dimentions of your kettle vs hop aroma

[Dan]

I was reading somthing about scaling down commercial size batches when i came across this.

"The hard thing about scalling up or down is hopping. The list of reasons includes lower surface to volume ratio in large kettles, more vigorous boils in larger kettles and lower surface to volume ration in the ferementer.
The key here is surface to volume ratio and the idea that hop acids and oils stick to the surface. The more surface to volume wort the more loss you get with hops. this same thing occors in the fermenter when the foam from fermentation is yet another surface that scrubs hop goodies from beer."

"as batch size decreases hop oils are harder to keep in the wort where they are needed if the beer is to have a nice hoppy aroma"

"the hop oil loss is not so easy to balance, because when you add more hops to make up for the oil loss you add bittering acids and plant matter that can begin to add a vegetal flavour to beer when heavy hopping rates are used.

(excerpts are taken from BYO columist Aston Lewis' book "home brewers answer book")

can anyone with a tall brupacks ketlle confirm this ?

[Dan]

on my current squat cartering pan i have a surface area to volume ratio of approximately 51cm2 per litre

the nordic optical pan I just bought 70L 45cmx45cm has a ratio of around 26.5 cm2 per litre (when filled to 60L)

and the larger 100L nordic pan 50x50 should have a ratio of 21.8 cm2 per litre (when filled to 90l)

The brupaks tall 75L gets 16.1 cm2/L at 65l
and brupaks tall 100L gets 14.6 cm2/L at 90l

a micro brewery sized boiler like the brupaks 1000L might get a ratio of 7.4 cm2/L when 90% full

[Vossy1]

I'll be interested in the anwers to the questions above.

At least moving from 70 ltr pots to 100 ltr pots I'm heading in the right direction

[Vossy1]

bump

[Stonechat]

this same thing occors in the fermenter when the foam from fermentation is yet another surface that scrubs hop goodies from beer."

I like to use fermenting buckets with a greater circumference at the top than the bottom, as I use a vigorous top-fermenting yeast. I thought that the greater surface area you give a yeast like this the quicker and more effectively it can do its job.
Am I wrong? Advice please.

[Duncndisorderly]

is that Valhalla? surely a full grown man (fully cleaned and scrubbed) could bathe in such a large beer tank

[anomalous_result]

Ringwood open FVs iirc.

[Stonechat]

Don't know what the "iirc" stands for, but is AR right in saying that these are the open FVs of the Ringwood Brewery?
When I posted earlier today I was going to mention the Yorkshire Squares that have a huge surface area, but did not want to muddy the water, as I think that type of yeast is not a strong top fermenter and needs a lot of rousing.
Ringwood beers taste good so they have not suffered from being fermented with such a large surface area for the yeast to top-ferment in.

[Stonechat]

Now that is what I call yeast with attitude

[Stonechat]

That is the yeast's way of telling you it wants to be doing its stuff in an open FV.

[WallyBrew]

and the larger 100L nordic pan 50x50 should have a ratio of 21.8 cm2 per litre (when filled to 90l)

Cannot help but think there is something wrong with the maths here. The figure of 21.8 seems to be derived from the area of the base without taking account of the sides. Should it not be ((25 X 25 X pi) + (50 x pi X 45))/90 = 100.3 for 90 litres in a 100 litre stock pot.

Don't know the dimensions of a brewpak or other boiler.

Feel free to shoot me down

[Stonechat]

Daab, may I ask what the thinking is behind your choice of King Keg as an FV?

[anomalous_result]

Don't know what the "iirc" stands for

Just for clarification it's shorthand for 'if I recall correctly'.

[Stonechat]

Thanks for that. I thought it might have been something to do with the plastic of the KK being opaque and cutting some of the light out.
I use the Hambleton Bard buckets with sloping sides, as I wanted a bigger surface area for the top-fermenting yeast to work on. Sometimes it climbs right over the top from the 26 litre mark, but it's worth the clearing up as it does 90% of its work in the first 3 days.

[Stonechat]

Don't know what the "iirc" stands for

Just for clarification it's shorthand for 'if I recall correctly'.

Thanks for that. I've made a note of it.