No Chill IPA - Staggered IBU

[manticle]

Mine sits for 20, whirlpool (with any late additions) then sit another 20 before transfer.

Heat loss will vary depending on actual volume and amient temps but have previously measured 80+ going into cube.

I leave the lid on during this although it's a keggle and the keg handles allow heat and vapour escape while the lid resists dust/leaves, etc.

 

[Lyrebird_Cycles]

I leave the lid on during this although it's a keggle and the keg handles allow heat and vapour escape while the lid resists dust/leaves, etc.

I think you'd be surprised at how little of the cooling is from evaporation: to cool the wort by 5 degrees C you'd need to flash off 1% of the volume, which doesn't happen.

 

[manticle]

Leaving for 40 odd mins and having fairly small heat loss means I'm not especially surprised. My understanding, although much more layman like, is that unless actively agitating and/or encouraging a more efficient form of heat exchange, that volume of hot liquid will hold its thermal mass pretty well.

Mostly vapour escape for me at that point is the last exit route for volatiles although it's merely from structure of my kettle and available lid than anything deliberate.

 

[manticle]

Sitting in a surgery waiting room typing on a phone - I realise last post may not make sense.

 

[Rocker1986]

I put the lid over the top of my urn at flameout as well, with the hop spider in there it sits above it by about 20-30mm, so not completely closed off. It's more for stopping shit dropping into it than anything else. It stays on there until the urn is just about emptied, when it is taken off so I can see the hot break begin to move towards the tap outlet.

 

[rude]

MMM I transfer straight away into cube

Could you pour carefully & leave hot break in the cube would it settle at the bottom ?

I also leave in cube for 20 mins then into the pool

 

[manticle]

It will settle although pouring brings clumps back into solution.

 

[Rocker1986]

It does settle but I find as soon as the cube is moved it stirs it up again, hence why I avoid getting it in there in the first place.

 

[Fatgodzilla]

Enjoying this thread, even if it is going slightly off track. No idea what LC is talking but it's great to see knowledge and passion mix.
I turn off my Birko 40l and simply leave for half an hour. Don't whirlpool. The wort settles nicely and into cube fairly clear. My problem is what I think the thread started as .. Hop bitterness and no chill. I haven't made a decent high IBU brew as I get excessive bitterness without the flavour, so really would like someone to give me a simple hopping schedule for someone who biabs, no chills and doesn't own a pool or a bathtub. Appreciate that the cubes will cool at different rates depending on the air temperaure. Did I read somewhere someone has had a go at it?

 

[manticle]

What methods have you tried fatz?

I add all my flavour hops for hoppier brews to whirlpool so adding yours just prior to draining to cube would be similar.

Otherwise cube hop or argon method?

If none of those work, chill.

 

[Lord Raja Goomba I]

Yup, the point of the thread was to get an idea of how waiting for the wort to cool a little and see what effect it has on bittering vs aroma.

I had less a problem in Tas, but traditionally before then, had chilled all hoppy beers. Given that involved sticking pots in the sink and rolling cool (or lukewarm in a Qld summer) water around the outside of the pot, I would really like a method that would give the hoppiness, bitterness and the balance needed, but all be replicable.

Update: It's going into chill, from what it tastes out of the fermenter, balanced, a bit more hoppy, but balanced. The IBU was about 70 calculated ,and tastes pretty much around the 50 IBU mark. Once it's been carbonated in the keg, I'll get a better feel. But so far, looking promising.

Next attempt at this, will be more calculated using the formulae that LC has provided to tweak this.

 

[Fatgodzilla]

What methods have you tried fatz?
I add all my flavour hops for hoppier brews to whirlpool so adding yours just prior to draining to cube would be similar.
Otherwise cube hop or argon method?
If none of those work, chill.

I guess the biggest problem has to be the time the hops are in contact with the wort. I've never been much of a scientist, I'm more arsehole than anal. But I appreciate all hopping rates in all popular recipes are based on chilling the wort asap.

I've thinking about this all night (at my age dreaming/thinking beer is all I got) and have got to re-establish some simple brewing principles. Please confirm or correct in relation to bitterness and flavour.

1. The temperature of the wort is the principal factor that will affect oil extraction from hops
2. Once the hops are separated from the wort, what has been extracted from the hops will no longer change

Or to bring this back to LRG's original concept, will the slow cooling of a cube continue to affect whatever hop oils etc. has been extracted?

 

[contrarian]

I would think that temperature is important but there would be elements of boiling wort that would also have an impact so that changes in volatiles in boiling wort would be slightly different to wort at say 90C.

I would also speculate that the change of volatiles into bitterness compound would happen more quickly at boiling than at 80C.

I had trouble for a long time getting a flavour and aroma I was happy with from no chill but have finally made one I like and it had 50% of calculated IBUs at 60 and the rest added into the whirlpool at around 85-90C and that seemed to work.

I have also made pale ales that were 100% cube hopped that turned out well.

It really is guess work calculating IBUs with those kinds of additions as most calculators attribute no IBUs to 0 minute additions.

