How to avoid wild yeasts

I believe I have been having wild yeasts in my recent brews. They have been pretty lacking in flavor and have a "plastic-like" taste. I brewed up a pale with 35 ibu's and you could hardly notice the hop flavor at all. So, the question is how do I avoid them? I know they can be on the grains themselves and in the dust. Here's my problem. I have to dump my grain, boil, and rack into the primary, all in my kitchen. It's too cold to brew outside. So, how can I keep those little bastards out of my wort?

Are you sure your flavor issues are coming from wild yeasts? I have done PM recipes all in my kitchen and haven't had any problems.

Are you noticing any sort of visible activity from wild yeast? A wild yeast strain should continue to eat at sugars that your brewer's yeast will leave alone, so is your FG continually falling? Try reading your SG from a bottle and see if it is significantly lower than your reading when you initially bottled it. That would indicate some sort of wild yeast eating away at your remaining sugars.

I don't know about that, but I've all but eliminated almost everything else I can think of. I don't believe the problems I'm having are related to sanitation. Sanitation is good, fermentation temps are good (65), processes are all the same. The descriptions I've found that best describe what I'm tasting is attributed to wild yeast. It tastes kind of like plastic and everything else that you should taste is very muted. The last beer I made the hops were barely noticeable but it had a definite plastic taste.

I brew in a dusty ass garage and have never had the tastes you've described.
I'd be willing to bet it's something else, unless your open fermenting.



Have a look at some of these threads.
https://www.homebrewtalk.com/gtsear...a&cof=FORID:11&q=plastic+taste&sa=Search#1440

Are you using chlorine at all in your sanitation? I'm guessing these are AG or PM recipes?

Wild yeast, I believe, will actually form it's own thin krausen type of thing (I'm sure someone else knows the actual name for it). It should be visible in your fermenter/bottles. Since the yeast will consume your other sugars, you'll also end up with a sour or dry flavor.

Plastic taste can be from chlorine solution, either in your tap water or from using bleach for cleaning. I had this problem on one of my brews, since I didn't rinse my bottles out well enough after a chlorine bath. It could also overcome the hop flavor, I suppose. I just think that if you had a wild yeast infection it would be more noticeable.

I have had a recurring wild yeast infection, and it was nasty to get rid of. My beers were all very thin and had that plasticy, almost a 'burnt electrical' smell/taste to them.

One distinguishing feature will be over-carbonation. Do you bottle? If so, you should be detecting it there right away (left long enough, you will probably get gusher bottles following a wild yeast infection).

As previously mentioned, you might also see some evidence of yeast activity in the bottle, including a small 'krausen' ring at the neck, and 'sediment' stuck to the bottle walls.

It looks a lot like what this guy experienced (although it is hard to say what caused it in his case):

https://www.homebrewtalk.com/f39/my-beer-infected-96355/

In my case, I had multiple spoiled batches in a row until I replaced all the plastic in my brewery. Plastic fermenters and tubing are the really obvious ones. One little microscopic scratch (say from a cleaning rag or sponge) is all it takes to harbour yeast spores that WON'T be killed by typical sanitation.

Anyways, I hope that is helpful (didn't mean to be alarmist!).

Same thing happened to me as happened to FlyGuy. The only way to get rid of the infection was a replacement of everything plastic in the brew house. Ultimately, I think it was coming from the bottling bucket, but after 3 spoiled batches in a row, I wasn't taking any chances and replaced all my siphons, canes, hoses, buckets, and got rid off all the old boxes I had my bottles in.

When you guys say "spoiled" what do you mean? What I 'm getting is a definitive plastic taste. Not like band aids. Like I said, I can't put my finger on it. I've never used Chlorine to clean any of my equipment. Also, I use bottled spring water for ALL my brews. Of all the infection and off flavor threads I"ve researched, none seem to describe what I've got going on. All the flavor of the beer is severely muted and it tastes like plastic. I have no idea. I don't bottle, so that's not much help. I'm going to bottle my next batch to see if I can rule out contamination from the keg and lines.

Did you keep good notes on the gravity of the beer going into the keg? If so, take a sample again, let all the carbonation de-gas, and take another gravity reading. If you see a substantial drop, I would suspect a yeast infection. They can tear through all sorts of sugars that brewer's yeast can't ferment, and you should see that the batch slowly continues to attenuate.

Keeping the beer cold slows the yeast down, so if the beer is still drinkable, I would be tempted to keep it cold and consume it right away. You might also bottle a couple/few bottles, put them in a warm spot, and then check their gravity after a couple of weeks. If the gravity has dropped in that time, you will know something is amiss. If they gush, you will know that they are infected. They should also taste more and more like plastic as you let them sit.

So once I determine that I am having a wild yeast problem, how do I prevent it?

I had to dispose of all my plastic equipment (fermentation buckets and hoses are the key ones) and replace them before I got rid of mine. I ruined 4 batches of beer in a row before I did this. If I had just replaced everything right away, as a fellow brewer suggested to me, it would have been a lot cheaper in the long run.

I had a strange off taste in my beer, and I suppose you could call it a plastic taste. My problem was chlorine/chloramine in my water, and it was creating chlorophenolic compounds which give a harsh flavor that never fades over time. I even run a carbon block filter in all of my water, but for some reason I still got the taste. To test if this might be your problem, add 1/2 campden tablet(crushed) per 10 gallons of brewing water. The campden combines with the chlorine/chloramines and creates gaseous sulfur dioxide which gasses out of the water. This removes all chlorine and chloramines from your water.

After using campden tabs, ever single one of my brews since has come out perfectly clean with no hint of that flavor. If you feel your sanitation is good, you filter your water, and nothing else has changed in your brewing process try out some campden.

