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Goat

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I must have read the help file on Target volumes 10 times and I still don't understand it...

can anyone explain the difference between "Water Needed Pre-Boil Targets" and "Raw Pre-Boil targets" in words of less that 3 syllables?

I am having a blonde moment here I know, but I'm about to pop a vein... !

The window is under Efficiency in the Brew session window - this is the text from the help file

Note that there are 3 targets:

1) The first is the Water Needed Pre-Boil Targets. This is the total volume of wort that is shown "Into Kettle" from your Water Needed Calculator. This combines evaporation rate and boil time plus sparge water, mash water (including additional infusions), vessel losses and top-up water recorded in the Water Needed Calculator. This may vary from the "Raw Pre-Boil" amounts because of these additional amounts and losses. The numbers represents the amount of wort you should have prior to boiling, and at a pre-boil gravity needed to achieve the proper post-boil gravity (given the Water Needed figures).

2) The Second is the Raw Pre-Boil Targets. This is the "perfect-world" pre-boil number, where exact tolerances are met and no additional amount or losses are recorded. The numbers represents the amount of wort you should have prior to boiling, and at a pre-boil gravity needed to achieve the proper post-boil gravity. Only the targeted final volume, gravity, evaporation rate and boil time are taken into account.

3) The third is the Post Volume Targets, and are simply the target batch size and gravity of the recipe.



TIA
 

nonicman

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Raw Pre-boil Target.
Amount of water needed to give a final volume of wort for your fermenter whoops kettle.
e.g The distance between Brisbane and Sydney (in a straight line).

Water Needed Pre-Boil Target
Same as "Raw Pre-boil Target" but with the real world factored in,
the distance between Brisbane and Sydney factoring in the extra distance due to the road not being dead straight.

hope that helps, I bet you understand the passage, but for some reason refuse to believe it, like spelling, often I type a simple word and swear it's wrong, look it up and it's correct. :unsure:

I meant kettle not fermenter

:unsure:
 

MCWB

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As I understand it, 2) = if you want to end up with 19 L of 1.050 wort, how much 1.0## wort will you need to boil for the 75 minutes you've decided on?

1) = OK I know from 2) how much I need to start off with if I'm to hit 19 L of 1.050 wort, but I know I'll lose 300 mL to hops/trub, 750 mL to boiler deadspace, 250 mL to my chiller etc, so how much more wort than in 2) do I need to start off with to make up for all these losses?
 

Goat

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Thanks chaps.... I need a beer to clear my head here....

The reason I'm getting into this is (partly) beacuse of a cock-up I made last weekend... On getting what I thought was my pre-boil volume, I took a reading with the refracto which told me I was under the target pre-boil gravity. So I went up to the house and punched some numbers into Promash to see how much I should reduce the volume by (boil off) to get to my target. (At this point I was abducted by aliens) So 5 minutes later I walked back to the shed and ADDED 5 litres of water to the kettle and proceeded with the boil !

Taking a reading after the boil I couldn't work out how I got 1.037 into the fermenter in stead of 1.050. It was at that point that I had flashbacks of a bright light and skinny dudes with big eyes.....
 

AndrewQLD

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Goat, I have to ask, did you calibrate your refrac with your hydrometer, on my last brew I had some wierd readings from my refrac when compared with my hydro, and I am not sure which one is correct. The readings are about 0.005 difference. If I go by my hydro I am spot on but by the refrac I am 0.005 under!!!

Anyone know how to calibrate these this correctly.

Andrew
 

Goat

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Distilled water is all you need. Bung it on the slide and screw in the adjuster till it hits zero (I think).

I used condensed steam from my kettle (coffee/tea type kettle) though someone commented that this was a bit dodgey IIRC
 

JasonY

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Goat, the water targets on that page only serve to confuse you :) You should use the water needed calculator to figure out what you are doing when you brew. I don't even look at these numbers while brewing, only the water needed calculator.

To answer your question:

1) This is the real preboil volume you need on your system which accounts for your evapouration, kettle, hopback, chiller and other losses & cooling. You tune promash by setting up all the losses and its just a matter of making sure you have the correct preboil volume (assuming you hit your extraction)

2) Never bothered to use the raw stuff but I believe it is = BatchSize(recipe page) + EvapLosses. So this is some kind of measure of what you would need if there were no losses and water didn't expand when heated yadda yadda ... can't see the point of it myself

3) Post boil straight from your recipe design.
 

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