Beer Calculus V Beersmith

[Scruffy]

So I bought some Maris Otter (7.5KG) and a bit of Crystal (.5KG) and I'm trying different hop schedules with 90gms Challenger and 90gms Citra. FWIW I'll be using that new Thames Valley stuff (1882PC)...

Anyroad...

I'm tapping various schedules into Beersmith and seem happy with a regime that gives me 60IBU ... slightly distracted, I'm surfing the information superhigh... sorry typing stuff into Google's and come across Beer Calculus: the same schedule yields only 37IBU's

Question is, why the discrepancy?

-Edit- it's worse the other way - i try for the 60IBU in Beer Calculus, get it (after adding 20gms extra Nelson @ 60!) and type the numbers into beersmith - 45gms Citra and 30gms Challenger (@ 60) and I'm already on 67IBU!!

From experience, I'd tend towards Beersmith...

 

[RdeVjun]

I'd guess it may be a function of bitterness methodology, i.e. Tinseth, Rager, Garetz etc. Depending on which which method your app is using, calculated IBU will vary, particularly <1.050 where Rager would generally be advised.

See Promash's FAQs, Q3, there may be something similar for Beersmith, I'd be surprised if there wasn't.

 

[Scruffy]

...yup, food for thought!

However both spreadsheets are set to use the Tinseth equation. Both have very similar potential grain values, both have the same Alpha values (can't set beta on BC though), both assume all grain, both set to hop pellets - what i'm not sure what is assumed about wort density boiling in BC, Beersmith knows i have a shitty BIAB rig, and i boil the shit out of it!!!
Just surprises me that there's such a difference, and after I had tried to match all the usual/known variants... then again, i don't profess to know everything...

The proof will be in the drinking (which I'm hoping will be around 15...!)

 

[newguy]

I'm leery of beersmith. A friend and I collaborated and brewed a ridiculously hoppy IIPA and my old version of SUDS came up with 101 IBU and his beersmith said 250. Now given that it's well known that ~100 IBU is the solubility limit, I'm rather impressed that SUDS took that into account.

Take this opinion with a grain of salt as I've never used beersmith myself - I'm speaking solely on this IBU issue.

 

[katzke]

Most likely a difference in how each program calculates wort volume.

 

[Fourstar]

Most likely a difference in how each program calculates wort volume.

Yeah, i was thinking this in relation to expected boil OG too.

Are the programs matching your expected FG's and the boil volumes are the same?

 

[Scruffy]

Yeah, i was thinking this in relation to expected boil OG too.

Are the programs matching your expected FG's and the boil volumes are the same?

I'll let you know Mr 4*, sir! In the past they've been adequately ball park, though going back to Mr newguy's suggestion that Beersmith may be a touch generous with its predictions, I have a feeling he's pretty much on the money... the last few brews I've made could have been perceived as light on the old hop...

A controlled experiment might be prudent...

Now where can I get about 8 kilos of Maris Otter from... oh wait...

 

[chris.taylor.98]

Beersmith is using a fairly faithful implementation of the hop bitterness utilisation methods. Here are some more details:
http://www.beersmith.com/Help/estimating_bitterness_tech.htm

I have implement both Rager and Tinseth in Brewtoolz and get similar results.

Here is another good source of reference for hop utilisation modeling http://www.realbeer.com/hops/FAQ.html

From reading this I would say Beer Calculus is using something like Garetz method, which is considered the most pessimistic of the three methods.

newguy makes a good point that sometimes these formula give unrealistic results, so you need to take common sense into account too.


Generally speaking Rager is considered to be on the optimistic side and tends to better suit extract brewing, and Tinseth is better suited for all-grain brewing.

You have to keep in mind that these are just models and they may or may not suit your brewery and or ingredients. Hop utilisation is one of those areas is very hard for us as homebrewers to accurately gauge, so it can be difficult to ascertain which tool is the most accurate without sending of samples to a lab to verify.

Note Melbourne Brewers are planning on doing a hop experiment this year to do just that.

As with all things homebrew if it works for you it works for you. If you find a tool and or method that gives you what you want then probably best to stick to it.

 

[Scruffy]

Very nicely put. Can I just say I'm very happy with Beersmith, and as mentioned, I need to get my own kit in order before pointing the finger anywhere else... and maybe if you're going to throw 180g of hop in a brew, you can't beat a bit of experienced advice.