Recognizing off flavors

[nitro0292]

I have been an extract brewer for about 6 months, and made about 7 batches.

In my last three batches I have detected an overly-sweet, fruity like flavor. I am not sure if this is a "green-apple" flavor or a "cidery" aroma/flavor or just "fruity-esters". To me the aroma and flavor is just cloyingly sweet, but not a malty-sweetness, more a candy/artificial sweetness.

I get the same smell when I open the fermenter, but it is not quite as fruity - and I can't taste it in the beer pre-bottling.

The first 2 brews in which I detected this flavor were an Oktoberfest and a bock, both of which were brewed at temps that were to high for the style (I dont have a way to keep temps down below room temperature). Both of these beers were in primary for 2 weeks and in secondary for 6 weeks each, bottles for at least 2 weeks before I tried them - aging has not made them better. OGs were in the 1.060-1.070 range (I don't have my notes with me).

This last brew was an ale with a clean liquid yeast (Wyeast American Ale yeast), and it was fermented at room temperature (65-72). Unfortunately I have detected this aroma and flavor again. OG was 1.078 and FG was 1.015, so I think the yeast is doing its job.

I have only used malt extract (except for bottling), so I am not adding excess sugar.

I have been assuming acetaldehyde (see my earlier post), but now that I have a nose for this flavor, I smelled and tasted it in a 4 month old pale ale.

I did not detect the aroma/flavor in this pale ale before, but now I do. I would think 4 months would be enough time for acetaldehyde to settle out?

The beer is drinkable, and other people like it - I don't however, because I detect this aroma and flavor (I don't detect this flavor in craft beers though, just mine), and it overpowers all other characteristics of the beer for me.

This has made me think there is bacteria somewhere. I'm trying not to be a paranoid NOOB but...I am aging the beer for at least 1 month in secondary (which is all the recipes call for) after fermentation has stopped.

I obviously sanitize all my equipment so if this is a bacterial thing do you have any tips on how to track down the source of infections?

Is it normal to smell a huge whiff of this same smell when you remove the top from the fermenter? I have gotten this smell from the fermenter after 4+ weeks in secondary and in bottles of the same beer after at least 2 weeks.

Does anyone have a clue as to what this off flavor is? Is it acetaldehyde or something else? How do I get rid of it if time does not help? If 4 months hasn't helped, will 6?

 

[DaveMcPhee]

Question: what temperature do you ferment at? There is always a way to keep your fermenter a little cooler than ambient. Search for "swamp cooler" on this board for one easy technique.

The green apple smell, or acetaldehyde, can often be cleaned up by the yeast over time. There is a ton of information about the pros and cons of racking to secondary, but instead of getting into it in this post, just leave your next brew in your fermenter for 4 weeks, then bottle/keg as usual. Compare your results.

 

[hamiltont]

If your fermentation (beer) temp is ~70 or above you could be developing esters. Think bananas or bubble gum. You can also develop fusel alcohol which has a bitter alcohol/solvent taste. Fusel alcohol can cause nasty hangover-like headaches. Cheers!!!

 

[Maxkling]

Most likely its too warm when fermenting...

I had the same issues with my first couple. Its almost like a real faint bubble gum flavor. The first time they guy at my LHBS brought up bubble gum I knew it was that.

 

[jonmohno]

I had the same problem my first three and i discovered i had pitched too high and gave me a wine like beer for awhile. It will mellow but takes a while and go 3 weeks with primary at least and use the higher degree temps for bottle conditioning.Its important to keep the temp inbetween 5 degrees and on the low end if you dont want those flavors.especially the first week. I usually bring mine up to temp on the last week before botteling when the yeast are finishing cleaning up. And this is definatley working for me because my bottleing sample was increadibly good with none of this appely taste.

 

[nitro0292]

I am currently brewing a 2.5 gallon batch of IPA. It was pitched at 68 with 2 vials of WL001.

