No Malt Or Hop Flavour After Conditioning

[vr4_psych]

Morning All,

I've been having problems with my last few beers losing malt and hop flavour and aroma after conditioning. For example, my last batch was a 15l IPA (1.06 to 1.011) with 400gm of hops added between 20 mins and dry hopping.

After priming and conditioning one mini keg for 2 weeks I tapped and had a beer. The beer was very hoppy and nicely balanced with malt sweetness. Two days later I pulled another glass and it had lost all hop and malt flavour and aroma and was now bland, grassy and barely drinkable.

To check whether it was just that keg I tapped the other mini keg from the batch and it was exactly the same. Both kegs were tested warm and cold without any variation.

First thing I've considered is oxidation as the blandness has a certain wet paper taste to it. not knowingly had an oxidized beer before though I have no basis for comparison.

Are there any infections that could be responsible? Can oxidation work that quickly?

 

[Wimmig]

Morning All,

I've been having problems with my last few beers losing malt and hop flavour and aroma after conditioning. For example, my last batch was a 15l IPA (1.06 to 1.011) with 400gm of hops added between 20 mins and dry hopping.

After priming and conditioning one mini keg for 2 weeks I tapped and had a beer. The beer was very hoppy and nicely balanced with malt sweetness. Two days later I pulled another glass and it had lost all hop and malt flavour and aroma and was now bland, grassy and barely drinkable.

To check whether it was just that keg I tapped the other mini keg from the batch and it was exactly the same. Both kegs were tested warm and cold without any variation.

First thing I've considered is oxidation as the blandness has a certain wet paper taste to it. not knowingly had an oxidized beer before though I have no basis for comparison.

Are there any infections that could be responsible? Can oxidation work that quickly?

That's a lot of addition. Though, the note of wet paper is a tell.

 

[vr4_psych]

That's a lot of addition. Though, the note of wet paper is a tell.

Which was a direct consequence of previous beers lacking hops as per the above issues.

 

[hoppy2B]

Which strain of yeast are you using psych?
Are you sure you don't mean 40gm of hops, 400 seems like a ship load?

 

[beachy]

I have no idea what your system is but a few years ago my mash tun had a push button tap which meant that to drain and recirculate every ml of wort was aerated while hot.

From this mash tun my beers were good for about 2wks but by 4-5wks old all hops and malt were muted and dominated by musty cardboard.
I do not want to start up another HSA debate because a lot of people believe it does not exist, but if you abuse the wort enough when it is hot I believe it does happen.

 

[jbowers]

Sounds like oxidation to me. Could either be from HSA or excessive exposure to oxygen somewhere in the transfer process. Do you rack to secondary? What is your procedure for kegging a beer?

 

[QldKev]

I'd check the gravity now after it's gone bland. Ensure the beer is room temp and gets flat before taking a reading. I'm betting it will be down to 1.000 = infection.

QldKev

 

[vr4_psych]

I'd check the gravity now after it's gone bland. Ensure the beer is room temp and gets flat before taking a reading. I'm betting it will be down to 1.000 = infection.

QldKev

Had not thought of that one Kev - will do that tonight.

Process is BIAB in a birko urn with standard tap. immersion chilled down to under 30C so don't think it could be HSA. Don't rack to secondary - use coopers racking cane to 6l tap a draft bottles. add priming sugar. once carbonated (typically 2 weeks), chill, swap cap for tap and add extra co2 as necessary for dispensing.

and definitely 400gm - actually morelike 450....

edit - us05. recently used mhb's pitching rate to much improved flavour (until this other flavour takes hold).

 

[Malted]

Are you sure you don't mean 40gm of hops, 400 seems like a ship load?

Hippy2B,

Do you think he would get the required IBU's for an IPA if he added 40g "between 20 min and dry hopping" in 15L of 1.060 wort?

Let's say for an IPA with an OG of 1.060 he might want an IBU/GU ratio of greater than, or equal to 1, therefore let's say 60 IBU. Lets say for argument he put 1/4 in at 20 mins, 1/4 at 10 mins, 1/4 at flameout and 1/4 in dry hop. 10 grams a piece for arguments sake. In Beersmith, with a 1.060 batch of 15L volume using Cascade 5.5% AA, I get a total of 9.1 IBU.
If I throw summit hops in instead as they have an AA of 17%, I get a total IBU's of 28.

