# Butterscotch flavour from US05



## tbetland (7/3/13)

Done a JSGA clone BIAB type reciepe recently that I have done many times before with great success. This time as it neared fg it started tasting bad like butterscotch. I used us05 as usual. I think my air ration was not real great. Do you guys think this could be the problem or was it an infection. I upped the temp a few degrees but it did not help. I ferment in a temp controlled fridge so I don't think this is the problem. Any help would be great.


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## PeteQ (7/3/13)

It will be diacetyl

http://www.howtobrew.com/section4/chapter21-2.html

How to brew is free and an extremely good read

EDIT - if you bottle don't worry about it, it will disappear. If you keg up the temp to 22 degrees for a couple of days


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## Mardoo (7/3/13)

Yep, diacetyl. PeteQ's onto it with the How to brew. Look at the bit on the D rest.


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## Nick JD (7/3/13)

I sometimes get diacetyl with US05 in IPAs. Strangely not in APAs.

Might have something to do with the higher OG.


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## QldKev (7/3/13)

US-05 are hippies, don't stress them out man


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## Maxt (7/3/13)

I gave up on us 05 because of this.


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## Truman42 (7/3/13)

I've got a Fat Yak clone in the fermenter with US05 for 3 days now which had a taste I couldn't distinguish. After reading this I think its diacetyl also. A very buttery type taste to it. 
Dropped from 1.045 to 1.006 in 3 days at 20C. 

If I increase it to 22C now does it make a difference if I keep it there until next Wednesday?

Or should you only do it for a few days before cold crashing?


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## bullsneck (7/3/13)

I always do it as the krausen is looking like its dropping. I take a gravity reading and if it is 5 or points off I'll d-rest.


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## Screwtop (7/3/13)

Battled a sweet/honey/butter aroma in beers using 05 for years before listening to a podcast interview with Dr Charlie Bamforth. Now I pitch a little extra yeast, and wait two weeks minimum before chilling. 

Look up Vicinal diketones (VDKs). The two major VDKs of concern to the brewer are diacetyl (2,3-butanedione) and 2,3-pentanedione. Google Vicinal diketones and Charlie Bamforth.

Also had a similar result caused by an infection when open fermenting. Gave the inside of the fermenting fridge a good seeing to with bleach and vinegar solution, problem solved. 

Screwy


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## Truman42 (7/3/13)

So instead of increasing ferm temps to 22C Screwy your saying to just let it be for two weeks at 20C then CC?

That works for me.


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## Nick JD (7/3/13)

Easier to just use 1272. Tastier too. Less cloudy too.


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## Truman42 (7/3/13)

Nick JD said:


> Easier to just use 1272. Tastier too. Less cloudy too.


Ive never had this before with US05...And wont again either.


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## CONNOR BREWARE (7/3/13)

Truman said:


> So instead of increasing ferm temps to 22C Screwy your saying to just let it be for two weeks at 20C then CC?
> 
> That works for me.


Not a big user of US-05 but yeah my understanding is with ales you can complete a D rest at fermentation temps. However after once having had a beer judged with slight diacetyl and then completing an "off flavors" tasting session I noticed it in beers that I had previously thought were "D" free.

I now like to pop up the temp two degrees when I'm at about 8-10 SG points off FG. This giving the active yeast time to mop up the D. Particularly more important in highly flocculation yeast strains as you want cells in suspension to metabolise the yeast.


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## tbetland (8/3/13)

Thanks for all the help guys. I have set the temp to 22 and will give it a few days and see what happens.


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## Screwtop (8/3/13)

Truman said:


> So instead of increasing ferm temps to 22C Screwy your saying to just let it be for two weeks at 20C then CC?
> 
> That works for me.


Keep things simple around here Truy  15g of US-05 per 22L, ferment at 19°C, leave for 2 weeks. Drop to 10°C over 2 days, drop to 3°C - 4°C over 2 days, @ 3 weeks keg onto gelatine. 

This is my regime as it's not possible to raise above fermentation temp all year round. Prefer to use the same process every time....................................... Same each time = easy for me to remember :lol:

Screwy


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## Frag_Dog (8/3/13)

I've found that some slight agitation towards the end of fermentation seems to help with a D rest.

The last few times I've used US05 I give the fermeter as spin - pick it up by the handels and rotate it around. It kicks up the yeast a little. I try not and splash too much, but I guess its all CO2 in the fermember at that stage so it shouldn't matter.

Havn't had a problem with butterscotch / honey flavours since i started doing this.

PS I also bump the temp from 18C to 20C for D rest.


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## tbetland (8/3/13)

Well I'm officially of us05. Done the same brew as a double on Tuesday. Fermenting one with us05 and one with 1056. Us05 tastes like a tub of pure butter, krusen has gone and I think it's lawn food but ill give it another week. 1056 still has about a 2 inch krusen and tastes magnificent. I don't think I have an infection but who knows. But I'm gunna stick to liquid yeast from now on. I have no confidence in us05 anymore. Maybe it's just a bad batch.


