Dry Hopping During Diacetyl Rest

[losp]

Hi all,
I mis-judged the amount of hops i put into the brew. I hadn't realized that hop flowers weigh about 1/6 of the pellets!
So now i am thinking about dry hopping which i haven't done before.
From a lot of the recipes that i have read people seem to dry hop in the last 3 days or so of fermenting. (is there a reason for this?)
If i do this it will run during the same time as my diacetyl rest. Does this interfere in any way or perhaps produce off or funky flavours?
Cheers,
Aaron

 

[newguy]

Some people only dry hop for a few days, some more. I tend to let my dry hops sit in the fermenter for the last 1-2 weeks before kegging. I find that's about the amount of time for them to sink to the bottom which makes racking easier.

Edit: Forgot to add that no off flavours will be produced by what you propose.

 

[Hutch]

Hi all,
I mis-judged the amount of hops i put into the brew. I hadn't realized that hop flowers weigh about 1/6 of the pellets!
So now i am thinking about dry hopping which i haven't done before.
From a lot of the recipes that i have read people seem to dry hop in the last 3 days or so of fermenting. (is there a reason for this?)
If i do this it will run during the same time as my diacetyl rest. Does this interfere in any way or perhaps produce off or funky flavours?
Cheers,
Aaron

Not sure what you mean by flowers weighing 1/6 of pellets? I presume you must be refering to hop utilisation in the boil?
Either way, this will only affect bittering, and you would usually use 10-15% less pellets than hop flowers for bittering to a specific IBU.
Dry-hopping is not going to contribute bitterness, only "dry hop" aroma, which lends a sort of resiny grassy aroma often present in big IPA's and some APA's.
I'd advise you only do this if that's what you want to contribute to your beer. It's a lot more "in your face" than kettle hops, and is not to everyone's taste.
Hope this helps.

 

[Scruffy]

What are you brewing? What hops? What Yeast?
You don't want to add your dry hops too soon, i.e. during a primary fermentation, because any 'active' fermentation will vent off any aroma because of the CO2 being produced.

 

[Pete2501]

Not sure what you mean by flowers weighing 1/6 of pellets? I presume you must be refering to hop utilisation in the boil?
Either way, this will only affect bittering, and you would usually use 10-15% less pellets than hop flowers for bittering to a specific IBU.
Dry-hopping is not going to contribute bitterness, only "dry hop" aroma, which lends a sort of resiny grassy aroma often present in big IPA's and some APA's.
I'd advise you only do this if that's what you want to contribute to your beer. It's a lot more "in your face" than kettle hops, and is not to everyone's taste.
Hope this helps.

I think the OP is talking about the weight of hop flowers wet vs dry. Otherwise I've got nothing. Can someone advise the percentage of hop oil vs water content of wet hops?

edit: I thought I'd come back to this.

After a little research I'm pretty sure the OP is talking about the IBUs by weight.

http://www.brew365.com/technique_wet_hop.php

An equivalent weight of dried hops imparts about six times the IBU of a fresh, non-dried hop of the same variety. So, let's say you have grown some cascade hops in your back yard, they seem ready, and you are ready to throw some in your Pale Ale. First thing you will need to know is the AAU% of your hop. Well, that's not easy without lab analysis. No worry, just take the medium range of the hop variety to get an idea. Since cascade is in the 4 to 8% range generally, we will take the average ((4+8)/2=6). Ok, so 6% is roughly what we will say our AAU is. Now, divide this number by six (because the ratio of fresh/dried AAU is 6:1). That gets us down to 1 AAU%

With that said you're not going to get more IBUs from dry hopping. Dry hopping releases more hop aroma into your beer. The IBUs aren't added unless heat is applied.

Also check out this link which goes into utilization as a function of boil gravity and time. There's a graph you can use to apply the above calculation of IBUs you added to your wort and you should come out with an accurate IBU reading.

 

[Scruffy]

I can tell you for a fact that at sea level, on the same planet, 6 grams of dry hop flowers (bless!) will weigh the same as 6 grams of bleedin anything...
Does the OP care to elucidate?

as for % of hop oils in hops, by wet hop do you mean the one still attached to the vine, or one immersed in boiling wort?

Dry hopping won't bitter your brew... only add aroma... no need to worry about AA per se, 'cept that the higher it says it is on the pack, the more intense the aroma (very loosely).

