Starter smells like plastic
First time attempting to make a sourdough starter without inoculation, and it smells like plastic, with perhaps a slight hint of gasoline. I've seen many mentions of what I would call normal fermentation odors--alcohol, bananas, vinegar, acetone--and smells that indicate spoilage (garbage, vomit), but no good match comes up when I google "sourdough plastic odor".
The only plastic the ingredients come in contact with is the container I use to weigh the flour. The flour is the tail end of a large (5 lbs?) bag of all-purpose flour I purchased a couple years ago and stayed in the paper sack it came in until I needed to refill the plastic container I keep in the kitchen for short-term use.
The smell emerged on day 3, and has intensified but not changed character through day 5. I could imagine calling it a banana smell, but that would be a stretch. It's just not quite like anything I've seen mentioned anywhere. Perhaps faintly banana-like, but also like plastic and a little like gasoline or some other solvent.
Anyone have any ideas what this could be?
Mean spoilage. In fact bad smells at this stage are part of the process. With careful maintenence you should still produce a viable starter and it'll smell nicer.
What have you done so far and is it bubbling?
Thanks for replying, Lechem. I've been "experimenting" with various kinds of fermentation, including "natural", so I'm familiar with the "bad" smells that actually are good. But this is my first time making sourdough from scratch, so the smell of the flour alone is "different" (compared to, say, sauerkraut or cream for cultured butter). Last night I read Debra's article about how she developed the "pineapple" method, and her descriptions of the different odors at different times and at different pH explained a lot.
I started out mixing 4 oz of flour and 4 oz of water in a large mason jar. I covered it with a tea towel and set it on top of my computer under my desk, where it's about 70 degrees (F). On Day 2 it already looked like it was beginning to produce gas, but not enough to make bubbles. I added 3 oz of flour and an equal amount of water, and on Day 3 it had risen and was getting spongy.
I added 2 oz of flour and 2 oz of water, and after another 24 hours, it had doubled in size and was very spongy. That's when I noticed the plastic-with-a-hint-of-gasoline smell. At this point the volume of the "sponge" (I know it's not the same as a sponge for preparing bread dough, thus the quotes) filled the entire jar, so I stirred it well and spooned out half, to make room for another 3 oz of flour and 3 oz of water.
Now, after another 24 hours, I'm beginning to get the characteristic sourness emerging through the "plastic" odor--so I think it's going to be alright.
At the beginning are from bad bacteria, which we do not want, but is a necessary step to get through before the good bacteria and yeasts prevail. So bad they are but doesn't mean your starter has failed. When your starter matures the PH level will drop, become acidic, kill off the bad bacteria making a good environment for the LAB and yeasts to thrive. Sometimes after this initial bubbling up (which looks like a healthy starter but it isn't at this stage) it goes quiet after it's fed again. Things are still happening. Once it bubbles up again, begins to smell good and becomes more predictable then your starter is ready albeit still a bit young (and will mature in flavour over the next 6 weeks). What the pineapple juice does is create that good environment speeding things up giving it a boost.
I don't know about plastic, but the small "gasoline" smell means there is activity. Try stirring it more often. What procedure are you using? What physical observations have you seen? If you have any dark rye (medium would be ok, but dark preferred), adding a little to your starter will give it a kickstart if you want.
I think stirring more is a good idea, Maverick. See my reply to the first comment for my "procedure". Since I feed it just once every 24 hours, it separates into a base layer with no bubbles, a thin layer of liquid, and the rest (about 2/3-3/4 of the volume) is the spongy mixture. Stirring them all together again certainly would mix the micro-organisms in the different layers and redistribute everything evenly again...and it would expose the mixture to more oxygen.
Thanks for the tip about dark rye flour. I noticed that the folks here tend to use a lot of whole-grain wheat flour, and mix in at least some rye. I have now split the starter into two batches, and I'll get some rye flour tomorrow and add it to one of the batches...it'll make my little experiment more interesting!
More info would be helpful since there are so many different ways of doing this. It sounds like a start (no pun intended) but it sounds like you have a ways to go.
What is the ambient temp in the place you are keeping this starter? This can have a big influence. Yeast loves about 80F. LABs loves a bit cooler.
Taste your starter- is it acidic at all? If it isn't, you can use some pineapple juice to help acidify it quickly to prevent harmful beasties from growing. Alternatively, hold it a little cooler to get the LABS going as their role is to acidify a starter.
Is there any bubbling after a feed?
Is there any hootch formation?
How often are you feeding? Any ratios of flour to starter, if you measure? Nice to know but not required.
How does it behave when you feed it? A new starter will go through a phase of wild activity that will be the LABs-not yeast. It should get to a less wild, more consistent rise after that and actually smell a bit beer-y or yeasty.
What consistency do you keep it at? Pancake batter? Clay? If you measure- what percent hydration?
Keep going and stir often.
Thanks, clazar--lots of good questions...
My method, if I can call it that, is as simple as it gets--just all-purpose wheat flour (no whole wheat) and an equal amount of water (by weight). I fed it with some of the same mixture every 24 hours, adding a little less each day. Now that it's showing tons of activity, I'm spooning off half and replacing it with the same 1:1 mixture (always measured by weight, not volume).
It didn't taste sour last night, but it's starting to smell a little sour tonight (I haven't tasted it again yet). I've had it at a temperature of about 70 degrees, so it sounds like I ought to find a warmer place. No evidence of yeast yet, but there definitely lots of bacteria, and now perhaps the lactobacilli are starting to take hold.
Yes, there is some hooch. I've been feeding every 24 hours, and it definitely is still in the wild-activity stage. The consistency is like pancake batter, although after Day 2 it was getting a little rubbery (gluten) and now has *lots* of gluten--when I rinse the starter I discard, what's left has a cheesy consistency.
I think all of this is okay, considering that the "plastic" odor is weakening and some sourness is detectable. As you suggested, I'll keep it going and stir more often!
At the beginning of a starter formation, it is easier and less wasteful to work with a small amount so you do not need to discard. When you discard at this stage, you are getting rid of half of your yeast population. Try not to do that until you have well established the yeast growth. So stir up your starter and just take a generous tablespoon out to work with or put it all your starter into a larger jar for now.
If hootch is forming on top, there is yeast present and it is hungry. Feed it twice a day and put it into a warmer location. The top of the refrig is usually ideal as the heat rises off the back of the coils and forms a little micro-warm climate there. The microwave with the door open so the light is on is my next favorite place.
Cheesy-looking texture is ok. Cheesy smell is not. That is a not-so-nice contaminant that is difficult to get rid of.
You are so close. Warm-stir-feed.