That is cool mike! Very nice!

Refractometers are not so nice. I have one but have retired it. Search my posts for the reasons why.


PP

That is cool

And the reason I can say that I believe it confirmed the theory is because the result was pretty much perfectly predicted

Where as before I didn't even know if my approach was valid. Now, I would like more confirmations but 5 out of 5 is good

Stu, I had no idea you had 5 confirmations. Now that is very cool! .

Really pleased to hear that - good on you .

Yup, but only one so far for the sparge calculations.

But they are based on the same general theory

The biggest question I had was if it was possible to mash at 1.100 SG, which mike has proved

stux wrote:Yup, but only one so far for the sparge calculations.

I might be able to help with this but not until mid-January at the earliest .

I intend to do two side by side double-batches of the same recipe as part of a noi-chill/chill experiment. With double batches, I have to always top up a bit before the boil on doubles so I can sparge one lot and no-sparge the other.

Just sorry I can't do it earlier.

You can tell the calculator how much sparge you want to use. If you don't it will tell you how much top-up to use

I had a play around this morning for an hour or so and got most of it sorted .

I'm still a bit confused on the grains sheet. [In writing the below, I have got most of my questions answered but will leave them in here in case it helps anyone else.]

1. Do the 16.5, 0.25 etc in column H refer to Mike's grain bill in this post? If so, is the 16.5 a typo - shouldn't it be 17.5?

2. If I delete these figures, the Grain Bill on the first sheet doesn't change. Ah, hold on, I now see that I have to change one of the red figures to trigger things. And, of course, get an error. (Tick that question off.)

3. If I want to compare this to the existing calculator which works off an LDK of 307 if I remember rightly, I suppose I can just add a grain called 'The Calculator' and write 307 in column F? (Tick this question off too.)

Do you reckon on the next version it might be cool to have the default grain set up as 100% of 307 LDK so it matches the existing calculator? Have attached a copy here so you see what I mean. The first grain is called 'Default'.

Is there some way of making the first page update automatically when someone changes anything on the grains page?

Donya!
PP

That would've changed the potentials a little bit. The specialty grains with less potential would've been a higher percentage of the grist in the calculations

...

Yes, you could use a "307" LDK grain. The problem is 307 is not actually a very good estimate. In The Calculator there is a fudge factor used called "efficiency" Which compensates for this estimate being perhaps a tad high

In the CE calc there are no fudge factors to fudge a too high estimate. You would need to drop the conversion efficiency from 99% to about 95% to act as a fudge to make the numbers work. But 99% conversion is realistic and does make sense, as the Course Grind conversion should be about 1-1.5% worse than the Fine Grind which is the definition of 100% conversion

Course Grind is 0.7mm, Fine Grind is 0.2mm, at least in the UK and I would expect most BIABS to be somewhere between those two extremes. I am using 0.5mm now.

Having to fudge the numbers by decreasing the conversion efficiency to lower the potential of an artificially too high LDK value would not be ideal.

The 307 value would be a good value, if we treated it as a Dry Basis value, it's basically 80%, but in The Calculator it's used as an As Is value, which means it's circa 4% too strong. Which means all the efficiency calcs in the previous calculators are circa 4% out.

So, continuing to use this value, at least with out adding 4% moisture correction to it, will continue to propagate what I believe is actually an error.

Okay, I'm getting a bit lost again .

I've just spent a few hours on this but don't seem to be getting anywhere .

If I put the following into the CE Calculator..

100% Grist Bill with a derived HWE% of 79.43 [This is what comes up when I put 307 in as the LDK (As Is)]
10 L evaporation
25 L desired fermentor volume
1.050 Original Gravity

the result is 5.057 kg of grain and an EIK of 83.9%

When I put the same numbers into the exisitng BIABrewer,info calculator (or BIABacus Beta) I get 5.659 kgs of grain.

What's going on


PP

If you could actually find grain with an LDK As Is of 307, and you used that, then you would only need 5.057Kg Of grain

As I said previously, 307 is not right. It works out as 79.43% as is

I suspect it's closer to correct as 307 Dry Basis with 4% moisture

This 4% moisture which The Calculator is not handling is being accounted for in the calculator by reducing the expected mash efficiency by 4%

Rather than trying to plug 307 in, try plugging in the actual grain stats and see how far away from 307 that is

I meant to say, I don't have my laptop right now so will check later

But are your losses all the same? Ie kettle loss?

Also you've left Real Absorption at 1.3 right?

Agh! I assumed the CE calculator had the same losses as the BIABrewer calculator . Let's see how I go now...

