The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Grassy Smell During Poolish Fermentation

dhaban's picture
dhaban

Grassy Smell During Poolish Fermentation

So I have a good one for you all.

Since I started using my newly founded sourdough starter (which is nicely active ... doubles within 2-3 hours after being fed) I've noticed a rather strong grassy smell when I lift the cover off of my stainless steel KitchenAid bowl after my initial fermentation of the poolish. I'm making a traditional sourdough using a King Arthur recipe. This recipe calls for the fed starter, flour, water and salt. I've determined that the smell is off-gassing from the fermentation process as the finished loaves taste quite good. I have used two different types of flour and this off gas smell exists after each type of flour ... so it's not a result of the flour. I use filtered water from my Berkey (no chlorine or fluoride). I use kosher salt as well. So, not much here to go wrong ... very basic ingredients. The interesting thing is that I don't get this grassy off-gassing when I remove the lid on my starter culture. It smells fine (sour and slightly sweet). So, this grassy smell is occurring during the fermentation of the poolish. I'm considering trying my city's tap water next to make sure there isn't something lingering in my filtered water. I'm assuming the grassy off-gassing is a result of the yeast's diet. Now, what could they be eating to produce this smell?

Folks, do you have any ideas?

hreik's picture
hreik

fermenting in the same stainless steel bowl?

dhaban's picture
dhaban

@hreik   Yes, I mix the water, initial flour amount and starter into my 6qt KitchenAid stainless steel bowl. I beat it for a minute by hand, cover it and allow it to ferment at room temp for around four hours. It then goes into the refrigerator overnight for around 12 hours. I then allow it to warm up, add the remaining flour and knead to form a smooth dough. I can detect the grassy off-gassing at all stages of the process on the pre-ferment and on the doubling stage before the dough is divided and placed into the baskets to rise.

hreik's picture
hreik

But I'd use bottled spring water.  just try it once and you'll know that something is off in your filter.

dhaban's picture
dhaban

Ok. So for any of you that use the KitchenAid 6 qt bowl with KitchenAid plastic lids, the gas from the fermentation appears to react with the plastic in the lids. I have just made two separate batches of poolish without the grassy odor in either batch after using the same water and flour. You learn something new every day I suppose.