At what point do you decide to dump?

[Pataka]

I've had a batch of Mangrove Jacks Dark Best Bitter fermenting since boxing day that has been wrought with issues.

My first mistake was pitching the yeast when the wort was slightly too warm. I didn't get any fruity aromas, but I spent the next few days worrying about whether I had screwed up my batch before it even got started. The next few days were very warm here, and it took me a while to sort out even a crude form of temperature control. More of the same worry about whether or not I had screwed it up.

Fast-forward to about three weeks after it began, and I checked the gravity. 1.020. Still a significant amount to go. Fermentation was incredibly slow, and even today, is hardly any lower. It's slowing too, despite the fact it still has some way to go, and the summer heat continues, so it's not natural slowdown because of cool ambient temperature.

The starting gravity was lower than it should have been, so to have a fermentation stop so early was already going to mean a weak beer with unusual sweetness, but today I went to check it and smelt a noticeable vinegar smell. I'm picking it's an acetobacter infection in the early stages. There are very small amounts of crud on the surface.

It tastes... ok. When I say ok, I mean it doesn't taste any worse than it tasted a week ago (before any possible infection but with lots of residual sugar), but I'm really not sure I see the sense in bottling 5 gallons of beer that may well result in 5 gallons worth of bottle cleaning for zero gallons of drinkable beverage.

I've never dumped a batch before, so I don't know how you know when "it's time". Is it time?

 

[MaxStout]

If it's a aceto infection, nothing can be done to reverse that. Probably a dumper.

This would be a good time to revisit your sanitation procedures. Try to determine what can be done next time to prevent a repeat. So many vectors for infections, I cannot list them all, and I don't know what equipment you have. But take a good look at plastic items like tubing, buckets, etc. Plastic with tiny scratches can harbor stubborn germs. Go through in your mind and review everything you do on the cold side and what equipment touches wort and beer.

It sucks to dump 5 gallons down the drain (happened to me, too), but this is a good wake up call to step up the sanitation.

 

[GHBWNY]

I've had a batch of Mangrove Jacks Dark Best Bitter fermenting since boxing day that has been wrought with issues.

My first mistake was pitching the yeast when the wort was slightly too warm. I didn't get any fruity aromas, but I spent the next few days worrying about whether I had screwed up my batch before it even got started. The next few days were very warm here, and it took me a while to sort out even a crude form of temperature control. More of the same worry about whether or not I had screwed it up.

Fast-forward to about three weeks after it began, and I checked the gravity. 1.020. Still a significant amount to go. Fermentation was incredibly slow, and even today, is hardly any lower. It's slowing too, despite the fact it still has some way to go, and the summer heat continues, so it's not natural slowdown because of cool ambient temperature.

The starting gravity was lower than it should have been, so to have a fermentation stop so early was already going to mean a weak beer with unusual sweetness, but today I went to check it and smelt a noticeable vinegar smell. I'm picking it's an acetobacter infection in the early stages. There are very small amounts of crud on the surface.

It tastes... ok. When I say ok, I mean it doesn't taste any worse than it tasted a week ago (before any possible infection but with lots of residual sugar), but I'm really not sure I see the sense in bottling 5 gallons of beer that may well result in 5 gallons worth of bottle cleaning for zero gallons of drinkable beverage.

I've never dumped a batch before, so I don't know how you know when "it's time". Is it time?

Sounds like it could be aceto, but if it tastes "ok" now, and if you're not in a yank to re-use your equipment, it won't hurt to let it ride and see what it tastes like in another week or so. If it's taken on a more vinegary taste, then there's probably little hope for it. Taste (and not necessarily smell) will tell you whether or not to go ahead with bottling. But only you can determine that. If and when to discard is a matter of if it continues to go downhill.

 

[Pataka]

This would be a good time to revisit your sanitation procedures. Try to determine what can be done next time to prevent a repeat. So many vectors for infections, I cannot list them all, and I don't know what equipment you have. But take a good look at plastic items like tubing, buckets, etc. Plastic with tiny scratches can harbor stubborn germs. Go through in your mind and review everything you do on the cold side and what equipment touches wort and beer.

