Grainfather Efficency calculator V Brewers Friend

[DJDave]

Having joined forum noticed the calculators section from Brewers Friend.

Consistently the GF calculated pre boil efficiency is better than Brewers friend. ie last two brews were:


Pre boil 30 litres AG 1.035 efficiency = 91% via GF 84.47 % via BF
Pre boil 29.5 litres AG 1.033 efficiency = 84% via GF 78.22% via BF

Now BF is more detailed in that you can specify the grains used - and therefore is knows that some of grain used is not going to have the sugar potential as the main grain. So in theory I would expect it to produce a more accurate figure. But if I attempt to compare like for like and just enter all grain as maris otter I get a lower figure 76.4 - where I would have expected higher as it knows some grain is just not going to give as much sugar. So I am confused

Is GF just more optimistic?

How does the BF adjust for different grain?

 

[Slid]

Having joined forum noticed the calculators section from Brewers Friend.

Consistently the GF calculated pre boil efficiency is better than Brewers friend. ie last two brews were:


Pre boil 30 litres AG 1.035 efficiency = 91% via GF 84.47 % via BF
Pre boil 29.5 litres AG 1.033 efficiency = 84% via GF 78.22% via BF

Now BF is more detailed in that you can specify the grains used - and therefore is knows that some of grain used is not going to have the sugar potential as the main grain. So in theory I would expect it to produce a more accurate figure. But if I attempt to compare like for like and just enter all grain as maris otter I get a lower figure 76.4 - where I would have expected higher as it knows some grain is just not going to give as much sugar. So I am confused

Is GF just more optimistic?

How does the BF adjust for different grain?

The GF mashing efficiencies are very good, but the 3.5L dead space (think of the formula for the mash water!) tends to make brew-house efficiency a fair bit lower. Just what it is, I suppose with an All in One system.

I did once (only) mess around with the idea of extracting more wort from the gunky trub at the end of the cooling to FV phase, but it wasted far more time and effort than it was worth.

 

[Ghillie]

Having joined forum noticed the calculators section from Brewers Friend.

Consistently the GF calculated pre boil efficiency is better than Brewers friend. ie last two brews were:


Pre boil 30 litres AG 1.035 efficiency = 91% via GF 84.47 % via BF
Pre boil 29.5 litres AG 1.033 efficiency = 84% via GF 78.22% via BF

Now BF is more detailed in that you can specify the grains used - and therefore is knows that some of grain used is not going to have the sugar potential as the main grain. So in theory I would expect it to produce a more accurate figure. But if I attempt to compare like for like and just enter all grain as maris otter I get a lower figure 76.4 - where I would have expected higher as it knows some grain is just not going to give as much sugar. So I am confused

Is GF just more optimistic?

How does the BF adjust for different grain?

@Slid is right, it's not possible for calculators to accurately determine mash efficiency with all-in-one systems. I routinely get 110%+ mash efficiency... There's obviously no need to explain to you why that isn't correct.

BH efficiency is accurate however, and that's the main efficiency value to consider when brewing. Regardless of the value, keeping it steady between brews will help you hit your numbers better.

 

[DJDave]

sorry, I don't follow - I have x Kg grain & y liters of wort of AG z, a potential to extract w sugar from said grain and an actual value of extracted sugar reflected in the AG and the volume of wort, What difference all in one re circulating or pot on a burner? Its the amount of sugar I have extracted versus the possible amount I'm interested in.

 

[Duxuk]

As long as you use only one system to calculate efficiency you'll have a comparative figure for every brew. Surely that's what we're after, rather than some supposedly accurate figure?

 

[Ghillie]

As long as you use only one system to calculate efficiency you'll have a comparative figure for every brew. Surely that's what we're after, rather than some supposedly accurate figure?

I guess so.

The OP mentioned how the two calculators spat out different results. I was merely pointing out that not only are they both wrong, but they're both different. This further demonstrates the problem calcs have with all in one vessels.

 

[PhilBrew]

Hi DJDave

I have x Kg grain & y liters of wort of AG z, a potential to extract w sugar from said grain and an actual value of extracted sugar reflected in the AG and the volume of wort

... certainly that's what "efficiency" is looking to calculate ... but to be honest, I can't work out what you were asking about in your original post. When you said ...

Consistently the GF calculated pre boil efficiency is better than Brewers friend. ie last two brews were:

Pre boil 30 litres AG 1.035 efficiency = 91% via GF 84.47 % via BF
Pre boil 29.5 litres AG 1.033 efficiency = 84% via GF 78.22% via BF

... were you using the brewer's friend and grainfather calculators to predict gravities/mash efficiencies or to calculate mash efficiencies achieved against recipes entered? There are reasons why the calculators might give different answers, but the explanations will differ depending on what you were doing when you noticed the differences

Cheers, PhilB

 

[foxy]

It basically comes down to knowing your SVB, you become part of that system by what your own MO is. How you sparge, the grain, the salt additions, the ratio of liquor to grist, keep trying different techniques to get a consistency and more importantly a great beer. What ever your mash or brew house efficiency will be what it is.

 

[DJDave]

OK, I have a recipe I am reasonably happy with. I am now familiar and consistent ( ****** seals accepted) with the GF operation & I was just curious to know how efficient the conversion is of 4Kg grain & 32 litres liquor into 29.5 litres of wort AG 1.033.

