Question about hops utalization.

I'm not sure if this question has already been addressed on this form, but I haven't been able to find a clear answer. If alpha acids effect bitterness and the oils effect aroma, how does the flavor factor? Wouldn't the optimum be to extract both the oils and acids? couldn't you extract all the oils from a french press first, pour the water in your bucket and then boil the hops? I have tried this myself and it didn't seem to effect the flavor, so I think I am missing something. Is there something other then oils and acids that effect flavor or is a french press not sufficient to extract the oils?

The mechanisms at work here are a bit more complicated than simple extraction of the hop oils.

For one there are oxidation processes during the boil which create less volatile aroma compounds that better survive longer boils. Due to their different levels of volatility, different hop oils are boiled off at different rates. This affects the hop character you are getting from the beer.

I’m not saying that your approach will not work. I’m just saying that the hop character you are getting from this may not be what you are getting from conventional use of hops in the boil.

Kai

Thanks, I appreciate your response. Would using the french press to extract the oil work if I pour the water back into the pot at the end of the boil? Will this help maximize the flavor? I'm still a little confused on were the flavor comes from since the oils enhance the aroma and the acids effect the bitterness. Does aroma plus bitterness equal flavor?

Flavor is the combination of taste and aroma. The taste response comes from your tounge and the aroma part comes from volatiles released in the mouth that get to your olfactory organ though the nasal cavity. When you have a beer next time, simply slosh it around in the back of your closed mouth and breath out. You’ll notice hop aroma.

Since your mouth is warm, more compounds are actually released compared to the beer in the glass.

When we talk about hop flavor it also includes characters like astringent, resiny, smoth. Those come less from the aroma oils.

You may want to check if you can find articles/posts from the years of the hop-crisis. Back then brewers tried to get the most out of their hops and may have used the procedure you described

Kai

-https://www.homebrewtalk.com/f12/big-hop-flavor-1-3-hops-55721/
This old thread revolved around an Englishman that did an experiment that concluded tasters preferred the conventionally hopped sample. The problem is, he didn’t compensate for the 300-400% better utilization of the technique they took to calling “Hot French Randall.”

I think the conclusion they should have come to is that Englishmen don’t care for wildly overhopped American pale ales.

I have been using the French Press method in lieu of dry-hopping for some time. Here’s how I do it:

Put an oz of leaf hops in the French Press
add 1 cup beer
Slowly add 2 cups of boiling RO water until the temperature reaches 75º C, 167º F.
Cool to room temp and add to beer before bottling.

Like Kai says, it’s not the same as late hop additions. It’s quite a bit like dry hop.

I wouldn't think a French press would extract more than a small fraction of the essential oils. For that job steam distillation is probably the best method. The oil it produces is really wonderful stuff. Amazing aroma and flavor and not the least bit bitter. I have only done this a couple of times as a curiosity usually giving the oil to female brewing friends as a perfume but I would imagine it would be fantastic for 'dry' hopping.

Good to know, AJ. Where do I get one of those? Does it come with a mass spectrometer?

I’m guessing the extraction is pretty low for everything we do as late additions. It would be fun to see an experiment on this. You know, time temperature, pH. Sciencey stuff.

I have one more question. Does the flavor that is unique to each hop come from the oils or the acids? Also, do you need hot water to extract the oil from the hops?

Most of the flavor and aroma is coming from the oils. But a significant part of the hop character can be expected to come from the balance of the different bitter resins.

Hot water should work better, but alcohol should do an even better job.

Kai

I wonder about that. When hops are extracted to include everything then organic solvents or hypercritical CO2 are used but AFAIK when one is after just the oils steam distillation is the method of choice. It's not that it does a better job of extraction (I'm thinking) so much as that it gets only the oils and not the resins.

Good to know, AJ. Where do I get one of those?

Click to expand...

The rig looks like this: http://www.pbase.com/agamid/image/132252629

Does it come with a mass spectrometer?

Click to expand...

Not usually but sometimes you can work a package deal.

ajdelange said:

I wonder about that. When hops are extracted to include everything then organic solvents or hypercritical CO2 are used but AFAIK when one is after just the oils steam distillation is the method of choice. It's not that it does a better job of extraction (I'm thinking) so much as that it gets only the oils and not the resins.



The rig looks like this: http://www.pbase.com/agamid/image/132252629



Not usually but sometimes you can work a package deal.

Click to expand...

Were can you buy one of those? Or is it something you have to build yourself?

ajdelange said:

I wonder about that. When hops are extracted to include everything then organic solvents or hypercritical CO2 are used but AFAIK when one is after just the oils steam distillation is the method of choice. It's not that it does a better job of extraction (I'm thinking) so much as that it gets only the oils and not the resins.



The rig looks like this: http://www.pbase.com/agamid/image/132252629



Not usually but sometimes you can work a package deal.

Click to expand...

Also, based on your description of this method, it seems like this would also break down the acids and make them useable. Could you poor the left over liquid that is in the flask into your primary fermenter and then add the oils when it finishes to get both the oils and acids?

The closest thing I can find (which looks pretty darn close) is at http://www.gogenlab.com/products/pyrex-r-oil-dilution-distilling-receiver. I'm in Canada right now so I can't look a the thing and see who made it.

As to what's left in the flask? Don't know. I was only interested in the oils. It has occurred to me that it takes a long time for all the oil to be collected - about 4 hours - and that this says that all the oils aren't volatilized right away. The experiment this suggests is to see how much oil comes off in the first quarter hour, second third and so on to give an idea as to how much you loose from, say, an addition half and hour before knockout.