On the grains sheet,I utilised the empty rows on lines 34-36, to ad in generic grains with an LDK of 307, 307 - 4% and 307 + 4%. I am usiong 10 L evaporation, Desired Volume into Fermentor of 25 L and an OG of 1.050. I will make the BIABrewer Calculator match the CE Calculator's kettle losses of 2 L.

Using 307, CE Calculator gives 5308 grams and 83.3% EIK. BB Calcualtor gives 5279 grams. (A 28 gram difference - bugger all and this would be explained by rounding of decimal points in efficiecny!!)

I won't bother with the +/- 4% of 307. I think you have answered my question Stu

Thanks mate!!!

The 2L value in CE calc is just a constant. Set it to what you think it should be.

Ie probably better to make it match the BIAB calc value

LOL!

Now, have you changed the "Liquor Retained by Grain" figure on me as well?

From memory, in the Calculator, we have 0.628 L/Kg.


PP

That figure is 'apparent'

The ce calc uses 'real' absorption

Leave it as 1.3 until youve done five brews

(actually an average of two should be enough, it seems to vary between 1.2 and 1.4 based on perhaps your grind and how vigorously you squeeze).

Unfortunately, for some reason, I have been landed with the job of understanding all the formulas used in the BIABacus. I have been trying to resign for months but all my resignation emails/PM's seem to be ignored .

I've got to tell you that it is not easy. Nearly every day requires way too many hours of investigation, reading, writing, communications etc. It's way too much work but if you drop the ball for a few days you pay a high price.

So, help me out here (again) please Stu

I have no idea what 'real absorption' means. All I know is that with "The Calculator," I collected a lot of BIAB brewer's figures and came up with the average that for any kilogram of grain in a brew, 628 ml of liquor will never see the kettle.

I understand/know this. The figure might be wrong but until we ask more brewers to give us figures, it's the best we have and I think it is the one that we should all use.

WTF does 1.3 actually mean ?

LOL!
PP

Okay,

Apparent absorption is the absorption you apparently see, ie I added 35L of water and 5KG of grain and I end up with 32L so I lost 3L to 5KG of grain. Ie 0.6L/KG

The thing to realize is you had 20L of water but you gained 4KG of extract OUT of the grain and then the grain absorbed liquid

Real Absorption is how much liquid the grain really absorbed. Apparent is how much it appeared to absorb.

The difference is you're not counting the additional volume you acquired from the sugars you extracted from the grain

The reason it's important is because apparent absorption changes with gravity (I think), while real does not!

1.2-1.4L of liquid is *really* absorbed by 1KG of grain in BIAB. That 1KG will give you about 800g of extract. That 800g will contribute about 500ml of extra volume, which is the difference between apparent and real absorption.

Sorta

Seriously, try leaving it as 1.3L/KG for now

It is based on the physical properties of dry grain

You guys are making my brain hurt.

(But your efforts are greatly appreciated!)

Good Day Sigurdur, Grain absorption is important to those of us who use 20 or more Kg of grain in BIG batches. It is impotant how to lower that amount to a minimum in real brewing!!

I think it may make a bigger difference in the sparge calcs

Good Day Sigurdur, I understand what you say about "apparent" absorbtion and "actual". I see that I start with a volume of water@1.000sg, and a volume of grain KG, I have measured a loss of grain weight, with a slight loss of volume of water@1.033sg, The calculation interests me to explain the weight of sugars removed from the grains, and the remaining water. It helps to know how much water should remain in the grains, so I can try to get that, not much more.

stux wrote:Seriously, try leaving it as 1.3L/KG for now

Okay.

I'm thinking this means I won't have to think about it (maybe in the new year) which sounds like a great Christmas present. Thanks mate!

thughes wrote:You guys are making my brain hurt.

I'm hearing you brother .

Hope all you guys will be putting your feet up over the next few days. Take it easy and all the best!

The idea is to make a calculator which requires very little tweaking.

In my research (using biabrewer historical figures too) I've found real absorption to be between 1.2 and 1.4

1.3 is a good value because if you actually have more absorption you get slightly less beer at higher gravity at the end and can correct with a little bit of water. If you get slightly less absorption you end up with more beer and possibly a little bit under gravity (due to constant evaporation)

If you used 1.4 and you got 1.2 then you would miss your OG fairly significantly. And if you got 1.4 instead of 1.2 you would also miss, but your efficiency would be down.

Hence 1.3 is a good value, and the idea is a new brewer doesn't have to change it. After the brew the calculator does display your achieved real absorption

Internally everything is worked out using real absorption, it is a fairly important metric, but my theory is that it doesn't actually vary that much. What varies is grain potentials and conversion efficiency, and that affects apparent absorption