When I took a gravity reading last week (1.020 from 1.079) the ambient room temp was 61, which I'm hoping is low enough to prevent esters, but it doesn't seem likely.

I will do another small batch and use the swamp cooler method. I used the swamp cooler method for a bock and got the same off flavors, but that was a lager yeast (even if it was supposed to "perform well at ale temperatures"). I will make sure to keep the t-shirt as wet as possible this time.

Will update - thanks for the help.

 

[Nova5]

a swamp cooler trick is only effective in areas with drier air. if you already have high humidity you will see no cooling effect and actually enhance the heating effect. moisture can transfer a immense amount of thermal energy. It doesn't have to be a solid water mass, it can just be high humidity. The difference between High and Low humidity is why south midwest states like to say "But its a dry heat" the reality is the sweat from the human body evaportates quickly in low humidity and cools the body. in High humidity the sweat can't evaporate so quickly due to the higher water content of the air. where you live will affect the ability of a swamp cooler to help you. In NM/AZ/UT/NV, there are TWO cooling systems installed in homes. a Air Conditioner, like most are used to. Rarley used. AND a Swamp Cooler. Regularly used during hot times. when using these you WANT to open the windows. that way you keep a flow going of hot air from the outside being sucked through the water panels, picking up moisture and getting dumped outside in the end. otherwise your home ends up being really unpleasent with all the high humidity air in it.

 

[mosquitocontrol]

As a general rule of thumb, the fermentation is usually at minimum 5 degrees higher then ambient(if not more). So even if the ambient temp is near the lower end of the yeast range your beer is likely too hot.

 

[BIGREDIOWAN]

Now I'm worried that my wheat beer fermented too high based on what you guys are saying. It's been in primary for 3 weeks this Thursday and I was planning on bottling on Thursday. Hopefully it cleans itself up some, but I guess I won't know until I taste it. Didn't mean to thread hyjack, just saying the temp thing is a concern of mine as well.

 

[nitro0292]

Nova-

I live in NYC...it is quite humid, especially during the summer. I cannot turn the heat down to the 50's, nor can I get it that cool in the summer.

If a swamp cooler won't work am I just not supposed to brew?

Is there any other way to control fermentation temp (in high humidity)?

 

[weirdboy]

Nova-

I live in NYC...it is quite humid, especially during the summer. I cannot turn the heat down to the 50's, nor can I get it that cool in the summer.

If a swamp cooler won't work am I just not supposed to brew?

Is there any other way to control fermentation temp (in high humidity)?

I stick my fermenter in an igloo cooler, fill the space between with water up to the level of wort in the fermenter, then I stick frozen water bottles in the water to lower the temperature as needed. I have found that once the temperature stabilizes I only have to swap bottles once or twice a day to maintain temps under most conditions. When it gets REALLY hot (I have no AC in my house) like 90's, then maybe three times per day.

 

[nobber]

I live in East Texas, I don't brew in the summer it is just to hot even with c/a on. but in the spring when it starts to become warm I place frozen water bottles and ice packs against the primary wrap it with a sleeping bag and sit it on a towel. If you use two liter bottles they will last all day; use at least three at a time. my house stays about 71 or so, but doing this I can bring the primary down to the low 70's high 60's very easy. I just wonder about your off flavor did it taste like the way a band aid smells? I get that taste when it is to warm. ........P.S I don't brew in the summer because of the fruit flys. Every time I open my fementer and transfer or bottle my beer here the come..

 

[nitro0292]

Definitely not band aids, it is all fruity/candy sweetness, all the time. I guess that would be a good thing if it is what I wanted.

I am currently into brewing 2.5 gallon batches (b/c it is just easier for them all to be consumed and I have limited space) to get as many brews as I can under my belt.

The 3 gallon better bottle is a size (7.5*7.5*20) that should fit in a wine chiller. Those things can get ambient temp into the low-mid 50's, and the temps are adjustable.