If I say a 50/50 split, so it's 20g in at 20mins and 20g into dry hopping - Summit gives me 35 IBU's, Cascade 11.3 IBU's. The best we have done with 40g is a IBU/GU ratio of 0.58, if you subscribe to BJCP style guidelines you would want a minimum of 0.71.

Blind Freddy could see that it would be difficult to make 15L of a 1.060 IPA with 40g of hops; apparently he can see better than you.
I thought you grew a commercial quantity of hops? Whatsa matter, are you scared to use them?

 

[vr4_psych]

not to mention that was 15 into fermenter with about 5l lost to tub and hops etc. was roughly the same hops gm/l ratio as hopwired.

either way, still wasn't enough to get past this problem!

 

[vr4_psych]

Update - took another gravity reading with the refract and now it is down to 1.008. I think we may have something here...

 

[eamonnfoley]

I've had similar before:

Try:
1) Make sure your not overcarbing your beer, that can strip flavour very quickly.
2) How is your mash pH? It should be 5.4-5.7 measured at room temp. Check pH of finished beer (someone can do it for you if you dont have a meter). It should be 4.2-4.4 for ales.
3) Possibly infection or wild yeast if gravity keeps going down
4) Brewing water - Is it a good filtered source? Try campden tablets if straight from the tap
5) Avoid oxidation - most likely post fermentation.

 

[labels]

Good chance it's more than one problem. Oxidation plus a possible infection plus some other unknown factor. Paying absolute attention to detail every step of the way - and I mean really, really meticulous is probably the best way of eliminating this (these) problems in your next brews.

 

[hoppy2B]

Hippy2B,

Do you think he would get the required IBU's for an IPA if he added 40g "between 20 min and dry hopping" in 15L of 1.060 wort?

Let's say for an IPA with an OG of 1.060 he might want an IBU/GU ratio of greater than, or equal to 1, therefore let's say 60 IBU. Lets say for argument he put 1/4 in at 20 mins, 1/4 at 10 mins, 1/4 at flameout and 1/4 in dry hop. 10 grams a piece for arguments sake. In Beersmith, with a 1.060 batch of 15L volume using Cascade 5.5% AA, I get a total of 9.1 IBU.
If I throw summit hops in instead as they have an AA of 17%, I get a total IBU's of 28.

If I say a 50/50 split, so it's 20g in at 20mins and 20g into dry hopping - Summit gives me 35 IBU's, Cascade 11.3 IBU's. The best we have done with 40g is a IBU/GU ratio of 0.58, if you subscribe to BJCP style guidelines you would want a minimum of 0.71.

Blind Freddy could see that it would be difficult to make 15L of a 1.060 IPA with 40g of hops; apparently he can see better than you.
I thought you grew a commercial quantity of hops? Whatsa matter, are you scared to use them?

Yeah, I get what you're saying Malted. My unconventional brewing methods mean I get better utilization from my hops.

One thing that might be worth considering is your gas supply. Try carbonating with a different CO2 supply and see if the same thing occurs next time perhaps. If somehow oxygen got into the gas supply and beer was carbonated with it then that might result in beer going off quickly or so I assume.

I've actually given a fair bit of thought into the factors that lead to oxidation and how to prevent it occurring with the aim of producing a beer which will last a long time and age well. Am definitely leaning away from US05 for a yeast that will produce a more full bodied beer.

 

[Muscovy_333]

I'd check the gravity now after it's gone bland. Ensure the beer is room temp and gets flat before taking a reading. I'm betting it will be down to 1.000 = infection.

QldKev

Some reference

Paper/Cardboard
These are perceived in both the aroma and flavor and are primarily due to thealdehyde, 2-trans-nonenal. This compound has an extremely low flavor thresholdand is produced by the oxidation of higher alcohols. The threat of oxidation maybe reduced by minimizing splashing of the hot wort or of the fermented beerwhile racking or bottling. This flavor is never appropriate and is rare inhomebrew due to the reducing power of yeast, but it is a common flaw in manyold or abused commercial beers.


Grassy
This is the flavor and aroma of freshly cut grass or green leaves. Responsiblecompounds include the aldehydes hexanal and heptanal, which are produced by theoxidation of alcohols in the finished beer or the deterioration of improperlystored malt or hops. Some English and American hop varieties produce grassynotes if used in large quantities, but this flavor should not be a significantpart of the profile.

