Bubblegum Esters From Us-05

[cdbrown]

I brewed an aussie pale ale recipe 13/1 using a US-05 slurry of an alt. Recipe is below. Got 77% efficiency instead of the normal 70%. Fermented out without any noticeable esters, then sat cold in the fermenter for nearly 2 weeks prior to kegging. When I kegged it I noticed a slight bubblegum flavour and thought it might go with some carbonation. A few people have tried this and all thought it tasted like a wheat beer to the likes of hoegaarden. Any ideas on what the cause is?

057 Convict Pale Ale - Rev 2
Australian Pale Ale
Type: All Grain Date: 17/10/2011
Batch Size (fermenter): 42.00 l Brewer: Craig Brown
Boil Size: 46.60 l Asst Brewer:
Boil Time: 60 min Equipment: Browntown Double Batch
End of Boil Volume 41.60 l Brewhouse Efficiency: 70.00 %
Final Bottling Volume: 39.00 l Est Mash Efficiency 75.0 %
Fermentation: My Aging Profile Taste Rating(out of 50): 48.0
Taste Notes:
Ingredients


Ingredients
Amt Name Type # %/IBU
7.50 kg Pilsner, Malt Craft Export (Joe White) (3.2 EBC) Grain 4 86.7 %
0.70 kg Cara-Pils/Dextrine (3.9 EBC) Grain 5 8.1 %
0.15 kg Crystal Dark Bairds (239.9 EBC) Grain 6 1.7 %
50.00 g Pride of Ringwood [10.00 %] - Boil 60.0 min Hop 7 36.5 IBUs
1.00 Items Whirlfloc Tablet (Boil 10.0 mins) Fining 9 -
2.0 pkg Safale American (DCL/Fermentis #US-05) [50.28 ml] Yeast 10 -
0.30 kg Rice Hulls (0.0 EBC) Adjunct 3 3.5 %
9.00 g Gypsum (Calcium Sulfate) (Mash 60.0 mins) Water Agent 1 -
4.00 g Epsom Salt (MgSO4) (Mash 60.0 mins) Water Agent 2 -
20.00 g Pride of Ringwood [10.00 %] - Boil 20.0 min Hop 8 4.9 IBUs

Beer Profile

Est Original Gravity: 1.043 SG Measured Original Gravity: 1.047 SG
Est Final Gravity: 1.010 SG Measured Final Gravity: 1.009 SG
Estimated Alcohol by Vol: 4.3 % Actual Alcohol by Vol: 5.0 %
Bitterness: 41.5 IBUs Calories: 435.3 kcal/l
Est Color: 9.9 EBC
Mash Profile

Mash Name: Temperature Mash, 1 Step, Light Body Total Grain Weight: 8.65 kg
Sparge Water: 27.99 l Grain Temperature: 15.0 C
Sparge Temperature: 75.6 C Tun Temperature: 15.0 C
Adjust Temp for Equipment: TRUE Mash PH: 5.20

Mash Steps
Name Description Step Temperature Step Time
Saccharification Add 30.28 l of water at 70.8 C 63.0 C 80 min
Sacc2 Heat to 72.0 C over 10 min 72.0 C 10 min
Mash Out Heat to 78.0 C over 10 min 78.0 C 10 min

Sparge Step: Drain mash tun, Batch sparge with 1 steps (27.99l) of 75.6 C water
Mash Notes: Temperature mash for use when mashing in a brew pot over a heat source such as the stove. Use heat to maintain desired temperature during the mash.

 

[Steve@PMF82]

How much slurry?

How old?

Was it clean?

What was the ferment like?

One can only guess, but sounds like they yeast may have been stressed or some kind of minor infection / mutation?

Cheers

 

[cdbrown]

About 250-300ml of slurry. Alt finished ferment 4/1 at which point it was chilled for about a week. Brewed the pale ale and kegged the alt on same day. Allowed slurry to warm before pitching.

It's just a bit weird that I didn't note any esters from the ferment samples including the one before chilling. It only appeared after sitting cold at 4c for 2 weeks.

 

[malt_shovel]

About 250-300ml of slurry. Alt finished ferment 4/1 at which point it was chilled for about a week. Brewed the pale ale and kegged the alt on same day. Allowed slurry to warm before pitching.

It's just a bit weird that I didn't note any esters from the ferment samples including the one before chilling. It only appeared after sitting cold at 4c for 2 weeks.

How is the Alt tasting? Any sign of infection?