Edit - I see you added lots of complicated stuff! Very good. :icon_cheers: Though you can get pretty bogged down with EVERY variable in Hop chemistry, did you take water composition into account, what farm was the hop from and don't forget your bottle cap liners - they absorb hydrocarbons and longer chain ketones and esters, but not the hop oils. Think about acid hydrolysis...

Your bitterness is relatively easy to calculate, Enter Beer Volume, specific gravity of wort, mass of hops added, Alpha acid rating and Time hops were boiled. The aroma and flavours are much more difficult to quantify...

 

[Scruffy]

...using capillary gas chromatography, boffins have detected and identified more than 250 essential oil components in hops. Twenty two of these have been pinpointed as being good indicators of hoppiness potential. They are subdivided into 3 groups, humulene and caryophyllene oxidative products, floral/estery compounds, and citrus/piney compounds, as listed below:

Oxidation Products:
caryolan-1-ol
caryophyllene oxide
humulene diepoxide a
humulene diepoxide b
humulene diepoxide c
humulene epoxide I
humulene epoxide II
humulene epoxide III
humulenol II
humulol

Floral/Estery Compounds:
geraniol
geranyl acetate
geranyl isobutyrate
linalool

Citrus/Piney Compounds:
delta-cadinene
gamma-cadinene
citral
limonene
limonene-10-ol
alpha-muurolene
nerol
beta-selenene

Try entering that into Beersmith...

 

[QldKev]

Hi all,
I mis-judged the amount of hops i put into the brew. I hadn't realized that hop flowers weigh about 1/6 of the pellets!
So now i am thinking about dry hopping which i haven't done before.
From a lot of the recipes that i have read people seem to dry hop in the last 3 days or so of fermenting. (is there a reason for this?)
If i do this it will run during the same time as my diacetyl rest. Does this interfere in any way or perhaps produce off or funky flavours?
Cheers,
Aaron

So do I need a set of hop scales that have a button for when I'm measuring hop flowers? Wow man I want what ever you are on :blink: :beer:

QldKev

 

[Nick JD]

I don't think the OP is weighing his hops. Although the bag the flowers come in should be an indication of their weight:volume difference...

 

[Bribie G]

One thing that I do - and in fact I'm doing it right now with a Timmy Taylor Landlord wannabee - is to pack one of these with hop flowers or a hop plug and chuck it into the fermenter about four days before racking to a cube for chilling. The OP should have no problems just extending the diacetyl rest by a couple more days.

I see the sponsor is currently out of them, but they can also be found in kitchen shops and some Asian stores.

 

[Pete2501]

Hi all,
I mis-judged the amount of hops i put into the brew. I hadn't realized that hop flowers weigh about 1/6 of the pellets!
So now i am thinking about dry hopping which i haven't done before.
From a lot of the recipes that i have read people seem to dry hop in the last 3 days or so of fermenting. (is there a reason for this?)
If i do this it will run during the same time as my diacetyl rest. Does this interfere in any way or perhaps produce off or funky flavours?
Cheers,
Aaron

What was your recipe?

@BribieG - Yeah my other half has a bunch for making cups of tea with leaf tea.

Edit: Spelling

 

[losp]

I can tell you for a fact that at sea level, on the same planet, 6 grams of dry hop flowers (bless!) will weigh the same as 6 grams of bleedin anything...
Does the OP care to elucidate?

as for % of hop oils in hops, by wet hop do you mean the one still attached to the vine, or one immersed in boiling wort?

Dry hopping won't bitter your brew... only add aroma... no need to worry about AA per se, 'cept that the higher it says it is on the pack, the more intense the aroma (very loosely).

Edit - I see you added lots of complicated stuff! Very good. :icon_cheers: Though you can get pretty bogged down with EVERY variable in Hop chemistry, did you take water composition into account, what farm was the hop from and don't forget your bottle cap liners - they absorb hydrocarbons and longer chain ketones and esters, but not the hop oils. Think about acid hydrolysis...

Your bitterness is relatively easy to calculate, Enter Beer Volume, specific gravity of wort, mass of hops added, Alpha acid rating and Time hops were boiled. The aroma and flavours are much more difficult to quantify...

Since you are being a smart arse i can tell you that grams are a measurement of mass not weight.

I never mentioned anything about IBU or bitterness.

My question about interferance with diacetyl rest has been answered. Thank you all!

About the 1/6 thing, I think i must have misunderstood something else i read on the interweb. Sorry for the confusion.

Losp.