BWRIGHT said:

So once I determine that I am having a wild yeast problem, how do I prevent it?

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If you are sure you are sanitizing your equipment thoroughly, and if you are using plastic buckets and haven't taken swabs and plated them you aren't sure, then all you can do is minimize exposure to ambient air during transfer.

Taken swabs and plated them? That's rich. I don't work for the CDC, I just think it's a wild yeast because I can't match the taste to anything else. I use 100% bottled spring water for all of my brews as well. I've replaced all my tubing. I guess I should replace my bucket too.

BWRIGHT said:

Taken swabs and plated them? That's rich. I don't work for the CDC, I just think it's a wild yeast because I can't match the taste to anything else. I use 100% bottled spring water for all of my brews as well. I've replaced all my tubing. I guess I should replace my bucket too.

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I think mine came from the bucket. And if you have used those hoses and things with that bucket, you may have re-contaminated them.

Well, when I say bucket, I only mean that I use an Ale Pail to hold all of my equipment in Iodophor as I'm brewing. I don't ferment in buckets.

Mine was the bottling bucket. But if everything is in a sanitizer solution while it's in the bucket, I doubt any bugs are going to take the swim over to your equipment.

Wouldn't a nice soak in acidified (vinegar) bleach solution kill everything if given a long enough contact time? Even if your plastic is harboring nasties in a scratch, a 20-30min soak in solution of 1oz bleach:1oz vinegar/gal should kill everything dead.

GNBrews said:

Wouldn't a nice soak in acidified (vinegar) bleach solution kill everything if given a long enough contact time? Even if your plastic is harboring nasties in a scratch, a 20-30min soak in solution of 1oz bleach:1oz vinegar/gal should kill everything dead.

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Nope, unfortunately not. The micro-biologists say it doesn't work, and I even tried to prove them wrong (I failed, then finally tossed my plastic).

I did save my autosiphon and beer thief by heat sanitizing them in my dishwasher (has a high-temp, sanitizing cycle that works very well). The pail wouldn't fit, though.

What's the reasoning behind the ineffectiveness? If bleach/vinegar solutions in that same concentration are recommended by the CDC for killing anthrax... My bet is that the contamination was coming in from another vector that you subsequently remedied after the equipment was replaced.

GNBrews said:

What's the reasoning behind the ineffectiveness? If bleach/vinegar solutions in that same concentration are recommended by the CDC for killing anthrax... My bet is that the contamination was coming in from another vector that you subsequently remedied after the equipment was replaced.

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If the infection is living in a scratch that the solution can't get into, then it doesn't matter how deadly the solution is, it won't do anything because it can't reach the problem area.

me remembers mixing chlorine with muriatic acid while acid washing a pool.
me remembers emergency room, but not the ambulance ride.
me does not mix acid with chlorine.
wtf are you recommending here?


the bucket is like 7 bucks. go get a new one.
chlorine gas kills people. WWI, anyone hear of it?

ok, maybe vinegar is not as strong, but it cannot be good for the lungs.

this thread was enlightening however. im worried about my buckets. my haus pale ale tastes like dog**** (no, no personal experience with that taste, just slang for poor tasting).

muriatic acid(HCL) is a gas, Smells yummy

nosmatt said:

me remembers mixing chlorine with muriatic acid while acid washing a pool.
me remembers emergency room, but not the ambulance ride.
me does not mix acid with chlorine.
wtf are you recommending here?


the bucket is like 7 bucks. go get a new one.
chlorine gas kills people. WWI, anyone hear of it?

ok, maybe vinegar is not as strong, but it cannot be good for the lungs.

Click to expand...

You sir are a moron.

Vinegar increases killing power of bleach

Basic Brewing Radio podcast with Charlie Talley from Five Star Chemicals (Star San) talking about using bleach in brewing

Watching with amusement.

Ib4tl67890

I finally realized my keg fittings were infected. Now I disassemble them and BOIL fittings and lids. Lye and Iodophor for the rest of the keg, agitated with a one-use cotton rag on a stick, turned by an electric drill.

Pretty sure I've had the same issue. Gone through the same process as you trying to pinpoint it - I've never had an infection in fermentation, nearly all of my batches (over 8 months of AG brewing) have tasted excellent (imo) - or at least what I was after or expected - out of the fermenter. But once in the bottle, they develop the same specific off flavour. Sometimes they stay good for the first week then go, other times it presents right away. I've used spring water, tap water, distilled water - same problem develops. It's not DMS, diacetyl, band aid, metallic, phenolic, esters, green apple or any of the other most noticeable classics. I upped my bottle/gear cleaning regimen for a recent bottling batch (again which tasted great out of the fermenter), replaced main tubing and had a relatively new siphon, and I bottled it in a different location (helping pinpoint if my kitchen is just a mess and the culprit) - all to have that same flavour still develop. I was told it might be oxidation/cardboard - and other than cardboard being difficult to actually taste - it's even more difficult not exposing homebrew to air. I think I'm clean/sanitize decently, and am as quick and gentle with transfers as possible - but can't say.

All to say I feel your pain. As others have mentioned, I'd heard wild yeast presents as overcarbonation - which IS something I've had consistently. So this could be it, but I have trouble knowing where wild yeast is getting in - other than through air into my bottling bucket. Certainly possible, but if it was that easy I'd assume every record in the annals of homebrewing would be plastered with people talking about it - something I have NOT found or seen. So, I have two batches close to finishing and do not know whether to buy kegs and throw bottling to the wolves, or try yet again...

Do let me know if you have any breakthroughs; I'll do the same.