Starter has become weak and unresponsive.
After pulling out some terrible, barely-risen, tight-crumbed loaves out of my oven the past couple of weeks I had to do some troubleshooting and eventually managed to figure out that my starter is misbehaving. I am not really sure why. The past few months I've kept it at 125% hydration and was feeding it twice a day at a ratio of 1:5:4. Loaves were coming out fine. But the last two weeks it hasn't been working well. Nothing had changed in my feeding schedule or ratio; the only thing is I put it in the fridge for a couple of days when I wasn't baking, but I did refresh it a few times before using it in dough.
I'm wondering if I may have misinterpreted the readiness of my starter all this time, and was using it when it was underripe or overripe. Because it's a high hydration you can't judge by how much it's risen, so I went by smell and bubbles. I think 1:5:4 was possibly not enough as it did develop a little hooch, but I didn't increase the ratio because I'm cheap and wanted to conserve flour (also the breads were coming out fine so it wasn't an issue). Since the problems started (and by that I mean the dough wasn't doubling unless I added some yeast) I decided to up the feed ratio to 1:7.5:6 - the result was the same, still a little hooch, no rising.
At this point I figured I'll do some first aid, reduced hydration to 100% so I can better judge what's happening, and fed it 1:1:1. That was 16:00 yesterday. By 23:00 it had risen by about 30%. This morning it stayed at the same level and there's no indication that it has risen and fallen. Just now I fed it at 1:0.5:0.5 to give it a serious boost and we'll see what happens.
Anyway, the point is, why did this happen? Did the yeast population dilute because of too frequent / infrequent feedings? Did the hydration level / pH levels have anything to do with it? Has the change in temeperature that has happened over the last few weeks messed up my starter somehow? Did the volcanic ash cloud work some voodoo on it? It happened pretty suddenly - one week my breads were fine, the next they were not. Literally nothing changed inbetween except for that short fridge time, and that really shouldn't have such a negative impact on a culture, especially since I did refresh it twice before even using it in bread.
Anyone have any ideas? I know higher hydration cultures ferment quicker which is why I think maybe I was underfeeding all this time, gradually killing the yeast populations. But with regards to the hooch, it was never a large amount at all, just a very thin layer on top, and sometimes it would appear even one hour after feeding - surely not enough time for a culture at room temperature (~19C) to go through a 1:5:4 feed? Or was I misled by this "hooch" (or whatever it was) to think I was underfeeding, and really 1:5:4 was way too much and I was in fact overfeeding to the point where the yeast have been seriously diluted? But if that's the case what is that thin layer of liquid if not a sign of underfeeding? And how can I consistently and reliably judge the ripeness of a liquid culture? "Bubbly" it certainly is, does it have to go all the way to "frothy"?
In my opinion you weren't overfeeding it, but you were seriously diluting the yeasts. With that rate you should wait a lot of time to restore the yeasts density.
You can still keep the hydratation at 125% and feed your starter without diluting it too much (1:1.25:1 such as 40:50:40) but does it take any advantage? There's a long thread here on TFL about starters with very high hydratation where Debra Wink explains pros and cons of such a method.
I prefer to feed the starter with 1:1:1 and get a visual indication of its health: if it doesn't grow well in decent times it won't grow a good bread/cake.
I originally went to 125% because I was baking through Hamelman's "Bread" and for ease of use decided to keep mine at the same hydration as he does. I then decided to stick with it just because it's so easy to mix, but I can go down to 100% yeah, it's not a big difference.
What confuses me is why I had that layer of liquid at the top. It also did smell somewhat alcoholish when I fed it at 1:2.5:2 which is why I assumed it was underfed, so I upped it to 1:5:4.
Right now, four hours after I fed it at 1:0.5:0.5, it's already got a thin layer of liquid/hooch on top but has not risen at all. If my camera wasn't awful I'd take a picture.
Maybe Hamelman uses that hydratation because he uses high gluten flour? Flours like that absorb so much water that at 125% the consistence is just right, maybe just like your at 100%. I guess you are using a weaker flour, in which case I'd use less water, until it stops hooching.
If it smells alchoolic it's rich in yeasts but probably it's growing fewer lactobacilli than it should... maybe.
