Trouble with starter- strange smell and texture
help!
I started what was a very robust and healthy starter about 5 years ago and baked weekly loaves with it. I even successfully brought it from Hong Kong to Canada after drying it and rehydrating it 18 months ago. A few months ago we moved into a new house, and the sourdough was bubbly and acting normally. We went away for 2 weeks and it stayed in the fridge like usual. When I took it out to feed, it got a syrupy texture and smelled like cheese. After several feedings and attempts to revive it, I gave up and threw it out. Luckily I have some dried backup stored away so I used that, but the same thing has been happening.
Does anyone know what is happening???
would appreciate any advice. Thanks!
edit: forgot to mention that it was fine at my new house for about a month (I baked a few loaves with it) and it was after we got home from Christmas that it all started to go wrong. I'm currently looking at a newly hydrated batch of back-up starter and it's gone syrupy and smelly too
***UPDATE***
Hello,
I thought I'd provide an update in case anyone was curious.
I followed Mini Oven's advice to use cornstarch when first reviving some saved dried starter. I started to very slowly incorporate wheat flour and bottled spring water without discarding over the next few days. This took place over the course of 10 days or so. Then I started discarding and using wheat flour and bottled water to bring it to a regular feeding schedule.
It's quite warm now where I live, so the starter's been very bubbly and active. Last week, I noticed a faint smell reminiscent of the bad, infected starter I dealt with before, and I added in a quarter teaspoon of apple cider vinegar. That seemed to get rid of the (very faint) smell.
I baked my first loaf with this newly revived starter and it was fine! A little over proofed so not the perfect loaf, but it was not the disaster I had with the infected stuff a few months ago.
Yesterday, I decided to divide it in half, and use half bottled water and half tap water to feed (to determine if the problem source was the tap water). I was involved in a conversation and absent-mindedly put tap water in both! However they both seem to be doing fine so far.
Thanks for all your help!