View Full Version : "infected smell" smells like...???

08-11-2005, 10:27 PM
I was nosing around on here and trying to find what exactly an infected batch smells like.. ie. what smells/type of smells say "this batch is clearly infected."? I have read the list of "typical" off-smells gets posted on here routinely, so I know the diacetyl, acetyl, and so ons. So would someone who knows, please tell me/us what an infected batch smells like??

I ask this as I am somewhat concerned about two of my batches in progress. One of which is the jasmine flowered OB honey mead, while the other is my original batch of red tea mead.
The jasmine flowered one has the worst smell coming out of the airlock. Yes, there is a little jasmine smell, and a little of the OB honey must. But the part that scares me is that there is a really nasty, but somewhat elusive smell there too. The only way I can think to discribe this smell is that it smells vaguely like the "high esters" in vomit.. Definately not what I wanted to smell coming out of my meads. Such an odd and nasty smell makes me wonder about infection. With a big goopy mass of jasmine flowers floating near the surface of the mead, its tough to tell if there is anything funky on or near the surface. I had this batch airlocked and it still is fermenting well, airlock bubbling happily along. I swirl it once a day to put the flowers back under the surface, since the CO2 pushes them up a little bit. When I swirl it, I get a huge rush of CO2 coming out of solution, but don't see any funky strings or other critters that shouldn't be there. I replaced the vodka in my airlock since it seemed to have gotten a little of the must up in it, but the vodka removed from the airlock smelled and tasted ok. (besides the vodka part)
The original red tea batch has an off odor to it as well, though definately a lot less concerning than the other one. This batch has an off odor that reminds me of a field of rape seed plants. The real "high" smell that is kinda unpleasant and vaguely sweet at the same time. Kinda like the sweetness of benzene but the oilyness of warm crayons/wax and a hint of mustyness from dirty socks. I really can't describe this smell any better, unfortunately. The funny thing is that this batch seriously got heat bit, and smelled like bubble gum afterwords due to all the acetylaldehyde mixing with the red tea. This might be the chemical progression of those two, but I don't know. The batch appears ok, with no visible critters. Though it is in a green glass bottle and any tough-to-see "hazy critters" would be almost invisible. Fermentation is slowing way down, but since the SG was 1.042 on 6/25 I would imagine the sugar content is pretty low.
So do either of these smells smell like infected batches? Any thoughts, comments, or suggestions??

08-11-2005, 10:51 PM

What you're describing sounds like brett (brettanomyces) influenced mead to me.

I'll PM you some additional information.



08-11-2005, 11:33 PM
thanks Oskaar,
I did a little checking on "brett" and I think you are probably right. Although it seems a bit odd for it to be in a mead, since most of the articles mention it as a wine/grape issue. I wonder if it might have come in on the flowers. I haven't gotten your pm yet, so I will hold off on any questions untill then.
not to sound ungrateful, but could you provide any insight into what bacterial infections of mead tend to smell like? if they have a specific smell?? Just so it gets posted on here.

08-12-2005, 12:31 AM
To me the ones that I would watch out for are:

Acteobacter, Lactobacillus - vinegary, cidery, malt vinegar smell. Acetobacter can also produce ropy jelly like strands known as ropiness.

Pediococcus - this produces diacetyl and acidic aromas and flavors.

Here's a link to John Palmer's How to Brew page that lists common off-flavors and aromas.




08-12-2005, 10:50 AM
Remember, a strong acetobacter infection is a good thing if you are trying to make vinegar. :D

Brian K
who is going to make vinegar this weekend out of a fairly bland Spanish white wine

08-12-2005, 12:56 PM
Yup, our family's mantra at wine making time was always "If you don't give me good wine, you're anchovy bait!" (Caesar dressing mixer)



08-12-2005, 10:51 PM
Well, I wish I could say that I am making vinegar, since I happen to be out. but anyhow... The one smell is seriously starting to scare me.
It really does somewhat smell like butyric acid, as it has the define vomit smell, but has a very "high/light" estery quality to it, which always accompanied the acid. I did some digging and found that while the "brett" yeasts make some nasty smells they usually smell "musty or horsey" which does not qualify. Further digging shows that butyric acid sometimes shows up in beer, but "high levels" are due to Clostridium infections.(bacterial) Another article mentioned that butyric shows up in beers called "sours" but only mentions that "micro flora" are important, mentioning pedio cocus and brettanomyces later on in the description. But I have yet to read any article that mentions what to do if you have a "brett" infection or one of the related critters. Nothing mentions if the batches were salvagable either.

so here are my thoughts:
A: Do nothing, let it do its thing unbothered untill it clears enough for me to rack off the flowers. Hopefully, if I am brave enough I will taste it and know if I should dump it or continue on.

B: The opposite extreme, finds this batch being mixed with bleach before going down the drain.

C: Hope its a brett issue, and make up a K1V starter and onces it rolling, dump it in there to make war with the "bretts". I know the K1V would completely dry out the mead, but dunno how it would deal with whats left of the flower flavors or what the hopefully bretts had done.

D: Strain out the flowers and pastuerize/boil the whole lot, then re-pitch with either EC-1118 or K1V.

So those are my thoughts for the moment. I would appreciate any comments or thoughts you all have.

08-12-2005, 11:03 PM
Could be that your flowers themselves are the problem too. Maybe they're putrefying and causing the problem?

Just a thought.

Did you get my email?



08-12-2005, 11:14 PM
Yes, I most definately did get your email and replied already, thanks. As for the flowers, I don't think its them putrifying, but honestly, can't say for sure. I was thinking that if I fished some out to check, I might be smelling the "critters" on them. Rinse them maybe? Or I was thinking of running a test of sticking some of them in a sealed jar with some water for a few days then smelling them. but perhaps I am thinking too much about all the wrong stuff..
hedgehog, the confused and lately nuerotic.

