High Esters, why?

[Brewer Gerard]

I've been home brewing for three years now and i seem to be getting a higher level of esters in my ales than when i started. At first i though it was just my high gravity beers but it seems to be across the board now on any clean ales that i attempt.

I am making the presumption that this is a yeast related issue but i'm not 100% sure. The kind of beers i tend to like are clean ales like american IPA's with lots of hop flavour i.e. fermented with us-05/wlp001. The trouble is they're not coming anywhere as clean as i would like. I recently brewed a fairly simple APA and again i'm getting serious esters that i know won't dissipate.

The thing is i'm maintaining temp to within 0.3°C of a degree in my ferm chamber using an STC-1000 so i can't see how temp could be an issue. I have a stir plate and always make a starter dried yeast or not.

I don't do the whole oxygen stone thing yet so vigorous shaking of the fermenter is how I raise my oxygen levels. Can this make a big difference in undesirable flavours?

Any tips for getting clean beers outside of pitch rate and temp control, i'm a bit perplexed?

 

[JonM]

Maybe you just don't like Chico yeast? Try something else like 1272 or 1450 and see if that solves the problem.

 

[duboman]

You mention temp control but don't state what temp you are fermenting at.............
Also, are we talking ambient in the chamber or actual wort temp? There's a difference

I'm going to assume you are fermenting a little higher than you like if you are getting esters you don't like. My experience with those strains is a perfectly clean, ester free beer between 62-65F When you get to 67-69F the esters begin to come through.

The other thing to look at is hop selection. If you are using hops for flavor and aroma that are fruity/citrus like they can accentuate the ester profile of the strain used as well and perhaps that too is an issue.

 

[boydster]

Are you cold crashing and decanting your starters, or are you pouring the starter wort in with the yeast? That could be a possible point off entry for the esters.

 

[microbusbrewery]

It sounds like you're on the right track for healthy fermentations. A couple questions though, you didn't mention what temp you're fermenting at. I know the recommended range on WLP001 is 68-73F, but you can go cooler than that. Right now I'm using it in a Smoked Porter at 62F.

Have you calibrated the temp probe? Also, how are you taking the temp (e.g. ambient temp in the ferm chamber, probe submerged in a thermowell, probe attached to fermenter).

Are you decanting the starter wort before pitching? I personally don't use dry yeast but I've heard there's no need for starters because of the much higher cell count, but I doubt that's the issue.

 

[Demus]

Yes, poor aeration can cause various problems that can come through in flavor, especially in higher gravity brews. The gradual increase over time is an interesting piece to the puzzle. Does it roughly follow an increase in the gravity of the beers you are brewing? I'd highly recommend reading the book "Yeast", by JZ and C White. This book made a huge positive impact in my brewing.
The other possibility is "house flavors". Over time you can get build up on equipment (especially plastic) that resists cleaning and sanitizing. There's not enough to completely infect and ruin a batch since the yeast vastly outnumber the bad critters but there is enough to impact flavor. Closely monitor hoses, buckets and any other plastic gear for scratches and replace any damaged items.

 

[Brewer Gerard]

I'm fermenting at 66. The probe is taped under bubble wrap on the side of the bucket. My stc-1000 is reporting 18.5C and the adhesive thermometer on the side of the bucket is saying 66F so everything adds up there. I might drop it a tad for my next brew and see what happens. Yup, i cold crash and decant starters so the wort from the starter is miniscule but maybe an opportunity for improvement?

I do think the problem is exacerbated by a higher SG but i use those pitching calculators n all that jazz, any suggestions?

I think there may be something in critters in the plastic. I 'll have to get a new bucket for next brew. I presume any equipment used pre boil is safe.

Demus, I've bought and finished jamil's book a few months ago, great read.

I'll report back after next brew using new bucket and reduced fermentation temp

 

[helibrewer]

Are you doing single infusion or step mashes?

I use an SS thermowell for my STC-1000 probe. Put a small amount of mineral oil in the thermowell to improve temp conduction.

 

[Demus]

Demus, I've bought and finished jamil's book a few months ago, great read. I'll report back after next brew using new bucket and reduced fermentation temp

Do you remember the section about aeration? 10 full minutes of carboy shaking resulted in about a third of the recommend oxygen level. This could most certainly cause a less than healthy ferment and result in off flavors, especially in higher gravity brews. I agree Yeast was a great read, I think you'll agree the info doesn't do any good until you apply it to your brewing...

