The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Starter turns to junk after 2 weeks

djbrasier's picture

Starter turns to junk after 2 weeks

I've had basically the same problem for three tries of making starter.  Here's what happened the last time:

Day 1: Mix equal parts locally sourced whole wheat flour and orange juice

Day 2 & 3: repeat

On day 4 the starter is super active.  So much that I can bake a round loaf using just what I would've discarded.  It rises beautifully and (aside from the hint of orange juice) is delicious.  The rise is as good as anything commerical.

Day 4: feed 1:2:2 starter:flour:water by volume.  I use filtered water that's been sitting out for at least a few hours.  The flour is a 3:1 mix of King Arthur AP and the same locally sourced whole wheat from the Farmer's market that I used to start the starter.

Day 5-8: repeat

On day 8 the starter still looks beautiful.  I bake another loaf using 400 g 100% hydration starter, 300 g King Arthur AP flour, 125 g water and 10 g salt.  The loaf rises beautifully, gives great oven spring, all is happiness.

I leave the starter at room temperature, feeding daily, discarding unused portions of starter.  By day 13 however, it's gone from looking like a beautiful poolish after feeding to smelling foul and having tiny bubbles without really moving at all after feedings.  On day 13 I try making a loaf using the same formula I used on day 8.  This one doesn't rise at all, even after 12 hours at room temperature with me checking on it every couple hours.  I try to bake it anyway late that night, but it is just a snotty mess of dough.  The product tastes sour, but is basically a hockey puck.

Basically the same thing has happened the last 3 times I've made starter.  Is it salvageable at this point?  Is there something I'm doing wrong here?  I suspect that the bacteria are beating out my yeast, but I can't figure why or how to stop it.  Any help would be greatly appreciated.


DJ Brasier

rick.c's picture


It seems like you have the method down well enough.  I would suggest switching to weights insted of volume measurement.  Or, if you don't have a scale, try a 1:2:1 by volume refreshment starting on day 5.  Water is ~2X more dense than flour, so this should keep you ~100% hydration.  My only other thought would be to try rye flour, it does better.  Hopefully someone with more expertice can offer more help if this doesn't work.


SourdoLady's picture

Your starter is starving. When keeping a starter at room temperature you either need to feed it 2-3 times a day or give it much larger feedings so it has enough food to last that long. It is also important to discard all but a spoonful or two of the old unused starter before feeding. This gets rid of the excess acid, which is most likely what is causing your problems. Once you get that starter healthy again, I would suggest that you keep it in the fridge in between usage, unless you are using it every day.

Daisy_A's picture

First of all congratulations on getting gorgeous loaves on day 4!

However if your starter is able to do this it may be a very vigorous one so one cause of its decline may be that with daily feeds only at 100% the yeasts may simply be working through the available 'food' too quickly.

My recently cultured starter also changed in nature around the two week mark. From smelling of peaches and wheat and rising well it started to become thinner and to smell of acetone, something I now recognise as a sign of underfeeding. Following Sourdo Lady's instructions on this site I started to feed it more regularly and increased the ratio of flour to water to produce a stiffer consistency. I also plucked up the courage to discard more, something that I had been nervous of doing up to that point. Following advice on this site I also moved from volume to weight measurement, which allowed me to judge the ratio of starter to flour to water much more accurately.

However the starter still smelt of acetone so I 'washed' it following instructions similar to those posted by 'Alpine' (second to bottom), on this thread I kept some starter as a backup and went down to only 50 grams in a cup of water (some people advocate a tablespoon). This was risky, but my starter was vigorous enough to take it and after 3-4 washes was behaving well and smelling of fruit and wheat again.  With this method you have to be very careful about temperature as over 90F can kill the yeast. I tested temperature with a sugar thermometer. However, if you are throwing away your starters anyway it is probably worth a go if you're still having problems after feeding it more regularly.

My starter has remained fine after its 'wash' and I have worked out from this that because it is vigorous it needs lots of flour to chomp its way through. I now feed a higher ratio of flour and keep it in a stiffer format - around 55% hydration. Perhaps yours is similar? Having said that,  according to other information on TFL, overfeeding can also kill yeast cultures! I guess like other living things we all have to get used to our particular starters!

I wouldn't give up on it though. This page by Brian Dixon for reviving a starter may offer some encouragement as he reckons that most starters can be saved, including those that sound far worse than what you describe.

Best of luck - hope you soon return to happy baking,  Daisy_A

tsmos's picture

what may have happened to your starter is that the yeast / bacteria balance was not properly achieved - and bacteria took over killing off the yeast.

A healthy starter contains a balanced echosystem, which is vulnerable in it's first weeks (or months) and can be compromised if exposed to bacteria or other contaminants in your kitchen.


Try again, keep it clean and control the starter's environment, or get an established mature strter to work with.


Good luck!

djbrasier's picture

Thank you all for such quick and helpful replies.  I had thought to do room temperature, daily feedings because, well, that's what the pros do, but it makes sense that that isn't enough food for my yeast.

tsmos, I've been keeping the starter in a loosely sealed container which was cleaned in a dishwasher before use.  I don't sterlize the water or the flour before I put it in.  Should I be sterilizing things more?



tsmos's picture

I do not believe that sterilizing is necessary, however, one more point to consider is that high temps (over 75F or 23C) encourages bacteria growth and discourages yeast growth.  It also depends on the specific strains of yeast and bacteria that happened to inhabit your starter.

Maintaining a starter at room temperature when not baking on a daily basis is, in my opinion, a waste.

My starters (I maintain 3) have been on a weekly schedule for decades: refresh and spend up to 10 hours (winter) or 6 hours (summer) in room temp, then back to the refrigerator overnight.  Use for baking the next morning and return the rest to the refrigerator until the next 'meal' a week later.

Other notes: you may want to use bottled spring water and stick to the same brand and type of flour until your starter is securely established.  You can purchase dried sourdough starter to make sure you have a good mix of the appropriate yeast and bacteria strains.  I have seen good results from's starter cultures (website not completed)