It sucks to dump 5 gallons down the drain (happened to me, too), but this is a good wake up call to step up the sanitation.

I'm fairly sure it came either from the airlock flowing in reverse and sending small amounts of water into the brew (plastic fermenter got squeezed a little too hard when fitting the lid after checking the gravity) or from one of the many vectors that exists when the lid is repeatedly removed to allow me to check the gravity.

The first lesson I've learned is, for now at least, to ignore the advice that 'the only way to tell if fermentation is done is the check successive gravity readings, and take no notice of the airlock'. My airlock was bubbling... just very very slowly. I believed it was fermenting, but had doubt in my mind over whether the bubbles were residual CO2 coming out of solution, pressure differences, or fermentation. I only got that doubt because of the oft-cited rule that it's bad to trust bubbling through the airlock alone, and that gravity is gospel. If I had ignored that advice, I'd have happily left it alone and would have a healthy brew right now.

The second thing I need to do is come up with some better procedures for testing gravity than what I'm using. I have a fermenter with a spigot, but using that to take samples is only going to draw things in through the airlock.

I'm by no means certain it's acetobacter, so might leave it for a bit. My living arrangements may be changing over the next few weeks anyway, so I'm not in any hurry to start another batch.

 

[Calder]

Vinegar/acetobacter, is irreversible.

Acetobacter needs oxygen to produce acetic acid. Add a few ounces of simple sugar to help create CO2. I think I would rack it to a carboy and add some sugar to create CO2 and see what happens from there.

 

[MaxStout]

I'm fairly sure it came either from the airlock flowing in reverse and sending small amounts of water into the brew (plastic fermenter got squeezed a little too hard when fitting the lid after checking the gravity) or from one of the many vectors that exists when the lid is repeatedly removed to allow me to check the gravity.

I'm going to put my money on the reverse airlock flow, unless you used sanitizer in it. Opening up to check gravity is a possibility if unsanitized items were dipped into the beer. Just popping the lid itself seems an unlikely cause.

That's the trouble with plastic--flexing it can push or pull liquid in airlocks.

 

[Pataka]

Vinegar/acetobacter, is irreversible.

Acetobacter needs oxygen to produce acetic acid. Add a few ounces of simple sugar to help create CO2. I think I would rack it to a carboy and add some sugar to create CO2 and see what happens from there.

So you're saying it's irreversible, but doing this would minimise the chances of it getting worse (by driving off the oxygen)?

Smelling it again now, I'm not so certain it is acetobacter. I think part of the 'acidity' in the smell was due to the amount of CO2 forming carbonic acid. The actual flavour I'm getting is more of an estery, fruit (banana) type smell, with perhaps a little nail polish remover thrown in.

I'd love to rack it into a carboy, but I don't have a 5 gallon carboy. Only a 1 gallon one, and it's currently full.

 

[Pataka]

That's the trouble with plastic--flexing it can push or pull liquid in airlocks.

Gotta say, I'm not hugely enthralled at my first experience brewing in a home brew kit plastic fermenter. If I had a carboy, I could rack to it in order to minimise headspace (provided it was the right size), but I can't.

With the issues I'm having at the moment, I could theoretically bottle it and see what happens, but because the fermenter is designed to be an all-purpose fermenter and bottling bucket with a spigot, it's not really conducive to adding dissolved sugar and mixing before bottling, as that will stir up the trub. Unlike with a system designed to transfer to another vessel prior to bottling, I'm pretty much forced to use carbonation drops. This isn't something I'd normally mind about, except in this case I'm potentially dealing with throwing away the cost of ingredients to make the batch as it is, so would rather do a low-cost carbonation at this point.

So plastic flexes, increasing the risks of infection, you can't see through the sides to see how fermentation is coming along, you must use carbonation drops.... the list of undesirables is growing. I'm now contemplating buying a glass carboy and using the plastic fermenter just as a bottling bucket in future.

