Sourdough in the freezer

[borgr]

I want to leave my sourdough (itself, not baked loaves of sourdough bread) for a while (going abroad) but I do not want it to die, can I leave it in the freezer? do you have other ideas?

[Lisa Shock]

Don't freeze it, dry it.

[cakewalk]

I have frozen and then used the defrosted sourdough. It took a bit of daily feeding to get it up and running, but it worked fine. I'd suggest freezing small amounts in a few containers rather than a large amount of starter in one container. I froze starter made with bread flour and starter made with rye flour. The bread flour worked well, the rye flour never came back to life.  I don't know why. I've never dried sourdough, but that also sounds like a good option. Maybe try both and see how each works?

[DianaM]

What is the hydration of your starter currently? And how long will you be gone?

 

You can make a stiffer starter (dial down the hydration little by little if you keep it 100%) and after the last feed before you go, leave it out on the counter a little while to get it fermenting. Then you refrigerate it. Mine was ok after three weeks in the fridge like this. 

 

Because I love my starter very, very much I also made a "back-up copy" for the freezer. I dried it like in the link above, and then put it in a sealed bag in the freezer. I left it there for a year, and it was still viable after all that time. 

 

[pbear]

I also can report having successfully dried and revived a starter.  Stored in the fridge rather than the freezer.

[paulraphael]

I've read that it's a good idea to get it very active before freezing, since the freezer may kill a good number of the buggers. And maybe not try to keep it frozen indefinitely.

[Deryn]

My mother's sourdough starter was stored in the fridge (and it dried out there 'naturally' in its container) for well over 20 years. I found it as I was getting my father's house ready for sale a few years ago and managed to revive it for a short time before I chucked it out. I made a few loaves of bread and some pancakes but decided not to keep it in the end. Not sure it tasted quite the same as I remember it to have been when Mom was alive - perhaps was a bit 'fridge-burnt' after all those years - but I was impressed that it had managed to survive at all for that long.

[paul o' vendange]

I've abused plenty of starters while away, and am always amazed at their resilience.  Keeping in mind that any change to any ambient factor will alter the balance between various strains of yeasts and bacterias, I've left things to "rot" in the fridge for as long as a month, with a viable culture on returning - just took deliberately under-inoculating the 12-hour ferments to encourage lots of young growth (i.e., lots of generational growth as opposed to mature, anaerobic fermentation) over the course of several days.  The first, very little inoculation and 24-hour cycles, then as the culture starts exhibiting good strength, I go to greater inoculations and 12-hour shifts.

 

Freezing will do the same.  It will preferentially favor some species over others, and your balance will shift, yielding a different poolish and final bread.  But if you return to your regular routine, on your return, eventually your population mix will re-adapt to your ambient conditions, and you'll be back in business.