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Old 11-16-2009, 11:46 PM   #1
neuron555
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Default Hop oil solubility

I asked this general question in the ingredients forum, but I'm not sure the underlying question was heard. I thought the brew chemists in here might tackle this.

The way I understand it, the hop oils are insoluable in the natural state. The purpose of boiling is to convert them to the form that provides the bittering, but this is at the expense of driving off the aromatics. Hence the late additions and dry hopping. The late additions, since there is little to no boiling (in the case of dry hopping) don't have the bittering, but the aromatics are there.

I gather that in order for the aroma to be released, there has to be extraction by the alcohol in the fermented beer. The question then, was whether hops or hop pellets could be steeped in a neutral spirit, ie vodka, then either filtered or washed with some hot water in a french press, then the extract added to taste in the secondary bucket. (in another thread there is a discussion of how much the ABV is changed by 4 oz of vodka - only about 0.2%)

I know that a purist would say just add the hops to the bucket like they always did, but I was trying to think of ways to reduce sediment, and so wondered if this would work. Is there anything wrong with the concept?

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Old 11-17-2009, 01:14 AM   #2
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Ethanol is one of the methods/solvents used to make hop extracts ("isomerized hop extracts"). I don't know if the extract made from ethanol can be useful for hop aroma... it may only be for bittering. I think they make a hop extract using CO2 that maintains aroma qualities.

So, essentially, you could do it, but I'm not sure of the quality of the outcome.

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Old 11-17-2009, 03:17 PM   #3
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I thought that in order to get the bittering qualities, the oils have to undergo isomerization, and that is the purpose of the boiling. The longer the boiling time, the more bitterness. The late additions do not boil and therefore do not contribute to the bitterness. It seems to me that doing dry hopping only imparts whatever qualities can be dissolved in room temperature beer. Since my reading indicates that the oils are not very water soluble, it must be the alcohol that is doing it.

Just trying to understand the process behind it.

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Old 11-17-2009, 03:34 PM   #4
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Quote:
Originally Posted by neuron555 View Post
I know that a purist would say just add the hops to the bucket like they always did, but I was trying to think of ways to reduce sediment, and so wondered if this would work. Is there anything wrong with the concept?
if by sediment you mean that crap at the bottom of bottle/keg then no this will not work. that crud is 99% yeast. the only way to reduce it is to filter out the yeast like the commercial brewers do then force carbonate.

a few ounces of hops are not going to contribute a significant amount of sediment and are either left in the brew pot or primary. if your concerned use a hop bag while boiling or put one on both ends of you siphon when you rack to a secondary/bottling bucket.
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Old 11-19-2009, 08:42 PM   #5
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You might be interested in this thread - http://www.homebrewtalk.com/f12/big-hop-flavor-1-3-hops-55721/

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Old 11-19-2009, 10:39 PM   #6
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The bittering agents are resins, not oils. The oils are the flavor/aroma components. Two very different beasties. The oils are dis-solvable in water, steam, alcohol and liquid CO2.

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