Hop Techniques

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Hop Techniques

Postby Skreza » Tuesday Mar 10, 2015 1:56 pm

Hi All!

So I am still fairly new to homebrewing however I now have a few brews under my belt and so far so good! I'm loving the brewing process and of course the final product!!

I am a big fan of Earle's Stone and Wood recipe http://homebrewandbeer.com/forum/viewtopic.php?f=11&t=10660

I am thinking of trying some different hop techniques to see what difference it has on the final product and how it effects flavour, aroma and bitterness.

So I am just wondering what techniques have you tried, which gave you the best results, what do you recommend, thoughts, opinions, etc, etc...

These suggested hop techniques/schedules are all using Galaxy [13.8%] just for simplicity of explanation and were calculated by BeerSmith.
Also note they are all around the 19 IBU mark and all done in a 4L extract boil with around 500G LDME.

1. Earle's hop schedule
10.00 g Galaxy [13.80 %] - Boil 20.0 min Hop 9.6 IBUs
15.00 g Galaxy [13.80 %] - Boil 10.0 min Hop 8.6 IBUs
20.00 g Galaxy [13.80 %] - Boil 0.0 min Hop 0.0 IBUs
Total IBUs = 18.2

2. Partial Steep schedule
10.00 g Galaxy [13.80 %] - Boil 20.0 min Hop 9.6 IBUs
20.00 g Galaxy [13.80 %] - Steep/Whirlpool 20.0 min Hop 9.6 IBUs
Total IBUs = 19.2

3. Entire Steep schedule
40.00 g Galaxy [13.80 %] - Steep/Whirlpool 20.0 min Hop 19.1 IBUs
Total IBUs = 19.1

4. Earle's hop schedule with a Cooled Hop Stand
10.00 g Galaxy [13.80 %] - Boil 20.0 min Hop 9.6 IBUs
15.00 g Galaxy [13.80 %] - Boil 10.0 min Hop 8.6 IBUs
Cool wort to around 60-64°C and steep for 20 mins. This should greatly reduce any IBUs imparted into the Wort and stop any loss of Myrcene which Galaxy is fairly high in.
20.00 g Galaxy [13.80 %] - Steep/Whirlpool 20.0 min Hop 0.0 IBUs
Total IBUs = 18.2


Appreciate any feedback!
Steve.
Last edited by Skreza on Wednesday Mar 11, 2015 4:33 pm, edited 1 time in total.
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Re: Hop Techniques

Postby drsmurto » Tuesday Mar 10, 2015 8:38 pm

Why is 10g of Galaxy boiled for 20 mins producing different IBUs in #1 and #2 schedules? If you add 20g of galaxy at 0mins in schedule #1 and getting 0 IBU, how is it that you are going to get 9.6 IBU from the same amount of hops added for a steep/whirlpool in schedule #2?

No way you'll get the calculated IBUs from a steep whirlpool in a 4L batch. The thermal mass of 4L is far too small and your temperature will drop too rapdily for the hop alpha acids to isomerise (with is what IBU is a measure of). Arguably it is very unlikely to happen on a 20-40L homebrew scale but that hasn't stopped the 'no chill adjustment' fan club from becoming very large.

I recently posted this on another brewing forum.....

It's your beer but on a homebrew scale the drop in temperature is so much faster than commercial breweries where whirlpool additions do add IBU. I've looked at the no chill function on homebrew software and it looks to me to seriously overdo the IBU contribution.

Isomerisation is a chemical reaction. Chemical reactions requires energy to surmount what is referred to as an 'activation barrier'. Once you switch of the heating the energy supplied to the system is no longer so the chemical reaction can only get the energy from the heat that is already in the kettle which is now dropping. I've previously linked to a paper that showed the rate of isomerisation at a number of temperatures. What the paper demonstrated was that for every 10C drop in temperature (from 100C) the rate of isomerisation drops significantly. What people who read that paper completely missed when making up this overestimation of IBU contribution, is that the authors used hop extract in a model buffering system rather than real wort. That is, alpha acids already dissolved. This has a massive impact on those numbers as the alpha acids are poorly soluble when adding them in the form of hops (pellets etc). It takes time for the lupilin to be released from the hop material and then for the alpha acids to dissolve in the wort. Until they dissolve they cannot isomerise. The chemical reaction, an intramolecular isomerisation, is also not a highly favoured one from an entropy perspective as it is going from a 6 membered ring to a more strained 5 membered ring. There is also a reduction in aromaticity (the chemical term relating to conjugation of single and double bonds in a molecule, not aroma). All these factors are NOT factored in to the calculations in homebrew software.

No chill cubes are incredibly hot to touch because the cube is not a good insulator so heat (energy) is being lost through the walls of the cube.

Unless you are adding massive amount of hops at flameout I see no reason to make any IBU adjustments as they will be well below the taste threshold.

So many myths in homebrewing.
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Re: Hop Techniques

Postby Guru » Wednesday Mar 11, 2015 7:34 am

Some very good explanations there Doc, I think I have learnt something today.
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Re: Hop Techniques

Postby Skreza » Wednesday Mar 11, 2015 4:56 pm

Thanks for the replies guys.

Sorry for the confusion in IBUs between 20 min boil in #1 and #2. That was my inability to copy and paste the correct info!
Have fixed that up now and they now show the same IBUs.

Let me explain a little further, I have made Earle's recipe a few times now which is basically method #1 and it works out great!
I was trying to boost some of the flavour of the hops which is why I started looking into different hop techniques. Like you mentioned in your own post my understanding was that if the wort is no longer boiling, only a small amount of IBUs would be imparted on the wort.

My first few batches I would follow method #1 and at flame out add the final 20g and start cooling the pot in a sink of ice water straight away. This obviously drops the temp very quickly and very little IBU from the final 20g is imparted on the wort.

I then decided that at flame out, after adding the final 20g I would try leaving it to sit in the pot for 20 mins before moving the pot to the ice water. Again I was under the assumption that the wort was no longer boiling so very little IBUs would be imparted.

The end result tells a completely different story to what I thought would happen... The final beer is unbelievably bitter! To the point that I just about can't drink the stuff!!
So while I doubt the software calculating the IBUs would be extremely accurate, based on this I believe there is definitely IBUs being added even in a small boil to have had such an affect on the final taste.

So that's when I started doing some more reading and have come up with method #2, #3 and #4 to try and was after some input from others that may have tried similar things.
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Re: Hop Techniques

Postby rwh » Friday May 01, 2015 4:31 pm

Another technique to look at if you're all-grain brewing is first-wort hopping: https://helms-deep.net/~rwh/blog/beer/?p=107
w00t!
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