View Full Version : Acidic/vinegar-y smell/flavor

Meady Nate
01-07-2012, 02:29 AM

Fairly new here, this site has been a great help for me so far in my mead making experience - thank you!!

Working on my 2nd and 3rd batches now.

My 2nd batch was started 7.5 weeks ago. It's been a fairly slow ferment (currently at around 4.5% out of a starting potential of 9%). I sampled it today and it has developed a slight vinegar smell and flavor. I am worried that the vinegar bacteria will sour my mead, and wondering if I should just bottle it now and start drinking it while it's still palatable, or if you think I should stick it out, leave it, and see what happens in a few more weeks.

The mead is a blueberry mead, flavored using natural blueberry tea.
I used the Lalvin EC1118 yeast, and about 10Lbs of honey for the 6 gallon batch. I do not use anything else. (My first batch of Elderflower mead turned out tremendously well!)

Anyways, any thoughts or opinions are greatly appreciated.


Chevette Girl
01-07-2012, 02:42 PM
My initial thought is that it's just going acidic like meads sometimes will, and you'll be fine because acetobacter need oxygen and if it's still fermenting it should be producing enough carboon dioxide to displace any oxygen in there...

My second thought would be to hit it with a campden tablet or two and then repitch another packet of yeast 24 hours later, you're NOT safe to bottle this the way it is, there's still residual sugar and it will continue fermenting in the bottles and if you're lucky you'll only get popped corks and a big mess, wine bottles aren't rated for the kind of pressure that will build up and if the cork doesn't give, it will explode.

7 weeks is a long time for it to have only made 4.5% alcohol, there's something not right with the progress of this batch unless you're keeping it very cool, even without nutrients that yeast should have blown through a 9% must in a week...

However, to get a better idea of what's going on, how have you treated this must? What temperature has it been at, did you heat the must or mix it cold, how often did you aerate, is it under proper airlock, is the specific gravity still changing or has it stopped?

Welcome to the forum! Nice to see another Canuck on here. Go, Getafix!

Medsen Fey
01-07-2012, 03:05 PM
It is not likely to be an acetic acid bacteria problems at this stage. The active yeast will bind up all the oxygen in the must and the bacteria cannot grow. The problem with acetic acid bacteria really starts after fermentation, during storage, and can really only develop if the mead has oxygen for the bacteria to grow. When acetic acid bacteria do grow, the first smells they tend to produce are more like nail polish or sulfur odors.

If you are adding blueberries, unless you treat them, they will contain lactic acid bacteria that can sometimes cause sourness. Again, with EC-1118 they would be unlikely to thrive at this stage. It sounds like you were just using the tea though.

The yeast themselves cause sourness and a lot of odd fermentation odors that are transient in nature. If you have not provided the yeast with any nutrients, that could cause them to be stressed and produce odors. Did you add any nutrients?

Meady Nate
01-07-2012, 03:14 PM
Hi, thank you both for your replies!

I think the slow fermentation might have been due to some shock when I was making it. I think the must was too warm (from liquifying the honey in water) when I pitched the yeast. Then, I had made too much must to fit in the carboy, and so ended up losing some yeasty goodness, so I think both those factors have led to less-than-ideal yeast populations. I aerated lightly the first 3 or 4 days, as best I could.

Temperature has been moderate, it sits near the furnace grate in the kitchen, under the table, covered to keep it dark.

It is under an airlock, bubbles currently every 12-13 seconds. The fermentation is slowing, as it has been at the 4-4.5% since around Christmas.

I will consider your suggestions Chevette Girl, thank you!


Meady Nate
01-09-2012, 06:35 PM
Well, I had my friend sample my mead (he is a fermentor of many wonderful things) and he didn't think it was so bad. The acidic flavor is there, but it is not over-powering. He thought it might be due to the blueberry tea, which is 100% natural ingredients, so there is the possibility of the lactic acid coming through. The tea also has citric acid in it as well.

There's still the question of the slow ferment though, so he suggested I just add more yeast, so I pitched another packet of champagne yeast yesterday afternoon, to see if I can get the last half of the sugar eaten up quickly.

I will keep you updated!

Thanks again!


Meady Nate
01-10-2012, 10:15 AM
I think temperature and yeast was the main factor in the slow ferment

I moved the carboy closer to the furnace grate last night and the fermenting took off, she's bubbling very quickly again.

Temperatures here in Calgary have been around +5 C for the last month or so, so we kept the house fairly cool, around 18-20C. It would have been cooler where the mead is kept, so I think that is why it has been so slow. It's getting colder again, so the furnace is getting turned up!

Excited to have this mead finish up soon, I've been waiting patiently for a while!