First extract brew Qs:hop utilisation & Safale+high OG

[drf]

Planning my first extract brew and a couple more questions. I will be forced to do a reduced volume boil given the equipment I have. I'm aware of advice to increase the amount of hops due to a decreased hop utilisation in higher gravity boils. Graham Wheeler's book talks about the decrease in hop utilisation in increased gravity boils being due to protein, rather than sugar content, and that if using malt extract this is less likely to be an issue. What are peoples' experiences here - is it always worth adjusted hop amount for a reduced volume boil? Also, would the situation be any different if using other malts e.g. crystal/chocolate as well.

Secondly, I'm considering a highish OG brew (1.070). Is Safale-04 going to be OK with that if used dried? Better to rehydrate? Or a starter? Or more dried yeast? I'd anticipate a maximum volume of 10 L so I'd be over pitching anyway. Any benefit of adding yeast nutrients?

Cheers

Chris

 

[alanywiseman.]

I am by no means an expert but I have been readin up on hop utalisation and shorter boil volumes as i am wanting to move to extract. My understanding is that, as you have said, it is the protiens, not the sugars, that affect the hop utilisation. This will only have a real affect though when you are working with fixed volumes.

So if you have a brew length of 10L and a boil of 5L with a target OG of 1.040 then during the boil you will have a OG of 1.080. If you were to instead do a 10L boil then your OG would be 1.040 right from the start.

I said that it is the protien that affect the hop utilisation. what the above shows that once you have dilutied your concentrated wort your gravity is the same as boiling the full volume. It is the same princpal when applied to the concentration of protiens and therefore your hop utilisation. You wil have double the concenration of protien in a boil of 5L but when diluted it will equal that of a full boil.

Does that make sense? :hmm:

The hop utilisation is affected when the volumes are kept constant because if the concetration of protiens chages so to will the hop utilisation.

 

[drf]

your concentrated wort your gravity is the same as boiling the full volume. It is the same princpal when applied to the concentration of protiens and therefore your hop utilisation. You wil have double the concenration of protien in a boil of 5L but when diluted it will equal that of a full boil.

Well, yes but the hop utilisation occurs during the boil, so if you have more concentrated proteins the utilisation will be lower. What I was actually wondering is whether protein-related decreases in hop utilisation are only really an issue when doing AG brewing where more proteins will be present from the mash.

 

[alanywiseman.]

I was not clear in the slightest in my last post. It all makes complete sense in my head but I am finding it hard to put into wards so I have borrowed this from another forum but it gets what I am trying to say across much more clearly.

'Hop utilisation, when it comes to what we call the gravity factor, is a function of protein absorbing bitterness in the wort. A fixed amount of grist will have a fixed amount of protein and it will absorb a fixed amount of alpha acid. It matters not, with say 4 kilograms of grist, whether one is brewing ten litres at at 1070, or twenty litres at 1035, the absorption will be just the same; the utilisation will be just the same ; utilisation in that respect is independent of gravity.

However, the confusion arises because twenty-three litres of a 1080 beer requires twice as much grist as twenty-three litres of a a 1040 beer. Twice the grist will have twice the protein and will therefore absorb twice as much bitterness; so hop utilisation is affected by gravity at a fixed volume.'

With respect to extract brewing it is not something that you need to worry about unless you are planning on brewing a beer close to saturation level (supposedly 120 EBU).

(Apologies to Mods if borrowing answers from different forums is not allowed. If that is the case please delete my reply)

 

[drf]

I was not clear in the slightest in my last post. It all makes complete sense in my head but I am finding it hard to put into wards so I have borrowed this from another forum but it gets what I am trying to say across much more clearly.

Ah, I see what you mean now. Yes that's obvious to me. So what I'm interested in is this bit....

With respect to extract brewing it is not something that you need to worry about unless you are planning on brewing a beer close to saturation level (supposedly 120 EBU).

So if the bulk of my wort is made of malt extract I probably don't need to worry about a decrease in hop utilisation

 

[alanywiseman.]

No it is not something that you need to worry about. :thumb:

Good luck with brew when it comes :