Read more: http://www.brewingkb.com/terms/-Off-Flavor...l#ixzz28WUyAXHk





View attachment Beer_Bacterial_taints.docx

 

[Malted]

Yeah, I get what you're saying Malted. My unconventional brewing methods mean I get better utilization from my hops.

Oh I see, you brew more than 20 Gallons and have forgotten the details behind brewing 15 Litres?
Either that or you can get 114.4% utilisation for a 15L batch (this being the utilisation in BS that gives me 40 IBU's for 15L of 1.060 with 20g of 17% AA at 20 minutes). The OP said he actually brewed 20L but I am sticking with 15L to match the previous examples. I will also use 17% alpha acid hops in my examples just because I am feeling generous. For this same reason I am going to use the BJCP minimum IBU value for an IPA (40 IBU's). (Note also that we don't actually get 100% utilisation of Alpha Acids, IIRC this 100% in BS represents 100% of the expected utilisation, rather than actual utilisation of AA).

Palmer's table shows an actual utilisation of 21.1% of AA's for hops boiled for 60 minutes in 1.060 wort. If those hops are boiled for an extra 60 minutes (120 in total) then the utilisation only rises to 23%. I am also led to believe that for every 10oC drop in temp below 100oC that isomerisation of Alpha Acids is halved (and therefore potential derived bittering is lowered by an amount)

Yes you will get extra bittering if you left your hops in the kettle for an extended period of time after flameout but the rate at which bittering compounds form is reduced as the wort cools. With a very large kettle it would naturally cool slower due to a larger thermal mass. 15L is probably not considered a large thermal mass.

If we calculate the required utilisation for an IBU of 40 from 20g of 17% AA hops in 15L of 1.60 wort

ibu's = (grams x AA% ) x Utilization % x 10
--------------------------------------------
volume

Where X is Utilisation %

40 = (20 x 17) x X x10
---------------------
15

X = 40 x 15
---------------
20 x 17 x 10


X = 17.6% Utilisation


Looking at Palmers Table 7 - Utilization as a function of Boil Gravity and Time (In previous link)

our 20g of 17% AA hops could give us 40 IBU's into 15L of 1.060 wort if we boiled them for about 36 minutes (Note: the OP said 20 mins). Also note, 20 minutes only gives us 12.8% utilisation.

If you did not chill your wort and left it to sit, bittering compounds would continue to be formed. However, it is logical that your wort would cool by itself (rate dependent upon things such as ambient conditions and equipment etc) and thus reduce it's potential for gathering bittering compounds. You would need the wort to stay at 100oC to continue, or increase from a 17.6% utilisation. We might conclude that as temperature drops, both isomerisation and utilisation drops. Ergo at a lower temperature, a longer period of time than 16 minutes (above our 20 minutes) would be required to give the equivalent utilisation and IBU's.

I note with my 50L system that as soon as I turn off the heat the wort temp will drop to about 96oC in the absence of an external heat source, when I whirlpool it will often drop another 6-5oc. It is not uncommon for my wort to be down to 90oC just by turning off the heat and giving it a stir. I would thus expect isomerisation of AA to be halved in a very short period of time after the boil time has finished (in my system).

Perhaps your unconventional brewing is that you turn off the heat to the insulated kettle, put a lid on it and walk away to come back the next day? Therefore your wort would stay in the high 90's (oC) for an extended period of time after flameout. Therefore you are getting higher apparent bittering in your wort than one might expect from a 20 minute addition? I have heard of people no chilling in the brew kettle and thus it is questionable as to whether this is unconventional.

I would contend that it is possible for you to get 'higher' utilisation rates of hops than I do, since I don't know what brewing vessels you use etc or what sort of brewing witchcraft you may be practising. I could NOT say that they might be 'better' utilisation rates. I would think your unconventional brewing as outlined in the paragraph above might well drive out flavour and aroma compounds (since it appears to be geared more towards bittering) and this might well suit the production of beers that you like. It probably would not suit the styles of beers I like.

Now if your brewing methods are 'unconventional', why would you assume that everyone else uses them? This seemed to be the inference from your initial statement to the OP. By definition, they probably would not be unconventional if everyone uses them. So if you are using the same brewing methods as everyone else, what sort of brewing witchcraft would give us 40 IBU's from 20g of 17% AA hops at 20 mins (reserving the other 20g for dry hopping) in 1.060 wort?

Edit: formatting.