 

[Brewer Gerard]

It's just when you read on here you get people saying they ferment in a pig trough (exaggeration) and they get these wonderfully clean beers. It makes you think are you're getting carried away getting oxygen tanks involved. I suppose I'll have to try some different things instead of doing the same and expecting different results.

 

[Brewer Gerard]

Helibrewer,

I do single infusions for all ales

 

[Demus]

It's just when you read on here you get people saying they ferment in a pig trough (exaggeration) and they get these wonderfully clean beers. It makes you think are you're getting carried away getting oxygen tanks involved. I suppose I'll have to try some different things instead of doing the same and expecting different results.

It's your beer. Do you think the flavor you didn't like was caused by fermenting 2 degrees warm or by using only one third the recommend oxygen? Which sounds more likely to you? Brewing is controlling variables to your advantage. There are many to consider, and most are interrelated. I think it makes sense to look at the ones that are furthest away from recommended norms first, especially if you are having issues...

 

[Brewer Gerard]

Mmmmm. I'm gonna change one thing one brew at a time and record my perceived changes.

 

[Yooper]

It's just when you read on here you get people saying they ferment in a pig trough (exaggeration) and they get these wonderfully clean beers. It makes you think are you're getting carried away getting oxygen tanks involved. I suppose I'll have to try some different things instead of doing the same and expecting different results.

Hahaha! I know what you mean. I love those "I ferment at 80 degrees all the time and my beers are AWESOME!" threads. The thing is, I've never seen their awards or medals. If they love their pig trough beers, that's great. And that's why we all homebrew after all. I call that "ugly baby syndrome", as brewers like that love their beers, just as they love their hideous ugly babies, and that's ok.

Anyway, double check your pitching rate and pitching temperature. I've noticed the cleanest flavor with WLP001 (don't care as much for Wyeast 1056/S05) comes from cooling the wort to 60ish, pitching, and then letting the temperature rise to 62-64 for fermentation. With S05, fermenting under 65 has given me these weird peachy esters, so I only use it to ferment at 66-68.

 

[Thunder_Chicken]

I don't think ferment temperature and dissolved oxygen are separate issues. Warm wort holds less oxygen than cool wort, no matter how much you aerate. You really need to aerate chilled wort. And chilled might be ~ 60F or even a bit lower, depending on your strain.

 

[BigFloyd]

If you're unhappy with US-05/WLP001, give BRY-97 a shot.

Pitch at 60*F, ferment at 63-64*F a few days. When it slows down, gradually bump it up to 67-68*F for the finish. I'm drinking a summer pale right now fermented that way on BRY-97 and I'd use it again without hesitation. Very clean and allows the modest (1oz each) late additions of Citra/Amarillo in that beer to shine through.

I love those "I ferment at 80 degrees all the time and my beers are AWESOME!" threads. The thing is, I've never seen their awards or medals. If they love their pig trough beers, that's great. And that's why we all homebrew after all. I call that "ugly baby syndrome", as brewers like that love their beers, just as they love their hideous ugly babies, and that's ok.

I always figured that those folks came to homebrew from drinking Keystone Light and just don't know any better, but the "ugly baby" analogy makes perfect sense.

 

[Brewer Gerard]

I call that "ugly baby syndrome"

I was in that space for the first few beers. I think if you start to appreciate the quality craft brews out there it's impossible not to see the flaws in your own.

 

[Brewer Gerard]

Well I've gotten to the bottom of it after changing, as i said, one thing one brew at a time. I started, only in the last few months, steeping my fermenters in disinfectant for at least a week prior to a brew and the difference is staggering. I don't have any medals and I'm not saying I'm now officially the worlds greatest homebrewer but as big floyd said in one of the last posts, i can really get the hops 'to shine through' now. Most likely something was being harboured in the plastic.

I'm pretty sure nobody will care less but I said i'd report back just in case it steers even one poor sod in the right direction.

Thanks for all the responses on this one folks!

 

[DurtyChemist]

Cool. Glad it was what sounds like a sanitation issue. People stress that just as much as temp control and obviously it's more important.