bubble gum from infection?

I'm having a bit of an issue with brews I'm doing with a friend that I'm hoping some of you can shed some light on. For the past 3 batches we've done together we've gotten bubble gum flavors and aromas in the beer. They all used different yeasts, and were fermented at different temperatures. I'm a bit stumped by this because everything I've read indicates that the yeast and the fermenting temperature are what causes the bubble gum aroma in a beer.

The first beer was a dubbel, using WLP-500 Trappist Ale Yeast that we had in a 68 degree room. We made an Imperial Blonde from a Brewer's Best kit while that was in the secondary. I can't remember what yeast was in it, but it was a packet of dry yeast, and again was fermented around 68 degrees. We brewed the third beer after we found out the first 2 had the bubble gum aroma, so we used Safale-05 and fermented it in the basement which was around 65 degrees.

Is this still just too high of a temperature to ferment without off flavors and aromas? I kind of doubted that this was the problem with the last batch considering the documents from Safale says that it's optimal temp range is 59-75. Is it more likely that there's some contamination or infection in either the plastic fermenting pail or the bottling bucket? Thanks.

Your problems are all caused by yeast. There is nothing else that I know of that will cause that flavor.

I wouldn't concider them a problem in your Belgian beer. It's a pretty common flavor in Belgians, usually because of the higher fermentation temps. This is what I've always noticed anyways. I'm no style judge though, so don't quote me on that.

As for the US-05....I've used it a few times and never liked it due to it's bubblegum flavor. Each time I fermented at around 66-68 degrees and they both had a slight hint of it.

How are you controlling fermentation temps? Also, how accurate is it?

The reason I ask is that some yeasts are pretty bad about causing off-flavors when you have temp fluccuations of more than 5-10 degrees.

Also, you should keep in mind that the ambient room temperature is NOT what your wort is fermenting at. A more realistic temperature would be about 8-10 degrees above the ambient temp outside your fermentor. So...even though you fermented at 68 degrees, you could have been into the mid-high 70's, producing a lot of fruity esters.

Thanks for the response. The temp is simply controlled by the ambient temperature in the room. My friend's house is air-conditioned and he keeps it at 68 all the time. I know the activity of fermentation can raise the beer temperature above this so I wasn't too surprised about the off flavors in the dubbel, but I was a bit by the IPA since it was kept at a lower temperature. I'm looking into a swamp cooler setup like I have at home for my own brews, and there's a possibility that we might be able to get a refrigerated unit to ferment in.

I feel better knowing that it is likely a temperature issue. I definitely did not want to go buying new equipment or try cleaning an infection out of what we have, and a swamp cooler is pretty cheap and easy.

Suthrncomfrt1884 said:

A more realistic temperature would be about 8-10 degrees above the ambient temp outside your fermentor. So...even though you fermented at 68 degrees, you could have been into the mid-high 70's, producing a lot of fruity esters.

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That's not quite realistic. While such a temperature difference has been observed anecdotally, it's somewhat extreme. The difference also depends largely on the yeast, the fermentation activity, the fermenter, the ambient temperature (i.e., as you ferment warmer, the difference tends to increase), and any number of factors that no one has ever counted. No doubt, though, you can get one heck of a difference, though.

Back to the OP, I would not expect bubble gum esters from contamination, although one cannot rule it out. How are you doing on wort aeration and pitching rates? Doing too little of either can lead to strong ester production. You also might want to look into yeast nutrient, especially if you are doing extract brewing (you didn't say).


TL

TexLaw said:

That's not quite realistic. While such a temperature difference has been observed anecdotally, it's somewhat extreme. The difference also depends largely on the yeast, the fermentation activity, the fermenter, the ambient temperature (i.e., as you ferment warmer, the difference tends to increase), and any number of factors that no one has ever counted. No doubt, though, you can get one heck of a difference, though.

TL

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I can agree with this. I mainly tell people about the 8-10 degrees above because it's yet another reason why you should be monitoring the actual liquid temps and not the air around the carboy/bucket. I've seen an American Ale 1056 jump my temps up to about 10-12 over my ambient, and other yeasts that only do 3-5 degrees above ambient, so you're right about it depending on strains.

Suthrncomfrt1884 said:

I can agree with this. I mainly tell people about the 8-10 degrees above because it's yet another reason why you should be monitoring the actual liquid temps and not the air around the carboy/bucket. I've seen an American Ale 1056 jump my temps up to about 10-12 over my ambient, and other yeasts that only do 3-5 degrees above ambient, so you're right about it depending on strains.

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And weather, too! A "hot" fermentation seems to get even more active, which produces even more heat. In the summer, with an active fermentation, it can be an extreme difference. Right now, my room temperature is 62, and my somewhat active primary is fermenting at 66.

My first thought with the bubble gum flavor was temperature, and then stressed yeast. If you're underpitching, that can cause some of those "fruity" flavors like bubblegum, from the stressed yeast.

It's not common to have those flavors in a relatively cool fermentation using a package of S-05, though. One package of dry yeast should be enough for a normal beer. I wonder if the temperature was higher than you thought- that would explain it.

A combination of too-warm temperatures and stressed yeast could definitely give you those flavors.

Thanks for the added info. I doubt underpitching was the problem at least for the IPA. It wasn't a particularly high OG, I think about 1.050 of the top of my head, so according to Mr. Malty 1 packet of Safale-05 should have been more than enough. The warm temperature is more likely at least.

Aeration is an interesting point though, we typically aerate by pouring the wort through a collander with relatively small holes. Generally the beer gets a good 4-5 inches of froth on top from doing this, but we have no way of really knowing that it's adequate aeration. Should this be enough? At this point we wouldn't be able to buy a pump and aeration stone.

stageseven said:

Aeration is an interesting point though, we typically aerate by pouring the wort through a collander with relatively small holes. Generally the beer gets a good 4-5 inches of froth on top from doing this, but we have no way of really knowing that it's adequate aeration. Should this be enough? At this point we wouldn't be able to buy a pump and aeration stone.

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that sounds like it would be enough aeration. you could always get a fish tank air pump, air stone, and inline air filter and use that to pump air through your wart. let it run for 20 - 30 min. people also use medical grade O2 and an air stone. that will give you WAY more than enough air but i have read that it causes the beer to taste like a "smaller beer". no idea if thats true or not.

anyway, how long are you aging your beer? this may be a problem that can be taken care of with a longer aging period. give the yeast enough tome to clean up after themselves.

Yeah, we're definitely letting the dubbel age a while. It's pretty disappointing with the IPA though since we made it with fresh hops and then dry hopped it in the secondary only to have bubble gum aroma instead of cascade. At least it's drinkable and not as prominent as it is in the other 2 beers.

I have had bubble gum flavors from US-05 before --- actually started as clove, and then the clove faded to a hint of bubble gum. Best I can tell I didn't cool the wort enough before I pitched my yeast.