10-14-2005, 11:55 AM
Basic rule: If it smells like a sewer its infected. and it definately sounds like you've got an infected batch. I had the same problem with a batch on watermellon wine and recently a pineapple mellomel. The later I sulfited but It didn't do any good. What I learned is this: 1) Always boil your must. Makesure everything in it is DEAD, not just clinging to life in a hostile environment. 2) Always santize your equipment. 3) Make sure everything else ( Pipettes, Airlocks, and thieves) are sterilized in bleach solution and rinsed with distilled or bottled spring water.

In your case I would boil the must for fifteen minutes and add the spices just before removing the pot from the stove and placing it it the primary. This will allow the volitiles to infuse while there is still more than enough heat to kill any hitchhikers.

10-14-2005, 12:19 PM
FWIW, here are two links describing the components found in jasmine flowers/ stems: http://home.earthlink.net/~garnish/jasminelist.doc

As you can see, there are some interesting compounds present. The decomposition of some of these compounds would lead to the smells that you described. The question is whether or not the decomposition is natural, or a product of enzymes produced by contaminating organisms.


10-16-2005, 08:08 AM
What I learned is this: 1) Always boil your must. 2) Always santize your equipment. 3) Make sure everything else [is] sterilized in bleach solution While I'll not argue these steps are effective, I would point-out that boiling a mead must is absolutely NOT necessary, and will drive-off much of the honey character in your mead... ;) At least this has been my experience.

The nature of honey is that it is intrinsically biologically stable, which is why it does not ferment in the hive. Assuming one exercises sound equipment sanitation [sterilization is unnecessary, IMO] bacterial activity in a mead must can be suppressed, and no infection will result - this has been my experience over the past 10 years.

I though it would be important to point-out to those who are less experience that boiling musts is NOT necessary to prevent must infection. Of course this is only my opinion, and that of others - e.g., Ken Schramm... :)

10-16-2005, 12:20 PM
I agree with Hightest about not needing to boil your must. I don't boil, and I like the results very much. However, there is a wide range of views on this, and many people who do boil, consistantly produce wonderful meads. Period recipes, especially, use a boiled must almost universally, and there are some masters of these styles out there who make great stuff time after time. And, of course, the efficacy of boiling regarding sterilization is very high indeed.


10-16-2005, 12:26 PM
To quote the eminent Dan McFeeley, who quoted the eminent Dr. Roger Morse author of: Making Mead (Honey Wine) - History, Recipes, Methods and Equipment (c) 1980, ISBN:1-878075-04-7

Just to clear the water a little bit ;D ;D ;D -- Oskaar's on target. It was demonstrated by none other than the late Dr. Roger Morse of the University of Cornell that boiling and skimming reduces nutrient content of the honey must. He documented his experimental results in his 1953 thesis on honey fermentation.

So, leave the crud in! It feeds the yeasties. Same thing with heating. It isn't necessary. In the same 1953 thesis, Roger Morse showed that meads made without boiling or heating the honey must remained microbiologically stable. Boiling the must is a Medieval technique, related to honey production methods during that same period. Interestingly, prior to that time, there is evidence that honey must was not boiled or heated.

And to quote the not so eminent Oskaar:

No need to heat your must.

You have some fine ingredients listed, heating will only kill some of the unique floral, varietal and individual characters and aromas of the ingredients you use.

I'd also advise against straining. Leave all the crud and such in the must. The more turbid the must, the better the yeast like it. Most yeasts are gear toward a turbid must, and the more clarified the must is, the less efficient the yeasts will ferment the available sugars.

Forget what you've heard about filtering your mead/wine in primary and secondary. Don't filter while racking. Once your mead/wine has finished fermentation and has had some time to age you can consider filtering. Until then, trust in the force!



Boiling/Pasteurizing: In my opinion and experience is not necessary unless you are reproducing period recipes or following a recipe from someone who's mead you like.

Also note that while honey, as mentioned below, is a very robust medium that prevents/inhibits contamination from normal microbial infection/spoilage, it is being diluted when you make mead. In doing so you remove it's inherent degree of infection resistance so that proper sanitization and aseptic technique must (get it?) be used in order to keep it from picking up an infection.

Hope that helps,


10-16-2005, 12:47 PM
Pasteurization is however a middle ground, between the Boil the life out of it and Just add water camps.

Holding the must at 161 F for at least 15 seconds will kill most organisms that may be present in the honey, while doing minimal damage to the nutrient content and varietal character of the honey.

Having used all three methods. I no longer boil any must I make and typicaly do not heat the honey other then in a water bath which makes it pour better. There are still time's I'll pasturize, mostly when adding fresh fruit.


10-16-2005, 01:02 PM
Pasteurization is indeed a middle ground. But you do denature protiens and kill enzymes when heating, which alters the character and in my opinon the flavor of the honey.



10-16-2005, 01:26 PM
I agree 100% Oskaar,

I remember talking to you about this when I first came to Got Mead. I made 3 batches from the same pot of must, first was pitched after blending the honey and water, second was pasteurized before cooling/pitching the third was boiled.

Cold blened taste the best, pasturized was second with noticable changes to the character and boiled cleared the fastest and needed the least aging.

But thats one test run, can't say it would work out the same again.


10-16-2005, 01:38 PM
Well, I wish I could say that I am making vinegar, since I happen to be out.

Hey Hedgehog,

I have Mother available, for making mead and dark braggot vinegar. The cost of shipping and the jar is all I ask.