What is the difference between...

[Texas Ale Works]

Mash complete and pre-boil gravity readings in a BIAB context

 

[Minbari]

I am sure you can make any determination you want. but this is how I do it.

mash SG is what the wort is after you are done mashing, but havent added water for the boil yet.
pre-boil is after top-up water, so you can account for boil off.
post-boil is after the boil, but before any fermentor top-up water, if needed.
OG is after fermentor top-up, if any is needed. sometimes they are the same.
FG is after fermentation.

 

[oliver]

mash complete = no sparge, no bag squeeze and straight from the mash vessel
pre boil = sparged, squeezed, mashed out, straight from the kettle

more readings let you make more adjustments at different spots in the brew day.

 

[Texas Ale Works]

Yeah, so in my typical BIAB day, I mash -> Lift Grains and let drain for a bit -> set PID to 185 ish to start heating the wort for boil ->Squeeze the grain bag (mainly to make it easier for clean up, but also to get the last bit of wort out -> Take Gravity reading - ramp to boil.

in this workflow becasue I do not check the gravity before I squeeze the bag Mash Complete and Pre-boil would be the same reading, correct?

Thanks

Tim

 

[Sunfire96]

Yeah, so in my typical BIAB day, I mash -> Lift Grains and let drain for a bit -> set PID to 185 ish to start heating the wort for boil ->Squeeze the grain bag (mainly to make it easier for clean up, but also to get the last bit of wort out -> Take Gravity reading - ramp to boil.

in this workflow becasue I do not check the gravity before I squeeze the bag Mash Complete and Pre-boil would be the same reading, correct?

Thanks

Tim

You are technically taking the pre boil gravity. Your mash complete reading would be before you lift the bag

 

[Pricelessbrewing]

mash complete = no sparge, no bag squeeze and straight from the mash vessel
pre boil = sparged, squeezed, mashed out, straight from the kettle

more readings let you make more adjustments at different spots in the brew day.

This.

The main difference allowing for BIAB + sparge / grain bag drainage. The SG should in theory by very similar, but preboil is likely more accurate is it allows for thorough mixing whereas mash complete often has significant stratification.

 

[Minbari]

Also if you add water for boil off, then your SG will go down some, that is still pre-boil.

I think the key is doing it the same each time, no matter how you do it. Random data is hard to make sense of

 

[Pricelessbrewing]

Also if you add water for boil off, then your SG will go down some, that is still pre-boil.

I think the key is doing it the same each time, no matter how you do it. Random data is hard to make sense of

Yeah, whether you're sparging or adding topoff water, if there's any water being added between the mash complete and preboil that will be a significant difference.

 

[Texas Ale Works]

Cool, thanks everyone....I just enter the same number for both...

 

[Megary]

Cool, thanks everyone....I just enter the same number for both...

That’s what I do.