Ibu Adjusment For No-chill

[jiesu]

Thx for clarificaTION....... I think.

I have read a number of assumptions about the actual temperature that bittering of hops is severely reduced. Some say 80C some say 90C I think Chappo even metioned 70C in another thread. Anyone have evidence in favour of any of the above? It shouldn't be too difficult to quickly reduce the temp after boiling to 70C before pouring into the cube to negate the effects of no chill.

 

[haysie]

Thx for clarificaTION....... I think.

I have read a number of assumptions about the actual temperature that bittering of hops is severely reduced. Some say 80C some say 90C I think Chappo even metioned 70C in another thread. Anyone have evidence in favour of any of the above? It shouldn't be too difficult to quickly reduce the temp after boiling to 70C before pouring into the cube to negate the effects of no chill.

The closest I have seen to "evidence" would be a thread some time ago, TB had the IBU`S confirmed via his workplace, couldnt be fragged sarching it but its around. You make a very good point,what works on his system wont work on mine or yours. I ventured in to no/chill with what I think are relatively first hop beers i.e Alts, Reds and took things from there. KISS was my approach and still getting my head around it. Still back n forth between n/c and platechilling depending what i am brewing, yeast on hand, time time time etc. Evidence? be struggling!

 

[jiesu]

Ok So I have Found some SCIENCE!!!!

http://www.aussiehomebrewer.com/forum//ind...st&id=36896

Although the document only refers to temps above 90C.

So here are a few exerts from it.

Comparisons
between the model system and actual wort showed a significant
decrease in utilization when actual wort was used (49%
utilization for model system, 24% for wort). Utilization was
shown to decrease with increasing wort gravity, and a large
portion (51%) of the iso-alpha acids formed was found to be
present in the hot break.

Laufer and Brenner (5) also traced losses of bitter acids during
wort boiling and throughout the process to finished beer, finding
38% loss to trub, 35% to spent hops, and 10% to yeast and
covers.

The rate of conversion of alpha acids to iso-alpha acids was
highly dependent on temperature (Figure 4). For typical 100
C boiling conditions, 77% of alpha acids were isomerized
within 120 min. Temperatures of 130 C isomerized 100% of
alpha acids within 30 min of heating. A 90 min boil at 100 C
corresponded to a final iso-alpha acid concentration equal to
60% of the starting alpha acid concentration.

The results obtained indicate that the rate of isomerization
roughly doubled for every 10 C increase in temperature
(average change was 229% per 10 C increase).
Meaning approximatly half for drop of 10C

High temperatures quickly
led to degradation products, as evidenced in the dramatic
decrease of iso-alpha acid concentration beyond 18 min of
heating at 130 C.

While the rate of isomerization slowed at
temperatures below 100 C, substantial amounts of iso-alpha
acids were still produced at 90 C. This is significant if hot
wort is held at temperatures just below boiling after the kettle
boil is completed, while in the whirlpool, or awaiting transfer
to a heat exchanger.

 

[QldKev]

Ok So I have Found some SCIENCE!!!!

Although the document only refers to temps above 90C.

Good document on a real world test.

To answer your question about the 90c minimum test is from my research I understand a rule of 2.2x for each temp change.
So using the 90c @ 207 mins (from your supplied document), 80c would be (207*2.2) = 455 mins, your no-chill cube would not be held at 80 for long enough to matter. I like to use slow-chill to ensure I get under the 80c, what I deem critical point, as fast as I can. I have posted the 80c in a few posts prior. Also the other advantage of the slow-chill is to help with cold-break formation, which I believe does slightly effect the final flavor.

QldKev

 

[Bizier]

I will chime in that I only use NC for certain beers, either low hopped styles such as a mild with only a small bittering charge, or large IPAs that could do with a large 20-ish min flavour addition, and then dry hop for aroma. I figure styles requiring a finely balanced hop presence can be dealt with immediately using conventional chilling.

I am interested to try a beer employing the hybrid techniques of QLDKev and Ross.

 

[Beerbuoy]

Having now done 29 NC brews I just add 20 min to my hop additions in beersmith when I make up the recipe. I haven't found a brew that it didn't work on.

My only gripe with NC is not being able to do hop additions later then 20 min. Just means dry hoping is more important to get a nice aroma in your apa.

 

[cdbrown]

Having now done 29 NC brews I just add 20 min to my hop additions in beersmith when I make up the recipe. I haven't found a brew that it didn't work on.

My only gripe with NC is not being able to do hop additions later then 20 min. Just means dry hoping is more important to get a nice aroma in your apa.