 

[foxy]

OK, I have a recipe I am reasonably happy with. I am now familiar and consistent ( ****** seals accepted) with the GF operation & I was just curious to know how efficient the conversion is of 4Kg grain & 32 litres liquor into 29.5 litres of wort AG 1.033.

OK, if I am understanding this right, you are doughing in to 32 litres with 4 kg of grain, and if what you put down as AG 1,033 should have been OG 1,033 wouldn't be far off, (I haven't crunched the numbers) but just from experience I know the OG wont be high. When going for a fluid mash drop what you think should be the efficiency and set a lower target. If you are using Brewers Friend or Brew smith set the efficiency at 60% for that amount of liquor as a starting point, then increase if need be.

 

[DJDave]

sorry yes Original Gravity. So yes, that is the grain, pre boil volume and OG. & efficiency works out at 84% via GF 78.22% via BF. Why the difference? Well BF will be lower as it knows that some of that grain has less sugar potential.

To compare GF calculation directly with BF I need to tell it the whole grain bill was maris otter and as you would expect it gives an even lower figure of 76.4%.

So back to the original question - why the big difference between the two calculations? is GF simply an over optimistic, perhaps salesman's gloss calculation and BF a bit more realistic?

 

[foxy]

Not something I would be worrying about, it is down to you to find what your own method produces, sparging makes a difference, oversparging brings to the table lower pH. polyphenols and tannins if it isn't done right, but a higher efficiency will be achieved. What works for me is 'no sparge' I don't have to worry about the latter. Your last sentence sums it up, different methods give different results, what you may do will be different to what someone else will do.

 

[PhilBrew]

Hi DJDave

sorry yes Original Gravity. So yes, that is the grain, pre boil volume and OG. & efficiency works out at 84% via GF 78.22% via BF. Why the difference?

... ok, so you're using the calculators to calculate efficiency achieved from that grain bill ... and as you are identifying for yourself, the differences will ultimately be based in the values that the different calculators use for potential extract in their grain databases (what you identified as "w" in your description of efficiency above) ... I don't know those calculators well enough to investigate the values those calculators are using, but you can calculate them based on the results you've provided ... you got 29.5 lts at 1.033 from 4kg of grain ... that's ...

29.5 x 33 /4 = 243 LDK (litres degrees per kilogram) extract achieved​

... and for Brewer's Friend to calculate that as providing an efficiency figure of 78.22%, then they must have assumed a potential extract of ...

243/0.7822 = 311 LDK potential extract​

... while, to get it's figure of 84%, the Grainfather calculator must have assumed a figure of ...

243/0.84 = 290 LDK potential extract​

So back to the original question - why the big difference between the two calculations? is GF simply an over optimistic, perhaps salesman's gloss calculation and BF a bit more realistic?

... hmmm, assessing the motivations of "why" those calculators might have assumed different figures for potential extract is getting into a whole other area ... but a commonly quoted expectation for potential extract from Pale Malt is 36 ppg (or 1.036 ppg if you prefer to write it that way) which equates to 300 LDK, and so those calculators are using figures in a range within +/- 4% of that commonly quoted "average" ... seems to me that those differences are well within the ranges of variability of grains (across crop seasons and different years as well as regional variations)

As I said above, I'm not familiar enough with those calculators to know whether you can see the extract potentials they use ... but most other calculators I've used allow you to add/edit the grain data in the database, and if this matters to you to want to get "right", then perhaps you should hunt out the data sheets from your grain supplier to get the actual potential extracts for the actual batch(es) of grains you are using, and edit the grain data to use those figures ... but I agree with foxy when he says ...

Not something I would be worrying about

... contrary to the way some people on some forums will use it as some sort of indicator of how high they can wee up a wall, efficiency is not a measure worth comparing with other brewers ... unless that brewer is providing you with a recipe, expressed in weights of grains and hops and volume produced, and not telling you a target gravity ... mostly it's a tool for you to use, to help you manage the consistency of your brewing ... and given that, so long as your malt is consistently supplied by a reliable supplier who will aim to manage the consistency of their product, getting the assumption you make for the potential extract you might get out of that grain "right", really isn't that important. The key is to keep using the same figures and using them consistently (which may well mean using the same calculator)

Cheers, PhilB

 

[peebee]

… Now BF is more detailed in that you can specify the grains used - and therefore is knows that some of grain used is not going to have the sugar potential as the main grain. …

What are you using for the predictions*? The Grainfather calculations are very flexible, but if you use the defaults (i.e. do nothing) you will get the "defaults". This from the GF Web based calculator, but the mobile calculators have them too:

The units are a bit "arcane" but there are converters about. This figure shown is for pale malt and probably converted from where I imported the recipe, but you are free to alter it (I don't because I use Beersmith for recipe building).

* Don't forget, they are nothing more than predictions, not some exact science. Even weather forecasting, which is magnitudes nearer to being an exact science, has numerous prediction models which won't agree and may be completely wrong.

 

[Duxuk]

I use an arithmetic method for BHE. It's (295XWeight of grain)/volume of wort=A.
(OG-1)X100,000=B
B/A =BHE
So A might be around 56. If OG is 1.050, B is 5,000. B/A is then 89.3%
Probably very wrong as a figure but as a comparison between every one of my 147 OG brews, it suffices.

 

[DJDave]

thank you all - I was just curious as to why the calculators had different answers and its clear that its the estimate of potential sugar each chooses to make. And people are right it doesn't really matter, I'm happy if my post boil OG is >= 1.040 to end up with a decent session beer of about 4%