any inoculation is going to have fewer viable cells than the same volume of a freshly maintained starter.  So reducing that metabolite load (see below) by cutting back that "1/3 starter" to 1/6 or 1/10 is destined set you back in the numbers game.

Yet no harm in this: Set up a second, separate culture from that old starter.  Instead of 1:1:1, as you've done, dilute the starter inoculum more, so that your culture's ratio is 1:3:3 or 1:4:4 or 1:5:5 (my weekly regimen is 1:4:5).  And this time, be especially patient, because you're starting with fewer viable bugs than in your original 1:1:1.  But this time, they're not struggling to reproduce in as acidic and toxic a soup as those in your first try.

Tom

My data shows that a starter that is fed and refrigerated in accordance with Tom's guidance (refrigerator temp=4°C) will continue to replicate for about a month before it has exhausted the available nutrients. After that, there is another period during which both the yeast and LAB slowly die off so that after 6 or 8 weeks it will take more time and more cycles to fully recover it.  However, you do run the risk that yeast/bacteria (not necessarily LAB but acid tolerant) begin to have population densities that are high enough to shift the point of stability away from where you started.  So a week - no problem at all. Don't even need to double refresh before putting it back in the refrigerator. Two to 4 weeks, probably need two and perhaps three refresh cycles to get it ready to store again.  After that I am not sure that you still have the same culture.