Bubblegum Flavours, can't find the culprit!

[NegFerret]

Hi,

I've recently brewed a Rogue Dead Guy clone using Wyeast 1272. I kept the temps down to 16c throughout the initial stages using my temp controlled fermentation chamber.

The whole brewing process beforehand went as well as it possibly could.

I tested temps sporadically through the fermentation process, with constant readings through the temp controller and wort temp readings using a thermometer, all around the 16c mark.

After a couple of weeks it smelled good.

By around 17 days the yeast had still not flocculated and there was still a fairly heavy krausen on the top. I took a sample and it smelled and tasted of bubblegum, with a gravity reading of 1016 (target 1013). I decided to increase the temp to 18c to try and get the gravity down and get rid of the bubblegum flavours.

Three days later I've come back to the beer. It's lost a further 3 points on gravity but unfortunately tastes and smells even stronger of bubblegum! I tested temps and yet again they're all within programmed temps controller 17.4c, fermentor 17c, wort 17.4c .

I had a similar issue a few months ago although that time it was more of a tcp flavour. I put this down to fermentation temps and taped the controller sensor to the side of the fermentor which seems to have worked as far as my temp readings are telling me.

Could it be a product of wild yeast? I have to open the top of my fermentor each time I take a reading or a sample as I don't have a tap, which isn't at all ideal.

Could the tube heater be too close to the fermentor causing it to heat some yeast far more than they should be?

Gah, this same question gets asked all the time...but I'm out of ideas.

 

[graysalchemy]

Butterscotch/popcorn buttery taste is attributed to diacetyl. I would leave it at about 20c for a few days after fermentation for the yeast to metabolise all the waste byproducts produced in the initial phases, a diacetyl rest.

Tcp is caused by chloramines and chlorine in your water reacting with phenols in the hops and may also be attributed to wild yeast infection, I think :wha: . Do you use a campden tablet in your water? This gets ride of chlorides and chloramines.
:thumb: :thumb:

 

[YoungJames]

I read a thread on homebrewtalk about something similar, the advice was just to bottle it and leave it for a while and it will probably come right.

My brief glance trying to find it was a wash out ... ill try again later

 

[london_lhr]

Hi,

Here is an interesting article about esters.

http://beersensoryscience.wordpress.com ... 04/esters/

Barry.

 

[NickW]

That a great read :thumb:

 

[NegFerret]

Butterscotch/popcorn buttery taste is attributed to diacetyl. I would leave it at about 20c for a few days after fermentation for the yeast to metabolise all the waste byproducts produced in the initial phases, a diacetyl rest.

Tcp is caused by chloramines and chlorine in your water reacting with phenols in the hops and may also be attributed to wild yeast infection, I think :wha: . Do you use a campden tablet in your water? This gets ride of chlorides and chloramines.
:thumb: :thumb:

Yeah I've had diacetyl issues before now, and learned how to deal with them. That's why I increased the temp by 2c, thought it'd solve the problem. I've now increased to 20c as you suggested. We'll see if they clean up.

I don't think this is a chlorine problem as the flavour isn't tcp.

Cheers for the post! :

 

[NegFerret]

Hi,

Here is an interesting article about esters.

http://beersensoryscience.wordpress.com ... 04/esters/

Barry.

I will definately be reading this, thanks!

My main frustration is how did this happen? I'm fairly confident it's not a temp issue as the controller was set at 16c and even if the wort were to increase 6c above that it'd still be within the target range for fermentation.

I'm bloody annoyed as the brewday went perfectly, everything was on target. This was meant to be a surprise for the missus as it's her bday soon and this is her favourite beer

Interestingly, the article suggest low aeration of wort could be a factor. Maybe also I could have stressed the yeast by making a weak starter (mine was 1.6l but may have had a low count due to not having a stir plate).

 

[london_lhr]

On another forum it was suggested that bubblegum flavours could be due to fermenting temperatures being too high OR pitching yeast at too high a temperature at the start of fermentation.
Just a thought. Where is your temperature probe situated?
Are you measuring fermentation temperature or the ambient temperature?

 

[NegFerret]

On another forum it was suggested that bubblegum flavours could be due to fermenting temperatures being too high OR pitching yeast at too high a temperature at the start of fermentation.
Just a thought. Where is your temperature probe situated?
Are you measuring fermentation temperature or the ambient temperature?

