Whats with my gravity

[Skillz]

I cant figure out why my gravity was so low with my pre boil being about right and my volume being pretty close.
I use a refac and hydrometer for all readings and even took multiple samples of both to double check.
All was mixed very well.
My only thought is it must be that my boil off is less than I'm thinking but the numbers add up
???
Any thoughts

 

[wide eyed and legless]

I cant figure out why my gravity was so low with my pre boil being about right and my volume being pretty close.
I use a refac and hydrometer for all readings and even took multiple samples of both to double check.
All was mixed very well.
My only thought is it must be that my boil off is less than I'm thinking but the numbers add up
???
Any thoughts

Checking your pre boil gravity, what did you do and how did you take it?

 

[Skillz]

Checking your pre boil gravity, what did you do and how did you take it?

Stired really well and i was recirculating the whole 90 min Mash.
Took 2x refac readings and a hydrometer reading that all showed the same

 

[wide eyed and legless]

Stired really well and i was recirculating the whole 90 min Mash.
Took 2x refac readings and a hydrometer reading that all showed the same

So what was your post boil gravity? Also what was the volume post boil?

 

[Skillz]

So what was your post boil gravity? Also what was the volume post boil?

1.083 and 12.2l

 

[Sidney Harbour-Bridge]

The numbers nearly add up, if the volumes are correct using the pre-boil gravity, post boil gravity should be 1.086. How accurately do you measure the volume and what temperatures were the hydrometer readings taken at?

 

[Skillz]

The numbers nearly add up, if the volumes are correct using the pre-boil gravity, post boil gravity should be 1.086. How accurately do you measure the volume and what temperatures were the hydrometer readings taken at?

I just did the maths and that is correct, so why does brewfather predict a final gravity of 1.097, seems like somthing in the software is wrong

 

[wide eyed and legless]

I just did the maths and that is correct, so why does brewfather predict a final gravity of 1.097, seems like somthing in the software is wrong

No, it can only predict the preboil gravity it can't predict how your mash went. For me I would say an error occurred in the pre boil reading or as you first stated the boil off.

 

[Skillz]

When you put into the calculator a 16.9l pre boil with a gravity of 1.062 and a boil off of 4.4l and a target gravity of 1.083 it says that it would be a 58 minute boil off which is pretty much what I got so why does my recipe think that it would get to 1.097?

 

[Half-baked]

Is it a recipe issue? E.g. have you entered into Brewfather a sugar addition during the boil?

 

[Skillz]

Is it a recipe issue? E.g. have you entered into Brewfather a sugar addition during the boil?

I added the sugar to the mash as to get an accurate pre boil read, has got me stumped

 

[Skillz]

I added the sugar to the mash as to get an accurate pre boil read, has got me stumped

Is it a recipe issue? E.g. have you entered into Brewfather a sugar addition during the boil?

Your right this is the answer, I just checked and the recipe doesn't state when the sugar will be added hence I just assumed it was part of all the fermentables at every measurement.
Looking at the actual brew schedule it is to be added in the boil hence it wouldn't be part of the pre-boil reading.
Long story short it looks like I didn't hit my mash efficiency.

 

[wide eyed and legless]

Your right this is the answer, I just checked and the recipe doesn't state when the sugar will be added hence I just assumed it was part of all the fermentables at every measurement.
Looking at the actual brew schedule it is to be added in the boil hence it wouldn't be part of the pre-boil reading.
Long story short it looks like I didn't hit my mash efficiency.

Still doesn't explain the difference in the two readings. The sugar doesn't get boiled off, only the liquor. So you take a reading pre boil if the reading is 100% accurate then the reading taken post boil should read what calculator predicts for the volume left. The sugars between pre boil and post boil are still in the mix, only the volume has changed.
Even though you checked and believed you had the pre boil reading right I doubt it was.

 

[Skillz]

Still doesn't explain the difference in the two readings. The sugar doesn't get boiled off, only the liquor. So you take a reading pre boil if the reading is 100% accurate then the reading taken post boil should read what calculator predicts for the volume left. The sugars between pre boil and post boil are still in the mix, only the volume has changed.
Even though you checked and believed you had the pre boil reading right I doubt it was.

To my understanding the pre boil reading does not include the sugar addition so the expected preboil gravity was ment to be 1.061 and I got 1.062 but that had the sugar in it, if you remove that sugar using a calculator it means I got a pre boil of 1.052ish which makes sense to me