I have been reading up on hot fermentation since my barley wine got out of control during the first 48 hours. I recall reading that hot / fusel alcohols resulting from a hot fermentation can be converted by the yeast into esters during the maturation / conditioning stage. Different alcohols tend to develop into different esters so maybe if you think the beer could have been hot during the ferment that might be a cause. I will see if i can find the relevant references for you. The problem with this theory it that the conversion of high alcohols to esters needs active yeast, so I would have thought cold conditioning would decrease this rather than increase it as you observed.

The other thought was that maybe the slurry contained a significant amount of dead / poor performing yeast such that it was equivalent to under-pitching. Any long delays in start of fermentation?

Did you aerate the wort prior to pitching the slurry? I have heard some people pitching onto a US-05 yeast cake / slurry and not bothering to aerate because the dried yeast didn't require it which leads to all the same problems of not aerating the wort with liquid yeasts.

That's all I have got at the moment but certainly sounds like a yeast / infection problem.

 

[cdbrown]

Alt tastes great - no problems at all with it. 1 keg already gone.

Signs of ferment the following morning. Initial ferment temp at 17c for 3 days, then started slowly increasing temp up to 21c on the 8th day where it hit 1.009.

I don't pitch onto the cake. Swirled the slurry and poured off about 300ml into a measuring jug. Cleaned the fermenter and poured in the cooled wort from the keggle through one of those wort aerators.

 

[carpedaym]

A few people from this thread (mainly pg 3-4) mention ester production from US-05 during fermentations at cooler temperatures. Perhaps it is the same problem, albeit during bottle conditioning rather than primary fermentation.

 

[Nick JD]

Wild yeast.

 

[MattyH]

I brewed a fatter yak a few weeks ago with US05 and it tasted great out of the fermented for the first 3 day then the last gravity reading it tasted like a wheat beer I couldn't tasteany of the hops just a wheat taste. I bottled half of it but I'm sure something got in there and ****** it up. Maybe you've picked something up too

 

[Nick JD]

I remember watching a Wyeast vid (or reading something - brain like a sieve with a hole in it) where a guy talked about yeast either having or not having the gene to make phenolics.

US05 wouldn't. They'll all make esters if given the right conditions, but they either are, or arent able to make phenolics.

IIRC, lots of wild yeast make clovey flavours. So do some bacteria. Seems to be a well-used metabolic thingo.

 

[Thirsty Boy]

bubble gum from US 05 - well, bubblegum is an ester, so all the talk of phenolics is awry if you are describing your flavour correctly - then again, US 05 doesn't usualkly produce **** that would normally be described as bubblegum.

ferm temp way off would be a first guess - maybe a wild yeast (as in anoth3er brewing yeast you didn't clean awwy properly rather than brett etc) would be a second - and randon yeast variability would be a third.... but realistically, you probably ****** it up somehere.

US 05 at proper ferment temps should not be particularl estery - most likey you did something wrong..... you can guess what with minimal effort.

 

[mckenry]

cdbrown,
Here is a thread I started with an almost identical question. I too have had this wheat thing happen. If you read the thread, it'll explain a lot. Its not a long thread, but in the end, I think its infection.

 

[Nick JD]

bubble gum from US 05 - well, bubblegum is an ester, so all the talk of phenolics is awry if you are describing your flavour correctly - then again, US 05 doesn't usualkly produce **** that would normally be described as bubblegum.

ferm temp way off would be a first guess - maybe a wild yeast (as in anoth3er brewing yeast you didn't clean awwy properly rather than brett etc) would be a second - and randon yeast variability would be a third.... but realistically, you probably ****** it up somehere.

US 05 at proper ferment temps should not be particularl estery - most likey you did something wrong..... you can guess what with minimal effort.

"Bubblegum" is an American descriptor that I find causes a lot of confusion. To me "bubblegum" is like Wrigleys Juicyfruit (the yellow packet) - which is isoamyl acetate. I can get 1214 to spit this out in buckets.

But the "bubblegum" the Americans talk about is the pink, dusted strips that come with the baseball cards. That stuff is very phenolic-tasting. It's spicey, clovey, cimamon and a hint of wintergreen/anise.

 

[Thirsty Boy]

"Bubblegum" is an American descriptor that I find causes a lot of confusion. To me "bubblegum" is like Wrigleys Juicyfruit (the yellow packet) - which is isoamyl acetate. I can get 1214 to spit this out in buckets.

But the "bubblegum" the Americans talk about is the pink, dusted strips that come with the baseball cards. That stuff is very phenolic-tasting. It's spicey, clovey, cimamon and a hint of wintergreen/anise.

Good point - I've almost always seen bubblegum as one of the descriptors for ethyl butyrate, so thats what leapt to mind (thinking wrigleys too). Locked into a tasting room mindset - thanks for the bump back into the real world.