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Author Topic: Lactic activity... or spontaneous fermentation/infection  (Read 3333 times)

Offline Michael

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Lactic activity... or spontaneous fermentation/infection
« on: August 15, 2017, 05:06:15 pm »
So, I boiled a wort to sour at 12 Plato, no hops, lactic acid addition to drive ph down to 4.2, and inoculated with WLP677 lacto at~100F on Saturday.

Monitoring has shown zero change up until this morning.  That is a little under 3 days.  I assumed the vial may have been compromised with heat during handling and maybe was lost or weak enough to need more time despite being something I understood should be able to drop the ph to 3.5 in a few days tops.

Getting home this evening I found a lot of activity and immediately took a sample to see what was happening.  I found that the ph is still 4.2 and the gravity dropped to 11 Plato.

Sadly, it seems that I have either infected it with wild yeast or whatever impurities that were in the 677 vial.

My plan was to drop ph, reboil, hop, and dose Cali yeast in the primary and then apricot purée in the secondary.   Looks like that plan is out the window now.  Any thoughts?




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Offline Michael

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Re: Lactic activity... or spontaneous fermentation/infection
« Reply #1 on: August 15, 2017, 07:54:49 pm »
After further digging a foamy krausen is normal.  I just got panicky from the dropped gravity and same ph.  However, the ph is now dropping! I will check again in the AM since at this rate it may be ready to draw off and boil then.


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Offline reverseapachemaster

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Re: Lactic activity... or spontaneous fermentation/infection
« Reply #2 on: August 16, 2017, 09:43:07 am »
White Labs is notorious for having yeast in their lactobacillus strain. Lactobacillus does not produce krausen. That's definitely yeast and likely yeast from WL. Most likely nothing you did wrong here.
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Offline Michael

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Re: Lactic activity... or spontaneous fermentation/infection
« Reply #3 on: August 16, 2017, 01:13:35 pm »
White Labs is notorious for having yeast in their lactobacillus strain. Lactobacillus does not produce krausen. That's definitely yeast and likely yeast from WL. Most likely nothing you did wrong here.

Yeah, I am confused as all hell.  Hit 3.6 ph just fine but the gravity fell to 7.5 Plato.  I went ahead with the 15 minute reboil and hop addition to halt the lacto.  I probably boiled off all of any alcohols from that fermentation.  See how it goes over the next few days and then rack and add purée.

It is pretty funky smelling already so it should prove interesting.


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Offline Pricelessbrewing

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Re: Lactic activity... or spontaneous fermentation/infection
« Reply #4 on: August 17, 2017, 10:32:51 am »
http://www.milkthefunk.com/wiki/Lactobacillus

Like the rest of WLP lacto strains, it's a super low cell count (meaning slower souring), and combined with the well knock issues at white labs for their lacto strains, it is not well suited to kettle souring.

Like reverseapachemaster said above, lacto does not produce krausen or ferment more than 1-3 gravity points. If you got more of a SG drop than 3 gravity points, you have yeast in there.

I highly recommend omega yeast labs, the yeast bays lacto blends, goodbelly probiotic yogurty drink thing, or a lacto probiotic pill that contains pure cultures of l. plantarum for kettle souring at 90-95F tops.


Offline Michael

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Re: Lactic activity... or spontaneous fermentation/infection
« Reply #5 on: August 17, 2017, 10:39:32 am »
http://www.milkthefunk.com/wiki/Lactobacillus

Like the rest of WLP lacto strains, it's a super low cell count (meaning slower souring), and combined with the well knock issues at white labs for their lacto strains, it is not well suited to kettle souring.

Like reverseapachemaster said above, lacto does not produce krausen or ferment more than 1-3 gravity points. If you got more of a SG drop than 3 gravity points, you have yeast in there.

I highly recommend omega yeast labs, the yeast bays lacto blends, goodbelly probiotic yogurty drink thing, or a lacto probiotic pill that contains pure cultures of l. plantarum for kettle souring at 90-95F tops.

I will definitely go that route next go round.  This did get a surprising ph drop though.  Too bad I panicked and didn’t just let it go.  I am considering hydrating and heating some dme and adding it in to the primary that has just started taking off to get back closer to my original sg.


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