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## MastersBrewery (8/3/13)

I uasually brew US-05 at 17 or 18 two weeks she's done, no special oxigination meathod, just let it splash about at ferm temp when filling the fermenter. Either sprinkle fresh pack or I'm filling a fermenter with US-05 all ready in there. 2 weeks bump to 26 over 3-4 days leave at 26 for 24hrs, crash to 3-4 for cold crash leave for a week. I do have to admit I've been a little lazy with cc and gel and so forth , but hey I'm drinkin it and I don't mind it cloudy for a week or two


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## drdaz (14/3/13)

I like the butterscotch in an APA


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## Nick JD (14/3/13)

Just to clarify, diacetyl tastes like the smell of buttered popcorn, not like a Werther's Original.


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## Damien13 (14/3/13)

I went to a tainted beer tasting, and the beer dosed with Diacetyl tasted butterscotchy/werthery to me. Some people can't even detect it in bucket-loads. So I think the perception of it varies. weird. Don't actually taste the popcorny buttery thing people talk about. I taste sickly sweet caramel.
I HAVE had a few blows to the head in my time, which explains a lot


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## Nick JD (14/3/13)

I wonder if the artificial butter flavour they added was sweetened, because diacetyl itself isn't sweet.


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## manticle (14/3/13)

Nick JD said:


> Just to clarify, diacetyl tastes like the smell of buttered popcorn, not like a Werther's Original.


Actually diacetyl, like many other compounds in beer will be perceived differently depending on the concentration, the beer it's in and the perception of the taster, including their threshold.

You might usually taste it as buttered popcorn but that isn't the only descriptor not is it the way it will always be perceived, even by you necessarily.

For example I have smelt and tasted acetaldehyde as the typically described green apple but more often than not, I get pumpkin skin and/or paint emulsion. Same chemical, different perception. This is both from doctored and undoctored beer samples.

If you ever do some kind of a fault/taint tasting session, taste the tainted beer at the beginning then leave the sample, covered till the end. re-taste. You may be surprised at how different qualities will be perceivable even after just an hour or so (suggesting temperature will also play a part as well as volatility).


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## brad81 (14/3/13)

This link: http://www.howtobrew.com/section1/chapter8-2-3.html might help to clarify why you might be getting those flavours. Are you finishing the ferment quickly based on the hydrometer readings alone?

I bought the hardcopy and read it a few times before I had any of my brewing gear in order. I heartily recommend it.

I've been leaving my ales fermenting (using US05 almost exclusively) in the primary fermenter for about 3-4weeks at a temp of about 20-22. I have yet to encounter any butterscotch/butter/diacetyl notes in any of them.

Like manticle pointed out, you'll notice some more fruit notes, but when using hops like amarillo and cascade, I believe it adds to the taste more than it takes away/overpowers.


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## Nick JD (14/3/13)

How many people here can taste butterscotch in margarine? I sure can't. Tastes a lot like butter though.

What's the primary artificial flavouring in margarine....


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## manticle (14/3/13)

I find marge and butter completely different. Similarity is colour (sort of) but flavour is not in the ballpark for me.

Flavour descriptors of compounds are often by psychological association too (although things like diacetyl are sometimes added to commercially avaiilable buttered popcorn, acetaldehyde is present in some acrylic paint emulsions, etc, etc).


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## tiprya (14/3/13)

The best example of diacetyl for me is chardonnay, some just reek of it.

Smells buttery to me, not butterscotchy.


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## Nick JD (14/3/13)

I used to do Boh Pils with a lot of melanoidin, as I got sick of pissing about with decoctions. I'm talking ~8% melanoidin.

In secondary, I'd always be resting the hell out of them, because they were very sweet and butterscotchy - 18C for days and days, and the "butterscotch" would invariably never fade. I gave up doing the rest because it made little difference. I even started thinking I might have a diacetyl infection, yet my APAs rarely tasted of butterscotch.

Then I made a Boh Pils without any melanoidin. Eureka ... tiny bit of diacetyl, eliminated by a rest. No butterscotch.

Started looking into what diacetyl actually tastes like. And what decoction-based melanoidins taste like.

Suddently occured to me also that I never ever got "butterscotch" in any beer that contained zero spec malts.

As always YMMV.


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## Bizier (14/3/13)

I often associate diacetyl with a form of sweetness. It gives a similar rounding-out sensation to back-sweetening and significantly alters my perception of dryness. Depending on concentration I get different things, but at the highest concentration (riddled with vdk) I get butter menthols minus the menthol.


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## Goose (17/3/13)

actually i struggle to asscociate diacetyl with popcorn, butterscotch or butter which are desirable tastes.... diacetly is its own vile animal in my mind and I can detect it at a thousand paces. I have always hated honey as a taste on its own and if you do you will be able to detect diacetyl's next of kin 2-3 pentanedione easily, and diacetly is very close....


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## Goose (17/3/13)

Artificial Butter Flavouring Linked To Alzheimer's Disease Risk 

*The Huffington Post UK* 

Posted: 03/08/2012 12:01 Updated: 03/08/2012 12:38 | By Kyrsty Hazell







A buttery food flavouring ingredient found in microwave popcorn could intensify the damaging effects of abnormal brain proteins linked to Alzheimer’s, a recent study has suggested.




