# Water Volume - Pre Boil

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#### Mic Carp

##### Loud Mic
Apologies if this has been asked or if I asked in the wrong place (which would explain why I can't find the question already asked).

I have only a couple BIAB sessions under my belt and was doing only partial boils for years as an extract brewer. Therefore these calculations are new to me.

Finally, the question: How do I accurately measure the water volume during the course of brewing?

I made a dip stick marked with ¼ gallon increments. I am able to accurately measure out the strike water, but to calculate absorption and boil off volumes I need to take those readings.

In my first brew my values were understated into the fermenter so I had to top off to fix volume and OG. Something I was used to in partial boils. So, the next time I made and used my dip stick. I took volume reading with the water temps elevated (post mash at around 150) and during boil. Not until I racked into the fermenter did I realize that the elevated temps changed the volume (increased). My reading made me boil for an additional 20 minutes, thinking I over shot my strike volume/preboil volume, but then I ended up short again.

Is there a formula that will tell me that if temp = T then volume is T(x.x)? as you can see from my formula question, I am a simple man, but any help would be appreciated.

#### RPh_Guy

##### Bringing Sour Back
Simple:
Mash temp increases volume by 2% above room temp.
Boiling temp increases volume by 4% above room temp.

Examples:
Measured 6 gallons wort collected is actually about 5.9 gallons (6 ÷ 1.02 = 5.88)

5.2 gallons measured at the end of the boil is actually 5 gallons (5.2 ÷ 1.04 = 5)

Cheers

OP
OP

#### Mic Carp

##### Loud Mic
Simple:
Mash temp increases volume by 2% above room temp.
Boiling temp increases volume by 4% above room temp.

Examples:
Measured 6 gallons wort collected is actually about 5.9 gallons (6 ÷ 1.02 = 5.88)

5.2 gallons measured at the end of the boil is actually 5 gallons (5.2 ÷ 1.04 = 5)

Cheers

Thank you! that's exactly what I need!

Cool,
I'll check it out!
Thanks fellas!

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