Yeast Starter tastes Vinegary

[Smiddylad]

Hi
Does anyone know why a yeast starter should taste vinegary and should it be dumped. I have made a starter of WLP002, I made it using a stir plate. I always taste my starters to make sure it is okay and this one has a distinct vinegar taste. Should I err on the side of caution and dump it or should it be okay?

Neil

 

[Dronfieldbrewer]

Unless you work for Sarsans vinegars I would dump it

 

[Jimmy321]

The starter will taste nothing like a brew or the yeast you started with.

I made a starter with WLP800 (Bohemian Pilsner) on a stir plate which tasted like sour cider and it turned out excellent, if fact I used it 3 times and each time the spent wort tasted sour but the second brew was again excellent and the third is still lagering.

 

[Jimmy321]

Taken from yeast labs Q&A section, it's from the vial but as I said above mine stated sour with a 2 step starter.

Q, I have just tasted some of my 005 yeast out of the vial, and it tastes sour. I just wanted to know if this is normal.

A, People are often surprised by the way the yeast smells or tastes out of the vial; it is hard to judge since it is a concentrated yeast slurry. It is not going to taste like beer. The pH is also lower, so the higher acidic flavor can taste sour. You really cannot tell purity by smell or taste, although it is not a bad practice to try and become familiar with what is normal. The only way to know purity is to plate the yeast on to special media, which is what we do on all of the lots at White Labs.

 

[Smiddylad]

Thats what it tastes like cider, there is no phenolics so there isn't a wild yeast infection. So do you reckon it should be okay?

 

[Jimmy321]

Going by my own experience and the Q&A I would decant the spent wort and pitch it but no blames of it goes wrong

 

[Smiddylad]

I think I will and if it goes bad I'll know next time

 

[Jimmy321]

Cool, remember to bump the thread when it's ready so we know for the future.

 

[Smiddylad]

Yeah have to give this thread closure.

 

[Smiddylad]

I had a taste of the fermenting beer last night and so far all is good. No hint of vinegar or cider. Will know for sure once the fermentation is complete next week. But looking good so far. :)

 

[Jimmy321]

Cool, I will be making a starter with WLP029 to split and pitch for brewing next weekend I will have a taste of the spent wort before pitching. It's worth knowing as not to discard good yeast in the future.

 

[Smiddylad]

Hi All
Just to give closure to this thread. I packaged my beer last night and had a good taste of the finished beer. No off flavours detected, in fact perfect fermentation. I can only ascertain that the cidery flavour stemmed from the high levels of oxygen in the starter from the stir plate. I’m a big advocate of tasting starter before pitching them in beer just too make sure there are no off flavours such as phenolics as that has caught me out a few times. However that said, it’s also good to question it too. I was about to dump my starter, so thanks all for the advice, it’s helped save my beer :)

Neil

 

[Hopshed]

Hi - glad your beer went well. Starters frequently go like vinegar after a while, my understanding is that its the alcohol slowly oxidising to acetic acid.