Has anyone attempted this? Do you think it would keep fermentation temps where they should be? Would there would be a problem with the release of CO2 gas inside the chiller?

 

[Bubba]

I live in NYC also and I just stopped brewing in the summer months.

 

[jonmohno]

Fermenting at higher temps with a wheat beer can be one of the cases where you may want higher temps.

 

[aseg]

Two vials of yeast for 2.5 gallons of wort? I've had apple esters in the past, but with European ale yeasts. What is your final gravity? Temperatures will definitely effect the yeast, but so will the malts. Are you using a bunch of crystal malts?

To everyone with heat issues: log onto craigslist and buy a chest freezer. Then truck down to your lhbs and buy a wattage regulator with a thermometer. Mine was $73. You can set the temp to anything you want and is accurate to +- 4 degrees. This was the best thing I ever purchased for my setup besides the auto-syphon.

 

[jonmohno]

You can also get off flavors with too much too little yeast.THe temp is very important too if its not in a temperature controlled environment your may not get what you want in your beer.

 

[nitro0292]

Right now final gravity is 1.018 from 1.079 with the 2 vials. I pitched a second vial b/c I did not have time to make a yeast starter.

Everyone seems to say that homebrewers chronically under pitch, so I thought "at least I will not be under pitching". Two vials certainly would not be necessary with a starter.

For the brews in which I have found esters - most recent used one smack pack (w/starter) two older ones each used 1 package of dry yeast.

The most recent one is drinkable, it was a Black IPA recipe but tastes more like an imperial stout because of the esters - not terrible just not what I wanted.

Could bottle fermentation at too high of temps also cause this? I don't taste the esters before bottling (but then again, I don't much before bottling other than hops).

 

[Maxkling]

I never really noticed the esters when I sampled from my primary in the past. Now that I know what I can look for I noticed it on my last batch at primary. My problem was I built a fermentation cabinet, I just did not take into effect the heat production from fermentation. It was a million times better than without the cabinet but there was still minute traces. Building a fermentation cabinet is very easy and can be very cost effective. Honestly though I will probably go the route of a fridge or chest freezer soon because Georgia summers are right around the corner and it will also allow you to lager.

I don't know how much space you have to work with but Temperature Control is one of the top 3 items that you need to have correct before you make a decent beer. I was very discouraged by my first batch, I knew about temperature control but I honestly didn't know/believe it had so much of an impact. Its one variable that needs to be easily controlled or you'll just be throwing money away.

 

[dcott]

Just to chime in to what's already been said, for help identifying flaws, I definitely recommend Randy Mosher's "Radical Brewing." He has a nice little section on beer flaws, and exercises to create trials to experience what the flaws are. It definitely helped me with my assessment of potential flaws.

 

[nitro0292]

OK...to update everyone. A buddy who I brew with has half the batch. We opened two bottles from the same batch and NO acetaldehyde taste...but they were gushers.

He was storing the bottles at a cooler temperature than I am, as I cannot get ambient down below 68 because I don't control the heat to my apartment.

Any ideas? Is this a gusher bug? Acetobacter infection?

We "sanitized" using one step. The label says it is a cleaner (but not a sanitizer) has anyone used Onestep before and can confirm whether it is or is not a sanitizer?

 

[jonmohno]

How much priming sugar?If they are well carbed if you didnt chill long enough you can get gushers.I havent yet even with 10 min ice bath to quick chill a beer.I also havent done the one ounce per gallon either except my dunkle weizen which said to do like 2.5 oz per my 1.7 gallon batch. I also used a lhbs version of one step on all mine. Its not by fda stadards a sanitizer but i dont trust the fda much anyway.

 

[nitro0292]

Standard 3/4 cup of priming sugar for 5 gallons. None of the bottles we opened have been chilled and only 2 were gushers, but neither of the 2 gushers had the acetaldehyde taste.

I am switching to StarSan going forward.

Could the cooler aging temps have something to do with the cleaning up of the acetaldehyde?