I would also suggest that even chillers have big variations in what they do after flame out that impact how long wort would be above utilization temperatures.

It really is trial and error on any individual system to get results you like.

 

[Fatgodzilla]

It really is trial and error on any individual system to get results you like.

Correct fella (and Happy New Year).

But what I hope LRG might eventually lead us fellow wanderers in the desert is a SIMPLE (read general rule of thumb) scale of measuring (roughly/approximately) the effect of hop isomerisation over the time it takes a cube to cool to pitching temperature. That Lyrebird bloke looks to have a key that will give him something to work with. LRG was thinking about a system based experiment, now he may be able to make shortcuts in the process.

Go man go.

But it is the results that's important, but its got to be made simple. I'm really the world's laziest brewer so don't want to have to overthink anything. I like plugging recipes into (say) Beersmith and making that brew. However, we "hot" cubists (brewers without swimming pools) have simply made 15-20 minute adjustments on hop additions and hoped for the best. Wouldn't it be good if we can use a better ibu / flavour determination based on something other than trial and error?

If work on no-chill and hop isomerisation can lead to some better knowledge that will lead to positive results (which in this case was a desire for repeatability of a recipe), then the world will be a better place.

I'm going to brew an IPA today rather than go to the Narooma Cup race meeting (the things I do for brewing, plus the weather looks dodgy) using the advice of Manticle and Contrarian and hope for a good brew (or at least something good enough to go into the next IBU case swap .. and I'll make a stout tomorrow as insurance). I will measure temperature at all levels of the production into the cube for the first time ever.

And think about brewing ............ :super:

 

[contrarian]

Happy new year!

A rule of thumb that worked would be great but I doubt there will be any great degree of accuracy without things getting fairly complicated. For starters, when describing recipes Brewers would need to be much more specific about their post flame out process in terms of time, temperature etc.

Hope the IPA comes out well!

 

[manticle]

As a very general rule of thumb Fatz:

1. Bitter alpha acids get dissolved into the wort when it's hot. Most activity happens above 80 deg with hotter wort increasing that rate.

2. Hop bitterness can increase even if the visible hop material has been removed ( say in a hop sock for example).

3. Hop chemistry is complex but you can still keep it simple.

4. Good luck. Brew on.

 

[Fatgodzilla]

Thanks Manticle, but please don't call me Batz. I'm way better looking than him. And I'm not a Queenslander -_-

 

[manticle]

Typo from my bat fingers on a vone

 

[Lyrebird_Cycles]

1. The temperature of the wort is the principal factor that will affect oil extraction from hops
2. Once the hops are separated from the wort, what has been extracted from the hops will no longer change

(3)* will the slow cooling of a cube continue to affect whatever hop oils etc. has been extracted?

* Paraphrase

1. Yes and no: it's complicated.

2. Not so: it will continue to change

3. Yes

There are five* things going on simultaneously: extraction of alpha acids, isomerisation of the alpha acids to the bitter iso alpha acids (IAA), degradation of the iso alpha acids to less bitter compounds, extraction of flavour compounds other than alpha acids and volatilisation (loss) of these flavour compounds.

The two extraction steps (1 and 4 above) are both included in extraction from hops. I do not know of any studies that give accurate estimates of the extraction rates involved, presumably because they are highly variable with things like lupulin gland size and structure, degree of rupture during processing and the activity of contact surfaces. If you've ever rubbed a fresh hop in your hand you'll know that the resins are released quite quickly and that they stick to everything.

Two further complications arise: the resinous material (AKA hop oils) can be released into the wort without dissolving (sometimes it's visible as oily spots) and since all hop components are poorly soluble but IAAs are more soluble than AAs, some of step 1 occurs after step 2 eg the alpha acids are isomerised in situ then the IAAs formed dissolve into the wort. This effect is exploited in pre-isomerised hop pellets.

All of these processes are influenced by temperature but only the temperature effect on steps 2 and 3 are well characterised. The extraction rates are also influenced by the boil vigour, stirring (if present) and such things as passage through a calandria.

It follows from the above that wort drawn from the kettle will have alpha acids that aren't yet isomerised entrained in it and further exposure to heat will transform these to IAAs, increasing the bitterness. This includes slow cooling time in the cube.


* Actually there are lots of other things going on at once but these are the five that concern us here.

 

[Fatgodzilla]

Even I understood (most of that). This last bit

It follows from the above that wort drawn from the kettle will have alpha acids that aren't yet isomerised entrained in it and further heating will transform these to IAAs, increasing the bitterness, including slow cooling time in the cube

Any idea of how much this might be? I know its a piece of string question, but talking about the big hops used in larger quantities and late hopping, such as in hoppy pales and IPAs (rather than the low volume for darker porters, stouts etc). So are we talking about, after say whirlpool waiting ( say 1/2 hour after active boiling has stopped) large enough quantities of these alpha acids in solution that the slow cooling process will continue to work on, or are the amounts small (or small enough not to have a realistic effect).