Off smelling first batch

Hi there, I'm just in the midst of my first batch of home brew. Its a Munton's Pilsner Liquid Extract. I followed the instructions to the letter. I started fermentation around September 20th, just over 2 weeks ago. Everything has been going spot on.... Excellent fermentation, very vigorous and it subsided after about 48 hours. Did an hydromoter test and it came out at 1.08, which is exactly what the instructions indicated. It smelled awesome and tasted great, even for a flat, new beer. I was pretty excited about the finished product

I was going to move it to a secondary but most of the current advice I have read says just to leave in the primary for 3 weeks, which I was going to do. I did another hydrometer test about 4 days ago and it again read 1.08, which made me think it could even be ready for bottling. It sitll smelt and tasted good. I decided to leave it until next weekend (would have been about 3 weeks in the primary) and bottle it then.

But I checked on it today and it smells awful! not the yummy yeasty bear smell but some mix between bananas and paint thinner. I use those terms because they appear to be common smells. its hard to describe but it just smells "bad" and very "chemically". (i'm making up words)

My question is simply, has something gone wrong in the last little while? from what I have read, its often high fermentation temperatures that can lead to the off smells. I brew in our unfinished basement which is a pretty constant 18c (65f). I have a stick on thermometer and I was surprised at how warm the beer got during fermentation up to about 24 c (75f) but this was for about 12 hours or so. Was this the culprit? why would it all of a sudden begin to smell so badly after 2 weeks? I was going to simply stick to the plan and wait another week before bottling. Right thing to do, or any other suggestions?

thanks for the advice.

It's rather difficult to give an exact answer as there are so many possibilities as to what might have caused your current situation.

Certainly, having the temperature spike to 24 Deg. C, or so, during the initial, vigorous, fermentation stage can throw out off flavours and smells, even more so depending on the yeast strain used. How is it tasting at the moment??

I'd imagine you used the yeast that comes under the lid of the can. Do you know if it's just a generic ale yeast or a bonafide lager yeast? An ale yeast would have probably been at the upper limits of its temp range at 24 deg, C but a lager yeast would have been way out of it's comfort zone.

I have an ESB that I brewed at the beginning of summer, thought I'd managed to control temps ok with my swamp cooler but, it ended up having a smell that's reminiscent of "oil paint" . Bottled it for a couple of months now and after a week in the fridge it's mellowed a bit and doesn't taste too bad. Certainly nowhere near some of my better brews but still drinkable and, in fact, get's easier to drink as the time goes by. Kind of reminds me of a Suffolk strong ale that I've had.

What I find puzzling about your situation is that it smelled and tasted fine 4 days ago but has changed up on you in that time. It couldn't be that you didn't quite sanitize well enough what you used for drawing the FG sample, could it??

Hey, thanks a lot for the reply. I agree, whats most puzzling is that everything seemed fine only until recently. I too wondered if maybe I did something to it when I took the last sample, but I sanitized everything as I normally would. Doenst mean I didnt mess it up though! If I had contaminated it with my sampling tool, would that explain the smell?

I did use the yeast that came with the can. It wasnt labelled but I assumed it was an ale yeast as the instructions said to ferment at ale yeast temps, not lager yeast.

Too bad, I was excited about this batch. Think I will pitch it and start again!

thanks again for the input!

Before you decide to dump that batch it might be a good idea to have a look here

DON'T PITCH IT YET! Read this thread: https://www.homebrewtalk.com/f39/think-you-ruined-your-beer-set-your-fears-aside-74520/

You've already done most of the hard work. I say stick with the plan, bottle it give it 3 weeks to carb, then check again. Learning to be patient is one of the hardest things for new brewers to do, but it will pay off in the end.

http://www.howtobrew.com/section4/chapter21-2.html

First-read this regarding off flavors and see if you can pinpoint what it is you smell or taste and what may have caused that. It is unusual that a beer starts out being fine and then starts to go south. Usually the reverse is true as some off flavors can dissipate over time. I'm not saying dump the beer, I'm saying figure out what may be going on before doing anything rash.

BTW, I think you typo'd your FG reading as 1.08 would be a starting gravity, did you mean 1.008?

Thank you all for the advice... You're right my FG was a typo..

I took another sample today and its still reading 0.008. I had a taste this time. It tastes.... Cidery is the best description I think... and has a very strong alcohol taste to it. My understanding is these wont really mellow over time right? And if they do it will be only a bit and after a lengthy period? Honestly, aren't I better off just starting again!?

First, I have never had a batch turn out cidery so I can't speak from first hand experience.

Second, 75 F is too warm for most any brewing yeast and will almost certainly cause some off flavors.

Third, I once brewed a batch of American Amber that had a runaway fermentation. I over pitched from a slurry and pitched too warm. The temperature shot up to 78 F and the airlock was rattling like mad. I had no way to cool it down in time and the fermentation was over by the next day. During the hydrometer readings, bottling and the carbonation test bottles, it always had a yeasty, metallic taste to it. After it carbed up, the taste was still there. It wasn't bad enough for me to dump, but it was definitely my worst batch to date. Three weeks later, with a six pack to go, the off flavors parted to reveal a delicious, crisp balanced amber ale without the yeasty metal taste screaming over the top of it.

We are obviously not in the same boat, but my question to you is: What do you have to lose by waiting it out?