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biabacus post boil dilution and laws of physics help

Post #1 made 10 years ago
by Viper5110
Hi Guys

I have attempted the attached brew. Its only my second one and I managed to get 20L of wort into the fermenter at the right OG :thumbs: So happy days but I want to improve

Trouble is at the moment I am using the Biabacus retrospectively. Looking at the numbers it seems impossible so I'm guessing I have something fundamentally wrong (albeit I haven't fine-tuned it for my boil off etc)

Retrospectively to get section K to show my actual numbers I have tinkered with section W. (I.E. I have done this in reverse based on what I saw)

MY strike water was indeed 13.3 L and my Mash volume was approx. 18.13 L . ( this seems to be limit for my pot)
When I lifted the bag this dropped to 8L but then I got about 5L more from the grain bag, so 13L of a predicted 14 ( so-far so good)

I then added more water to the pot (didn't measure it). to fill it before boil (sparged water)

At flame out and post hop sock removal I had 12.8L where biabacus predicts 18.3 (assuming I added 9 or so liters) Of course I didn't add anything like 9 L . Probably more like 6 at the most. Problem is if I change the 9L to 6 my mash goes over my cooker and I boil the house down, (it cant work!)

I would like to know how I can only add 6L to the boil without affecting mash vol etc Im assuming that my boil wasn't as vigorous as Biabacus predicts but it did a rolling boil for 90 mins. I guess I could alter the boil off rate??

I will def measure my added water next time.

Finally I only got 20L to reach my OG. I should also add that I only used the amount of grain from the original recipe so I was never going hit 23L anyway. so fair enough. Biabacus recommended another 2.5kg+ of extra grain and to be honest I just don't think its possible to add nearly 7kg in a 19L pot??



If all the above sounds like the ravings of a madman then its probably because I think I've myself confused now :headhit:
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Post #2 made 10 years ago
by joshua
Viper,

First may I say, making 6 gallons of Wort into the Fermenter from a 5 gallon Kettle, is not going to make very good beer.
Image
It will finish like a poorly made 3V system.
Image
After That, In section W, I would meke a few small Changes, I would go with 3L added before the boil, and added 6.2L during the Boil.
then keep the 7.2L added to the Fermenter, if you need 5.63 Gallons into Packaging.

See attached file....

If you can get a cheap 40L kettle it would work better for this Size Batch.
Last edited by joshua on 18 May 2015, 06:20, edited 1 time in total.
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Post #3 made 10 years ago
by pricelessbrew
I'm not super versed in the biabacus, but I agree with Joshua

The best course of action if you absolutely must get 5 gallons out of the fwrmenter imo would be to maximize your mash volume to be 4.8 gallons, pull the bag, sparge and add the running to get back to 4.8 gallons. Sparge again during the boil and add that back to the boil kettle, keeping the volume near the top of the pot. This should give you the best efficiency in your situation. The only problem I would for see is if youre using undwrmodified base malt or a cheap 2 row/pilsner as the running a wouldn't get boiled for the whole time and so may produce dams..

The alternative would be to go with a slightly smaller batch size, even 4 gallons would be doable with a single sparge and no boil additions.
Last edited by pricelessbrew on 19 May 2015, 07:58, edited 1 time in total.

Post #6 made 10 years ago
by PistolPatch
Viper5110 wrote:I would like to know how I can only add 6L to the boil without affecting mash vol etc Im assuming that my boil wasn't as vigorous as Biabacus predicts but it did a rolling boil for 90 mins. I guess I could alter the boil off rate??
Been out of action for about five weeks so thought I'd see if I haven't lost too much brewing knowledge in that time :).

Viper, the BIABacus does something that no other brewing software is able to do, it looks at your situation and then makes adjustments to suit your situation. For example, in your scenario, as Joshua mentioned, yo are really stretching things to extremes - way too much. Imagine if you had a sieve full of table sugar and poured a cup full of hot water to it. All brewing software, apart from the BIABacus, assumes that you will get that whole cup of sugar 'melted' regardless of how much water you pour over it. The reality though is that how much 'sugar' you get out of your grain bed, depends on many factors but one of the most important ones is how much water you wash the grain with. Hopefully this is obvious when written like this but unfortunately you won't find it written like this except here because other software can't handle the fairly complex calculations that are involved here.

What's happening in your scenario is that you are demanding x amount of sugars for your brew but are not washing your crushed grain with enough water. The BIABacus compensates for this lack of washing by increasing the grain bill. You can quickly get to a stage where the amount of grain you need fills up your small kettle with little increase in the resulting sugars. (Depending on the version of BIABacus you are using, a warning should be thrown up when you get too out of control.)

I'm going to exaggerate what Josh said above... "You can't get 100 litres of beer from a 20 litre kettle by diluting or using more grain etc." That's pretty obvious. But the restrictions are actually much lower than this. In fact too get say x amount of a 1.050 wort into your fermentor, you really would want to be using a kettle with a volume of 2 x x. You can alter this a fair bit, but everything you do will involve some sort of compromise and the law of diminishing returns is very real when you do move away from full-volume brewing.

[Looks like I am still able to write like I used to. What I think will take 5 minutes takes thirty :P]

:peace:
PP

* I think any of my posts with the word "compromise" in them would deal with this. "Sweet Liquor Shop" will also yield info as would a search of "full-volume variations".
Last edited by PistolPatch on 23 May 2015, 21:16, edited 1 time in total.
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Post #7 made 10 years ago
by Viper5110
Thanks for all the replies. I have now bought a 33L boiler and a larger mash bag. Getting 20L of 1.046 wort from a 19L pot was an interesting experience though and It can be done. Nothing wrong with the taste to me but if a full volume version will be an improvement then cant wait.
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