Diacetyl (DA), an artificial food flavouring that gives popcorn and margarine its distinctive butter taste, encourages beta-amyloid proteins in the brain to ‘clump’ together, according to findings published in the Chemical Research in Toxicology journal.
This damaging ‘clumping’ process is a hallmark for Alzheimer’s disease.






*Artificial butter flavouring linked to Alzheimer's*

Researchers from the American Chemical Society also warned that DA could easily penetrate the so-called ‘blood-brain barrier’, which prevents harmful substances from entering the brain.
Furthermore, the artificial flavouring also stopped a protective protein called Glyoxalase I reaching the brain – a key protein that safeguards nerve cells.
"In light of the chronic exposure of industry workers to DA, this study raises the troubling possibility of long-term neurological toxicity mediated by DA," researchers said in a statement, reports _Science Daily_.
However, researchers added that the study focused on factory workers who worked at microwave popcorn and food-flavouring factories, and were therefore more exposed to the chemical.*What is Diacetyl?*Diacetyl is a natural byproduct of fermentation.The DA chemical also forms naturally in fermented beverages such as beer, and gives some chardonnay wines a buttery taste. Diacetyl, at low level, gives beer or wine a slippery feel. At higher levels one can taste a butterscotch flavour.


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## brentice (17/3/13)

I use Danstar nottingham ale yeast and have never had an issue with diacetyl. Only used US-05 a couple of times and it doesnt strike me as an amazing yeast. Then again its different strokes for different folkes :beerbang: :beerbang: :beerbang:


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## manticle (5/5/13)

Screwtop said:


> Battled a sweet/honey/butter aroma in beers using 05 for years before listening to a podcast interview with Dr Charlie Bamforth. Now I pitch a little extra yeast, and wait two weeks minimum before chilling.
> 
> Look up Vicinal diketones (VDKs). The two major VDKs of concern to the brewer are diacetyl (2,3-butanedione) and 2,3-pentanedione. Google Vicinal diketones and Charlie Bamforth.
> 
> ...



I was going to start a new thread but found this post.

I have a vienna lager that has a massive amount of diacetyl pre-lagering despite pitching an active 6L starter (albeit from 1 smack pack) at 4 degrees and allowing to rise to 7, then d-resting for a few days as high as 20. Should probably mention it uses a wyeast munich lager yeast, not US05.

A couple of things I have probably done wrong - d -rest should probably have started earlier - 1/2 -3/4 the way through rather than so close to FG and maybe bite the bullet and use 2 packs or push for an 8L starter (1045 starting gravity, 22 Litres).

Anyway I'm trying to work out ways to reduce the levels that are there and came across the interview I think Screwy is referring to.

http://beersmith.com/blog/2012/01/29/diaceytl-in-beer-with-charlie-bamforth-beersmith-podcast-31/


Worth a listen. I have another lager which is a bit of a leftovers so I decided to use the yeast cake from the vienna, some of which I put into a 1030ish starter, diluted from the same wort. A portion of that active yeast has gone into the vienna which is at 15 degrees and I will slowly drop the temp to 1 degree and lager for as long as I can.

Even if my beer still tastes like butter, the interview is a good one.


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## manticle (18/5/13)

An update on the above for anyone who cares. I top cropped some yeast from the next lager I got going (yeast cake from the first built into a starter) back into the first. I know lager yeasts aren't top cropping yeasts so no-one please try and tell me that.

Anyway the diacetyl is now reduced below my perception threshold so that works well. However the distant cousin - the 2-3 pentadione whatever thing that tastes like honey is very distinct. I don't hate it so i will likely just bottle it and drink it happily at home.

What is worth noticing is that the other batch was given a proper diacetyl rest. I raised the temp by about a degree a day once it was about 2/3 the way through, left it at 18 for 2 days and am now slowly dropping it back till it hits zero (again 1 - 2 degrees a day).

Not a hint of diacetyl or honey and exactly how I will do it again for all future lagers.


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## Nick JD (18/5/13)

I recently made a diacetyl bomb German Pils by pitching big and warm.

No amount of resting got rid of it.

When I pitch small and warm, it's okay. And pitching big and cold is okay too.

Not sure what's going on, but I think a big warm pitch the yeast spend the first day just churning butter.


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## KingKong (18/5/13)

I've finally worked out US-05 for my fermenting system. I used to get heaps of Butterscotch / honey . By doing everything I can to look after the yeast health and stress I have this far eliminated the butterscotch and honey taste for my perceptible levels. 

Things I changed to get there

1. Re-Hydrating as per manufacturers instructions and temps instead of pitching dry. - This helped BIG TIME, but some honey still present until a couple of months conditioning.

2. Using a D-Rest - Upping my temp from 18 to 21 half way through fermentation, through to complete fermentation, then back down to 18 for a week of conditioning. Pretty much solved the problem.

3. Using pitching levels at the higher end of recommended levels.

Don't have any problems with butterscotch or honey any more.

Not sure if it will work for everyone , but for me getting US-05 right has been the most satisfying part of my brewing to date. I'm now confident to move onto other ale yeast that might not be as forgiving.

...Not advice just my experience.


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