little help?

[jesswah]

Ok, so I've got a project I'm working on, but it's not going well. I'm having serious problems with infections (lactic, I think). pH drops from around 6 to 3.5, and fermentation stops. I'm using a dry yeast, rehydrated with a nutrient (per directions), and pitching into wort of a similar temperature. I'm using plastic siphonless fermenters w/ 3-piece airlocks. Sanitizing buckets, spigots, and airlocks with iodophor; lids and labware with an alcoho spray. Everything is allowed to thoroughly dry. I'm not sure where I'm going wrong, where the contamination is coming from... and getting frustrated :mad: Any help would be GREATLY appreciated!

[Epicatechin]

First thing, I would not let the items that you are sanitizing with iodaphor and alcohol dry before you use them (unless you are using isoproyl alcohol, then I would rinse that with the iodaphor solution before use, you don't want residual isopropyl in your beer, ethanol is ok/good).

Second thing, I wouldn't use dry yeast. The water you use to hydrate it, or the container you use, or even the yeast itself may have some LAB's in it/on it (Lactic Acid Bacteria). Not only that, but yeast viability and vitality is much lower than a live yeast slurry, and it will take longer for the population to get kicked into gear. This delay allows any infectors present to get a foothold and grow.

Good luck!

[danno]

plastic fermenters can easily scratch, harboring various nasties that can evade normal sanitation methods. also, completely take apart the spigots on the bucket, they also have nooks and crannies...

I'm looking at Northern Brewer's website, you can buy a new 6.5 gallon bucket and a spigot for under $10, it may be more cost efficient (after all, what does a ruined batch cost?) to just toss your bucket and get a new one. plus, it'll save on all the hairs you're pulling out of your head...

I think epicatechin is going a little overboard with the advice about not using dry yeast. if you boil and cool some water and use that for rehydrating, you can be fairly certain you're not getting an infection from the yeast...

one last bit of advice, go get some Star-San...

[jesswah]

They're brand new buckets! The spigots were disassembled and soaked in iodophor, attached to the buckets, then the buckets wree soaked. I'm only air-drying b/c that's what it says to do. Someone is suggesting it's carboxylic acid from dissolved carbon dioxide. I don't think so. Another is saying it smells like wine (which it doesn't... at least not to me). I am fairly certain it's LAB. :confused:

[Fast_Eddy]

Tell us about your brewing procedure.

How many infected batches?

[jesswah]

Ok, so what I'm working on isn't really beer (and I can't say exactly what it is), but still a fermentation. But the "wort" is prefab, in 5 gallon pails. I've been taking out 1 1/2 gallons and heating to boiling on the stove b/c they've been stored in a fridge and need to be ~80F. While I'm waiting for it to heat, I start the yeast rehydrating. In a clean beaker (sprayed w/ isopropanol and rinsed) I heat water to 104F, add nutrient, stir, add yeast, stir, cover with foil. [I try to make sure that everything that comes in contact with the "wort" or yeast is sanitized.] Let yeast sit for 20-30 minutes. Sanitize spigot, airlock, bucket, and lid; drain; leave to dry with lid sitting atop bucket. When the "wort" is heated: I add cold wort (~1 1/2 gal) to bucket, then the heated "wort", then top it off to 4 gallons with more cooled "wort". Pitch yeast. Wipe off rim of bucket and undersid of lid with isopropanol and seal. Pretty simple, but lots of points of possible contamintion. Everything I'm using is new, ingredients, equipment, etc. Yeast and nutrient prepared according to directions, and used in correct amounts. No aeration though.

[HogieWan]

Originally posted by jesswah
But the "wort" is prefab, in 5 gallon pails.

Sounds like your prefab wort might be infected, not to mention dicey.

[jesswah]

Not likely. This is a project for work, using stuff produced in the processing plant here.

[Edit] What procedure do people here use for sanitizing? Might give me some idea as to what might be going wrong.

[Epicatechin]

Originally posted by jesswah
...1 1/2 gallons and heating to boiling ... I add cold wort (~1 1/2 gal) to bucket, then the heated "wort", then top it off to 4 gallons with more cooled "wort".

Do I understand correctly that less than half of your 4 gallons of "wort" is boiled? If so, that could very well be your problem. Also, you mention that you add 104deg water to activate your yeast. I hope this is sterile water.

It's still hard to pin down where exactly this infection is coming from. The prefab might not be infected, as in the OP you state that the pH drops from 6 to 3.5. If it was infected it probably wouldn't be starting at 6 (assuming its an acidifying bacteria).

Are you sure its infected? While 3.5 is low, it is not that low. Michelob Ultra is 3.6, for example. Without knowing what your "wort" is, it might be difficult to know for sure what's happening.

$0.02

[jesswah]

Thanks for the input. I don't know for sure that it's infected. But since both batches have stopped at 3.5 pH, it seems like LAB since that the point at which they stop growth. That's just my best guess. I know more info would be helpful, but I can't (R&D project). It has a sour smell, but not nearly as bad as the last batch. About 1/3 of the sugars have fermented, so the plato is still pretty high. The yeast hydration water is not sterile, but it's on 50ml added to 4 gal.

[Epicatechin]

Go to your local homebrew store and buy a vial of (liquid) ale yeast: White labs #WLP001 or Wyeast #1056. If it is indeed infected, my money is on the water you activate your dry yeast with.

[Fast_Eddy]

You could make a control out of the prefab. Put 1 pt or so in a sanitized flask and air lock it. If that airlock starts to bubble then the prefab is likely contaminated.

Also make a batch using your normal process then split it in half. Ferment half the way you have been fermenting and innoculate the other half with lysozyme. The lysozyme should take care of the lacto(and most other gram stain positives). If they come out tasting the same then it's the way it should taste OR a gram stain negative is the culprit OR something else.