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Gill wrote:Ha, no, but I'd throw a few more in and see how 15mins went

I'm not a Hops expert , but I don't think 15 minutes wouldn't be long enough to add bittering qualities.

BeerSmith should be able to calculate it all for you. You'll just need to fiddle around a bit to allow for the 8-litre boil but 23-litre (or whatever) final volume.

Got that far, but I can't tell it I will add the extract afterwards.
I can remove the extract from the recipe, look at the IBU, then add it back in. Is that an accurate reading on what my IBU will be or does that affect a few factors at once by removing it?

Gill wrote:
Got that far, but I can't tell it I will add the extract afterwards.
I can remove the extract from the recipe, look at the IBU, then add it back in. Is that an accurate reading on what my IBU will be or does that affect a few factors at once by removing it?

That would probably work, but you don't need to do that. When you add an item to the recipe, you should see a tick box for "add after boil". Beersmith then adjusts your boil hop utilisation to take the reduced boil gravity into account account.

You'll also see a field called "late extract boil time", in which you can enter the actual time you paln to boil the extract. Note that Beersmith does not take this figure into account when calculating hop utilisation, so it is really just for your records. In BS1, the tick boxes for "late extract boil" and "add after boil" are mutually exclusive (ticking one unticks the other). In BS2, you can tick the "add after boil" box and still enter a "late extract boil time", although this has no effect on the IBU calculation.

At any rate, I would add the extract 4 or 5 mins before the end of the boil, to ensure that it's well disolved and that no bugs survive (less of a concern if it's a freshly opened can).

Ah, thanks squirt.
Alright, I'm quietly confident now, ordered the ingredients.

If it doesn't work it surely doesn't reflect on my inexperience and barely adequate equipment, I'll just blame bad advice from those guys at the forum

Two kilos of grain and one kilo of rice in 8 litres will be quite higher than 1.040 which is why I suggested multiple boils. Do you have more than one pot? You can do two (or even three) boils on a stove simultaneously and add your extract for the last few minutes of the non-hopped one to sterilise it. The second boil doesn't need to go longer than 10-15 minutes so you can be cooling that one whilst the hopped boil is still going. I did a lot of multi-boils before I got my urn and they always worked well.

So I would only hop one of the boils?
I was going to split it between the boils

Nah, just throw your whole amount of hops into the boil you make to 1.040. There is some discussion as to boil size affecting hop utilisation but I never had any problems and I was doing 10L boils.

bullfrog wrote:Nah, just throw your whole amount of hops into the boil you make to 1.040. There is some discussion as to boil size affecting hop utilisation but I never had any problems and I was doing 10L boils.

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BUT, unless I'm mis-reading this!! I still think that Bullfrog suggests to halve the amount of hops between the boils or1/2 of the initial volume!

Yup, misreading it, haha. What I'm saying is to do a boil of 1.040 wort into which you make all of your hop additions. At 1.040 you get better utilisation than if you had a higher SG wort so you don't need to increase your hop quantities to compensate.

Then, in a different pot, you can boil the rest of your wort to sanitise it then it all gets mixed together in the fermenter.

Think of it as making your own kit (wort with a high concentration of hops) then adding your other fermentables.

Okay then, will do.

But quick question:
If this is effective, why don't people just boil up hops in straight water with an SG of 1000 and add that to the fermenter?

Gill wrote:Okay then, will do.

But quick question:
If this is effective, why don't people just boil up hops in straight water with an SG of 1000 and add that to the fermenter?

This is an often debated issue, Gill, and one that seems to have an obvious answer (lower gravity = better utilisation, therefore pure H2O must give best utilisation). However, those alpha acids do strange things when they're boiled, and actually require some of the compunds found in wort in order to be most effectively isomerised. 1.040 is reputedly the "sweet spot". The Rager formula on the graph you posted is more accurate than the Tinseth in this regard.

I did a quick bit of Googling, but only found forum threads with similar questions to this one. I do recall reading an article (buggered if I can remember where though ) in which some sciency types had boiled hops in worts of varying concentrations (starting with plain water) and measured the isomeriation, and the results pretty much confirmed the 1.040 SG theory.

Palmer doesn't seem to shed much light on the subject either.

We have finally put down the recipe tonight. Not too many hiccups, the mash temp dropped from about 66 to 63 in 25 mins, so I added more hot water to 67, it then fell again to around 62 about 10 mins before the end and I raised it again to 67. (I just followed TL's mini mash in an esky method, but swapped it around a bit to do BIAB).

The boil is bubbling away as we speak, 45 mins to go. Overall quite happy I think, should the drop in temp have caused any noticable issues (to me at this point)?

Thanks for the advice everyone.