Could you not crack open the cube after an hour or so and drop in the hops for the late addition - making sure to be sanitised of course

 

[Ross]

Thx for clarificaTION....... I think.

I have read a number of assumptions about the actual temperature that bittering of hops is severely reduced. Some say 80C some say 90C I think Chappo even metioned 70C in another thread. Anyone have evidence in favour of any of the above? It shouldn't be too difficult to quickly reduce the temp after boiling to 70C before pouring into the cube to negate the effects of no chill.

For all my "no chill" beers I actually cool with an immersion chiller to 75c & then transfer to a sanitised cube. The wort is still hot enough to nail any wild yeast floating around & should still have enough time at 60c+ to self pasteurise in the cube (not that I'm too concerned as pre sanitised). Using this process I have not found any detectable added bitterness to the final beer.

Cheers Ross

 

[Fourstar]

For all my "no chill" beers I actually cool with an immersion chiller to 75c & then transfer to a sanitised cube. The wort is still hot enough to nail any wild yeast floating around & should still have enough time at 60c+ to self pasteurise in the cube (not that I'm too concerned as pre sanitised). Using this process I have not found any detectable added bitterness to the final beer.

Cheers Ross

Thats pretty much my process but more so a natural temperature fall. i take off the boil and cover with lid, take pot inside, whirlpool (and add traditional 0 min hops if applicable), recover with lid and let rest for 10 mins. The temp is usually around 75-80deg and by the time its in the cube about 75~. if i want more hops, i then add a small amount to the cube. This is my 'whirlpool/hopback' addition.

 

[aaronpetersen]

If all my hop additions are with hop pellets in a hop sock does all the above still apply?

 

[Nick JD]

If all my hop additions are with hop pellets in a hop sock does all the above still apply?

The simple solution to all this is to remove your hops before you no-chill.

 

[aaronpetersen]

The simple solution to all this is to remove your hops before you no-chill.

Yeah, that's what I was trying to say. If all my hops are in a bag, which I remove after the boil, then I assume that I won't have to worry about the IBU's changing after that. Correct?

 

[felten]

Isn't there still alpha acids and such still in solution even after the hops are removed? Maybe its not a big deal though, I hope someone else can shed some light on it.

 

[WarmBeer]

Yeah, that's what I was trying to say. If all my hops are in a bag, which I remove after the boil, then I assume that I won't have to worry about the IBU's changing after that. Correct?

Sorry, but not that easy. The hop pellets are just a nice convenient carry-basket for complex alpha/beta acids (amongst other things). Pretty much as soon as they go into your wort, the alpha acids will be distributed through the liquid. It is the boiling process that isomerises these acids to produce the bittering compounds. While your wort is still > approx 80 deg C, it will still be changing the nature of these alpha acids.

So, pulling your hop bag out of the boil is just closing the gate after the horse has already bolted.

 

[Nick JD]

So, pulling your hop bag out of the boil is just closing the gate after the horse has already bolted.

So what's the level of un-isomerised alpha acids in a beer?

We might be just slamming horse's head in the gate. This might be one of those subjects where it's difficult to get a straight answer because an IBU either way really doesn't matter.

I'd be more concerned about all the people plugging into Beersmith the AA% number on their hops from 07...

I just read this in BS&P:

"If stabilized hop pellets (in soft packs) are kept at 4555 C for 1014 days, the
isomerization is complete and isomerized hop pellets are formed."

We can pre-isomerise our hops?

 

[Nodrog]

Could you not crack open the cube after an hour or so and drop in the hops for the late addition - making sure to be sanitised of course

Did anyone have any thoughts on this? anyone tired it?

Want to have a crack at dr smurto's golden ale this weekend, and will need to NC.

http://www.aussiehomebrewer.com/forum/inde...&recipe=502

Calls for hops at 60,10,5, 0, so I plan to do:

60 - adjusting qty to get same ibu with boil time at 75mins in recipe-acator

cube - instead of the 10m
5 min? don't know?
0 = dry hop as dr smurto suggests



Thanks all

 

[felten]

You could try adding all the hops except for the bittering into the cube

 

[jiesu]

It is important to note that hops are not sanitised in any way so either you want them in boiling wort (or very close to) or you add them when their is already alcohol in the wort. If you add them in after cubing or
Before fermentation is near completion you are gambling for an infection.

 

[barls]

jake hops are anti bacterial, hence why they are use in beer to increase the life span.
nodrog, id go for everything after 15minutes in the cube and the 0 minute as a hop tea in the fermentor at the same time as dry hopping.