This is interesting. I don't usually care too much about pitching temp, so long as the wort is over 25c, but maybe I should. I've always thought that wort temp should be slightly elevated to get the yeast going, but if using a starter could this be detrimental?

 

[graysalchemy]

I do the oposite as once fermentation gets going it is exothermic and you can end up with dangerously high temps, and it is these initial growth phase of fermentation when off flavours are produced.

 

[Good Ed]

On another forum it was suggested that bubblegum flavours could be due to fermenting temperatures being too high OR pitching yeast at too high a temperature at the start of fermentation.
Just a thought. Where is your temperature probe situated?
Are you measuring fermentation temperature or the ambient temperature?

This is interesting. I don't usually care too much about pitching temp, so long as the wort is over 25c, but maybe I should. I've always thought that wort temp should be slightly elevated to get the yeast going, but if using a starter could this be detrimental?

As grays said pitching temperature is important. The making of a starter when using liquid yeasts is simply growing enough yeast cells to ferment your beer depending on the OG, see Mr Malty for more. When using dry yeasts you would normally use one packet, but at high OG's or lagers you would use 2 packets, again to get the required number of yeast cells to pitch, and dry yeasts should always be rehydrated before pitching. So after getting your pitching rate correct you then need to pitch at the correct temperature, which is usually a bit below the fermentation temperature. Each yeast has it's preferred fermentation temperature so it is yeast specific, but you want to pitch at the correct temperature to let the yeast go through the initial growth phase without producing off flavours, and with sufficient quantity of yeast you will be off to the races with a short lag phase. It is then the exothermic phase when you need to keep temperature control, after this you can finish the ferment at higher temperatures without risk of off flavours and once fermented out you would keep the beer for at least 4 days at this temperature to let the yeast clean up itself.

 

[NegFerret]

This is definately where I'm going wrong! I always pitch above fermentation temperature as this is simply the way instructions have advised me (see whitelabs vials). It makes total sense that in doing this I am creating off flavours.

At the end of the brew, after all my careful work, I tend to rush it as I didn't think it mattered so long as the temp was below 25c. In fact I thought it helped the yeast along to pitch at a higher temp. But it looks like I was undoing all that good work!

Thanks very much for helping me work through this. I will test on the next batch and add some pointers into my brewing check list.

:party:

 

[brewtim]

This is definately where I'm going wrong! I always pitch above fermentation temperature as this is simply the way instructions have advised me (see whitelabs vials). It makes total sense that in doing this I am creating off flavours.

At the end of the brew, after all my careful work, I tend to rush it as I didn't think it mattered so long as the temp was below 25c. In fact I thought it helped the yeast along to pitch at a higher temp. But it looks like I was undoing all that good work!

Thanks very much for helping me work through this. I will test on the next batch and add some pointers into my brewing check list.

:party:

I don't think pitching at up to around 5 C above fermentation temp has detrimental affects as long as the temp is brought down to fermentation temp within a few hours of pitching, probably not much longer than 4-6 hours.

Whitelabs prob recommend a higher pitch temp to encourage the yeast to start growth quickly thereby reducing the lag phase, it's during the growth phase (immediately following lag phase) that is critical for temperature, as this is where the yeast can produce off-flavours.

I have produced successful brews in this way with no off flavours using Whitelabs and Wyeast and starters, however you do need good temperature control to get the timing right and to get the pitching temp down to fermentation temp quickly enough, if no temp control is being used then I would pitch at ferment temp and not allow the temp to rise until after the growth phase has ended (beyond high Krausen).

 

[NegFerret]

Pitching at too high a temp is the only thing I think could be causing these esters. Wyeast 1272 isn't a crazy ester producer, and my temp control is good, with the wort generally staying within .5c of the target temps. I kept it at 16c for over two weeks and throughout initial stages of fermentation.

It could be that something went wrong with the controller in the first few days, but this is unlikely. I have a temp logger that I will use on the next batch so I can be sure there haven't been any massive sways in the ambient temp.

The only other answer is infection, but I really doubt an infection would give off this taste/aroma (from my admittedly limited experience).

It's bloody confusing this brewing business eh! :wha: :lol:

edit: I should say that I have no idea how high the pitching temp actually was, I just know it will most likely have been higher than recommended fermentation temps. If it was 25c with a starter added at high krausen I would imagine this could cause the issue. But the only way to test this is to gather more data next time and be more mindful of what I'm doing.