Small Boil Hop Schedules - IBU Calc Discrepancies

[Pickaxe]

Hey Fellas,

Just planning to put a Pale Ale down today, haven't used Galaxy Hops to bitter before and with the high AA%, I don't wanna go too over the top.

I'm planning a 25L batch, but can only boil in a 5L pot. Using Ian's Spreadsheet and Beersmith to adjust for the small boil volume, there's a fairly big discrepancy in IBUs I'm going to be getting with the same amount of hops at same boil size.

Hops Ian's Sheet Beersmith
Galaxy
30@60min 23.54 IBUs 18.4
20@15min 7.79 1.2
30@0min -- --

This adds to a fairly significant difference in the end result.

Which should I go for, or can I expect something in the middle ground of these 2?

Any advice?

Thanks in advance.

 

[bum]

There are different sets of calculations that can be used to calculate IBU - they each produce different answers for the same figures.

Dunno about the spreadsheet but there are also ways you might configure BeerSmith that may change how accurate the figures might be for your system.

If you've used either in similar circumstances before (i.e. same boil and batch size) and been happy with the results then just follow that set-up then adjust for the next one if required.

 

[Pickaxe]

Thanks bum.
Yeah, I'm finding Beersmith a little complicated so far, lots of little extra calculations and numbers to fill in. I'm trying not to let it overwhelm, because its not relevant to my level. That's why I compare to Ians Spreadsheet.

Just found another question asked here before, that kind of hit this territory.

Some suggestions that Ians spreadsheet was good at IBU Calc 10L + boils. Looks like going to Big W and buying a $19 pot is a good solution, and its about time i did, so that'll take the mystery out I reckon.

Bout time I bloody got the pot anyway.


{Off topic - I found a 19L cylindrical cooler at BCF for $50. Next month I'll be saving for that and a tap conversion to start getting my teeth into partials and small AG batches.}

 

[Pickaxe]

This is my recipe:


Amount

Item

Type

% or IBU

1.50 kg

Light Dry Extract (15.8 EBC)

Dry Extract

42.9 %

1.50 kg

Pale Liquid Extract (15.8 EBC)

Extract

42.9 %

0.50 kg

Pale Malt, Maris Otter (5.9 EBC)

Grain - Mini mash

14.3 %

20.00 gm

Galaxy [14.90%] (60 min)

Hops

18.2 IBU

10.00 gm

Galaxy [14.90%] (20 min)

Hops

2.3 IBU

10.00 gm

Galaxy [14.90%] (15 min)

Hops

0.9 IBU

20.00 gm

Galaxy [14.90%] (0 min)

Hops

-

With a 10L Boil I'm either gonna get
Ians - 30.8 IBUs
Beersmith - 21.4 IBUs

I like em lighter on the bittering, and big flavour and aroma. I guess I'll know in 6 weeks or so how this has gone.

Very confusing the difference for a noob.

 

[bum]

At the end of the day, neither calc will be entirely correct and you'll almost certainly never get your beer tested to find out anyway. IBU calculation is something of a black art/stab in the dark. It is best to just pick one calculation method and try to stick with it so you work out how the numbers taste in your brewery.

Hard to read your recipe but it looks like you're going backwards from what I'd do for that style of beer. I'd be looking to get most of my IBUs from the late additions rather than the early additions - especially with galaxy. I'd also be looking at getting a bit of spec grain in there for a little depth - the MO will definitely lift it over a straight extract brew in any case. That's all firmly in the realms of IMO, of course.

 

[technobabble66]

Same prob as you, pickaxe

I'm trying to devise a partial mini-mash type IPA-ish thing w lots of late (0 min) hopping, & struggling as a noob to work out: am i gonna end up w floral water or IPECAC.
I'm tempted to do as bum suggested - v little hops at 60min, truckloads at 0min. I read on MrMalty that the late additions can add moderate bitterness - about 30% of normal (god knows what normal is though?? - IBU from a 30min boil?)

How are you doing your mini-mash schedule?? I've been filling my head with rest temps & times - it's a lot for what might be just 2kg grain ...

 

[bum]

For a partial I would pretty much only consider doing a single infusion mash (one temp for the whole time). In fact, I'd fairly strongly recommend single infusions mashes for early full-AG ( h34r: ) batches if you end up going down that road. Steps are something to play with when you've got your system properly dialled in.

 

[ianh]

The spreadsheet has two calculations, without the HCF and with it.

Without uses Tinseth's Calculations which can be found here. http://realbeer.com/hops/research.html This is how IBU's are normally calculated and you can enter your numbers into an online calculator.

The reason for the second method, is kit and extract brewers sometimes boil very small volumes (all grain brewers normally boil the full volume) so to allow for this I used the Garetz method which incorporates a volume factor (HCF). The best that can be said for this method is it provides a guide show you can compare brews.

What I advocate is that you try and boil a minimum of 10 litres and don't use the HCF.

I also think you have something set up wrong in Beersmith.

See you are doing a partial mini mash. I would have steeped some light crystal, carapils or something similar instead.

edit spelling

 

[Nick JD]

Beersmoth getting 1.2 IBUs from 20g of Galaxy being boiled for 15 minutes is bollocks. Even Ian's sheet is too low.

Add to this a slow cooling period, and it's up in the 30s.

 

[bum]

He hasn't mentioned his boil gravity.

 

[Pickaxe]

1.040 boil gravity minimum. 10L.

@ Ianh, I really am overwhelmed with Beersmith and you could well be right. It's not adding up. It's too much for me right now, but I find the spreadsheet wont allow me to incorporate mini mashes. I've wondered about sticking to spec grains, but I'm doing little mini mashes to get me primed for Partials/AG.
Thanks for the help with the spreadsheet. Will go 10L with HCF off.

@ bum, I've seen a few recipes that only rely on late Galaxy additions. Thanks for the tip, might rethink my hop schedule. Appreciate the advice.

@ technobabble66 - mini mash at 66 degrees for an hour or so. Straight in for a boil after - no rests and all that ********. K.I.S.S. is my advice, this is why I am only doing little mashes for the time being. Get a single right a few times, then I might stuff around, but I've made a mistake or 2 on my first. Training wheels for me...
Next month I'm gonna attack a Partial where half my sugars come from mash, gives me room to adjust with extract for mistakes etc...

Cheers for the advice. Keep it coming - I am a beer making sponge.

 

[Pickaxe]

@ bum - I see what you mean.

Using Ians Spreadsheet:
20 @ 20
20 @ 15
30 @ 0
29.8 IBUs.

Your advice is the best - how do I know what IBUs mean unless I establish a standard in my own home-brewery with equipment, batch, boil sizes etc.

Often the simplest advice is the best, and you often have that. Cheers.

 

[Pickaxe]

Unto the breach my friends.
Boil time has come.
Gonna try this:

10g @ 60
20 @ 20
20 @ 15
30 @ 0.

Come what may...