I keep my starter at 100% hydration, and there's never any doubt when it's active. It easily doubles and becomes light and liquid after an overnight fermentation. After only 4 hours, it has a few 'bumps' on the surface, and hasn't risen much, but it doesn't have any liquid, although the texture will have changed to a looser feel.
I've been told that the hooch is a sign that the yeast are dying, usually due to being underfed. I suspect your starter is seriously weak. It should easily double. Your refreshment ratio seems OK (about 1:10 old flour to new flour) although if I'm being obsessive about it I prefer 1:5. The difference between 1:5 and 1:10 is not a big one from the yeast's perspective. I would try adding some rye to your refreshment, to see if the yeast respond to better nutrition. Yeast need air and somewhat warm temperatures. Could either of those be a contributing factor?
I also think you should try feeding it with organic rye flour/organic ww flour/and an organic AP flour... That should revive it... The organic stuff has more yeasties... I keep only a 200-300g of starter in the fridge. I usually feed it anywhere from 50-100g of flour each time. I will refresh and leave it out on the counter for about 4 hrs and then fridge it until I'm ready to use it...
Also what you can do is start feeding your starter at 100% hydration to get the yeasties going, and then bring it down to a 60% hydration storage starter that you can keep in your fridge and feed it once a week or as necessary...
I fed it with rye last night. Right now it hasn't risen at all, but it smells very sweet and sour. There is at least something positive going on there... I'm out of rye but do have some WW so I'll keep feeding at 1:0.5:0.5 until it starts doubling convincingly in 12 hours.
I don't think temperature is a problem because it was going fine since November. I was actually surprised that it's become so weak right when the weather became warmer.
I did have it at 60% for a while but decided that it's too much work to feed (I bake 3-4 times a week so I keep it outside of the fridge and feed twice a day), that's why 125% was so great, you could do it in 2 minutes without any mess.
Thanks for the help guys.
and that is 66°F Much too cold for a weak starter. Get it a bit warmer, up to 23° for a few days and see what happens. It could be that you have other acid producing beasties and few yeasties. (Reducing the feeds to less than the starter is the same as waiting 24 hours for feeds and you were still noticing a sour going on so there is not much dilution of acids in the starter. Flour reduces the acid so I would not reduce the flour!)
Go to the 1:1:1 with whatever flour you have and get the starter into a warmer spot to promote the yeasts and feed them using warm water. They like warmth! Park a thermometer next to them to keep check. Important to still stay on a 12 hr schedule to dilute the acid forming in the starter if that is indeed what is happening. Taste it to see if it is sour after 12 hours standing; if not, let it stand longer but not over 24 hours. As yeasts show an increase, increase the flour amounts to twice daily feeds. Then slowly twice a day until you are back to the 2:5:4 ratio. Start with 1:1:1 then 1:1:2 then 2:5:4 and finally after a day at each, stay there. Go back to 1:5:4 when the room temperature rises to 23°C.
I think the starter got too yeast diluted as the temperature dropped, maybe just over a few days, then it just couldn't keep up with the feeding schedule.
Once it is working again and as long as it is cool, increase the amount of starter to refresh and feed every 12 hours or feed as was the routine only every 24 hours. You do have to be flexible. I tend not to be so exact and make small adjustments with the daily temperature as I feed. If the fermenting seems to be slow, less flour and more warmth; seems to ferment faster, more flour or cooler temperature. Spring and Autumn can be a roller coaster ride for the starter beasts.
Mini
I really need to get a thermometer, huh. I've been postponing it for a long time. Okay, so 1:1:1 every 12 hours if it's already sour or 24 hours if it's not. But should I discard anything during the feeds? If it's sour after 12 hours and I discard and feed it, would I not just be diluting the yeast population grown in the past 12 hours again? Or is it a case of taking a step backwards in order to be able to move forward again (i.e. diluting the yeasts but at the same time reducing acidity so that they can come back in force)?
Any tips on recognizing ripeness in 125% hydration starters? If it's 100% I can judge just by volume, but at 125% it gets tricky. Does it have to get really frothy?
In any case, after feeding it with whole wheat this morning it has grown 50% in 12 hours, so the advice I'm getting here is already helping. Thanks again.