 

[RM-MN]

Vinegar/acetobacter, is irreversible.

Acetobacter needs oxygen to produce acetic acid. Add a few ounces of simple sugar to help create CO2. I think I would rack it to a carboy and add some sugar to create CO2 and see what happens from there.

As long as you haven't racked this beer to secondary, you still have enough CO2 to prevent acetobacter from growing. Many people perceive acetaldehyde, a normal intermediate compound formed during fermentation, as vinegary. Others sense it as green apple or fresh cut pumpkin. Given time and the right conditions, the yeast will consume the acetaldehyde and turn it into alcohol. Let this beer ride. If it really is acetic acid being formed by acetobater, you'll know in another week or so.

If you racked this beer to secondary (you didn't mention it but you might have) then you have the conditions set for infections and your beer is screwed. Sorry.

 

[JohnSand]

I'm not convinced that it's infected, I don't think you are either. Unless you really need the equipment, let it wait. Revvy has a thread about waiting for beer to improve. I brewed a Pale Ale in the summer with Nottingham yeast. It got too warm, and tasted unpleasant. I left it in the basement, now it's good. Five months aged out the off flavor.

 

[Subdivisions]

Smelling it again now, I'm not so certain it is acetobacter. I think part of the 'acidity' in the smell was due to the amount of CO2 forming carbonic acid. The actual flavour I'm getting is more of an estery, fruit (banana) type smell, with perhaps a little nail polish remover thrown in.

Sounds like pretty classic high fermentation temperatures. The nail polish taste would be fusel alcohol. CO2 can give you a nose burn sensation like vinegar if you get a good whiff of it. Let it ride and bottle after the FG is stable.

 

[Pataka]

Last night, before I read any of these replies, I was 'replaying' the smell over and over in my head (you know what it's like). While I wasn't keen on removing the lid again, I did smell the odd bubble coming through the airlock to help try and narrow it down. The flavours, I concluded, were actually fruity (banana and juicy fruit chewing gum) along with some kind of solvent. The harsh acidity, as I and others have said, is probably carbonic acid thanks to the CO2.

The crud I mentioned on the surface, I forgot yesterday but remembered today, is something I've actually seen before. The first time I did a kit brew where I added hops and DME, I saw a very slight cap on top. Possibly it was hop resin, who knows. The point is, the beer was fine. This latest brew also had a dry hop addition, so it's conceivable that all I'm looking at is hop resin (if indeed it floats on top of the brew).

So I'll leave it where it is for now. Thanks for all the advice, everyone.

 

[Pataka]

Update on this about a week later. It's starting to smell much more normal again. Took a small sample to check the gravity and, while there's still fermentation to go, it's not tasting vinegary, and instead tastes just like beer.

So it must have been due to the higher temperatures. Woohoo. No dumping of batches for me.

 

[Pataka]

I had to bump this thread, as I think there's something to be learned from my experience.

I bottled this beer on the 3rd of February. I tasted the first bottle about 3 weeks after that, and it still had a strong smell of acetaldehyde. Each week, it got lighter and lighter. It's nearly 8 weeks since I bottled it, and it's tasting, smelling, and foaming just superbly. Carbonation was a bit light even a week ago. But now it's perfect. Giving the beer a slightly creamy taste, which I'm sure is the intention.

So the moral of the story is.... DON'T WORRY ABOUT HOW IT SMELLS OR TASTES WHEN YOU BOTTLE. GIVE THE YEAST TIME TO CLEAN UP AFTER THEMSELVES AND THEY QUITE PROBABLY WILL

This is going to get interesting, because I have my first all-extract batch conditioning at the moment and due to hit the three-week mark next week. Sounds fine... except the taste and smell was a little cardboardy before I bottled. I suspect oxidation. It will be interesting to see how that mellows over time. But I'll give it the same level of patience I think. It's only a 1 gallon batch, so I can't taste one bottle per week. But let's see how it goes.