Lacto Starter Concern

[rlonardo]

So I decided recently to brew my first sour, a Berliner Weisse. This past Wednesday I went and made myself a lacto starter using hot water and some crushed grain. Put that mixture into a mason jar and left it covered with aluminum foil in a warm area (80-90).

The first couple of days it smelled exactly as I thought it would, like soured milk. However, when I got home today and gave it a whiff the smell had completely changed. It is still sour, but smells more solvency and kind of burns the nostril.

Against my better judgement, I decided I would taste it. It tastes sour and grainy, just as I would imagine it should!

Did my lacto lose? Am I just smelling a higher concentration of acid (acetic perhaps?). Thoughts?


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[dantheman13]

Sounds like ethyl acetate (acetone), probably due to wild yeast that was on the grains fermenting at that high temperature. I would use the starter and see what happens, but don't ferment the beer with that starter at that high temperature. Hopefully at a lower fermentation temperature the acetone doesn't come through.

 

[rlonardo]

Well, a few days later and the smell has definitely mellowed out a bit. It has more of a lemony scent to it. The taste hasn't changed much. Still very sour, nothing in there that makes me gag, which is good I suppose.

I got a little nervous so I made a second starter Saturday night (screw it, I used $0.50 worth of grain). Today the smell is basically the same as the first, and the flavor is sour but not quite as strong as the original.

I plan on brewing this on Wednesday after work, so I'll plan to pitch the original then.