Bitterness, Boiling Kits & Toucanning.

[Brooksy]

Question 1: When a kit is boiled, what affect does this have on the original bitterness of the Kit?
Question 2: In your opinion, what is the resultant IBU rating when toucanning?

Information Question 1:
As far as I know, boiling will remove the volatile oils, the flavours and aromas, from the hop oil added at manufacture. I boil my kits for 30 mins to ensure that they are driven off. During this boil hops are added back e.g.
Hop schedule:
30 minutes 12gms 11
15 minutes 10gms 6
5 minutes 10gms 2

The resultant IBU rating of the brew IMO would be the kit IBU + added bitterness.

Information Question 2:
An arbitary boil time of 15 mins was used in the both calculations and
Utilisation percentages were SG 1035 = 13.2% and 1054 = 11%.
Coopers Kit IBU ratings were posted on site somewhere.
Doing a calculation on a kit v toucan bitterness I found that to get an IBU rating of 33 for a kit, transposing the IBU calculation we can calculate that a 52gm charge of 11% AA hops is required to get 33 IBUs for 23 litres at OG 1035.

For a toucan of the same brew, 23 litres at OG 1054, 104 gms charge of 11% AA hops will give us an IBU rating of 54 IBUs for the final toucan brew.

This result indicates that there is an IBU increase factor of 1.64 not 2.
These figures are taken from a K&K and a toucan of Coopers Bitter both of which are my figures.

Please discuss..........

 

[boingk]

ffffffffFFFFFFFFFFFF-ssssZZZZZZZZOOOOOWWWWWWWWWWWW!!!!!!!!!! Straight over my head :lol:

Well, not really.

First up I think that any calculations made with boiling the kits [which is not recommended in the preparation instructions] are erroneous in that they will be leaching bitterness out of the kits from the get-go. Sort of like buying water, boiling it, and wondering why you don't have the original amount left after an hour or so, and why the free-chlorine and other levels have changed.

Secondly, kits are designed to have 'X' amount of bitterness at a gravity of 'X', right? Well, if you alter that gravity such as with toucanning [which will affect starting and final gravities] you mess up the bitterness. So no, it wouldn't be exactly double the original, but it will be more than just 'one can's worth' of bitterness.

This next bit is purely experimental, although I found it interesting.

Also, if you divide the 1.054 SG result in #2 below by the 1.035 result in the same question [take it down to integers of 54 and 35 to exemplify], then you get 1.54 as a result....which is awfully close to the bitterness increase of 64% over the one-can result...

 

[Brooksy]

Also, if you divide the 1.054 SG result in #2 below by the 1.035 result in the same question [take it down to integers of 54 and 35 to exemplify], then you get 1.54 as a result....which is awfully close to the bitterness increase of 64% over the one-can result...

Interesting isn't it...... I took the long road

Do you reckon the 10% could be due to infermentable compounds within the malt not present when dextrose/sugar is used in a K&K?

Added:
Rule of thumb, I just add half to the original (X1.5)

For dissimilar kit toucans, I average the kit IBU ratings prior to calculation.

 

[RobboMC]

Why boil the kits, why not just use extract?

 

[Brooksy]

Why boil the kits, why not just use extract?

You can buy a kit (1.7kg) for $10.00 (and under when on special)
Plain malt costs $10.00 per kilo.

I'm a pensioner. As a matter of watching the pennies buying kits rather than kilos is the way to go.

It also ensures that the malt has been heated sufficiently for cracking. Most malt extracts are produce under vacuum so the temps aren't achieved.

If you find a nice kit, why not experiment with it to achieve your personal bewing zenith?

Use cheap kits (boiled) to experiment with the various varieties of hops so their flavour is prominent.

SWMBO must be listened to if I'm to continue brewing (experimenting).

Don't get me wrong, most of the name kits are very, very good but I'm fussy (or is that fuzzy - refer to my avatar) :lol:

Life's great.

Added: Sorry about the spelling, I'm sampling some experiments :lol:

 

[ale_snail]

wow im scared cos of all the high tech speak going on

 

[Brooksy]

wow im scared cos of all the high tech speak going on

It's cos I is p*ssed :lol: :chug: :lol:

 

[menoetes]

I got my first toucan on today and here's what I went with:

1 x can of Coopers Australian Pale Ale
1 x can of Coopers Canadian Blonde
1 x sachet of US-05 yeast

I actually boiled to APA can for 30 min in 2 lts of water in an attempt to reduce the bitterness, I'm not a big bitter drinker myself and hoped it might help. Filled to 25Lt and pitched dry yeast at 22'c after a little time in an iced water bath to get the temps down. It still tastes pretty bitter straight from the tap but I am aware that can change in brewing and some time in the bottle.

I'm just wondering if the boil would have done anything to reduce the overall bitterness or if I was just wanking about?

 

[slash22000]

Posted 23 May 2007

Posted Today

... :huh:

 

[manticle]

So a new thread on an already covered topic is a better idea? No-one would object to that surely?

Menotes - boiling the kit won't reduce the bitterness. If there were any late hop additions to the kit or hop extracts that contained any of the alpha acids, you would actually increase that bitterness.

If you want less bitterness, start with a lower bittered tin and add small amounts of fragrant late hops if you want hop flavour.

Boiling 2 cans of APA would be extra bitter - go a single one of a less bitter base.

And good on you for searching before posting.

 

[slcmorro]

^ thumbs up.

 

[menoetes]

Damn, I clearly didn't get the point when reading the original thread and have possibly bittered it up, ah well I live and learn. I'm sure I'll still enjoy drinking it one way or another.

Thanks Manticle, it seems lately that every time I post a question you're just waiting in the wings to jump in and give me the info I need. You're like my own personal wiki at the moment

Note: I didn't think there was a used by date on threads. I just wanted to post where original info was.