First all grain is a disaster!

[Wrecked]

My understanding is SG = pre-boil gravity and OG = post boil gravity.

Sent from my iPhone using HB Talk

 

[SwampassJ]

This is why it's nice(convenient) to have a refractometer.

Take a sample and stick it in the freezer for 20-30 minutes then pop in the hydro. Might still be 90-100 but it's close enough for a ball park measurement.

 

[BeerMe21]

This is why it's nice(convenient) to have a refractometer.

And/or not being overly buzzed while brewing

 

[Flomaster]

I don't know the difference betwee OG and SG (and don't feel like looking it up at the moment) but I ened up hitting my target, ridiculously. In hindsight it's very likely my hydrometer readings were out of whack since I didn't even consider temp (even though I was told to do so). Anyway, I'm still not sure what I miscalculated that had me with 7+ gallons at the start of the boil, and I'd like to sort that one out.

boil time and boil off rate effect how much wort you start your boil with, also factoring in grain absorption all 3 things effect how much starting wort you need.

-=Jason=-

 

[natewv]

I guess what I'm asking is my planned pre goil amount was 5.5 gallons and I seemed to have almost all 7 that I started with. I did not squeeze the bag during mash or sparge, but it seems I ended up with almost all the water I put in. What could change in my calcs to account for that?

 

[tennesseean_87]

Did you calculate absorption in the sparge? If I understand correctly, the grains shouldn't absorb anything while sparging because they've already absorbed all they can absorb while sitting in the mash.

 

[natewv]

Ok so did 2 AG BIAB brews this weekend. My biggest lessons learned:

1) a hydrometer is temperature dependent (ha!) and
2) sparge runnings will be way less gravity than mash runnings.

I am still at a loss about the gallon plus of extra wort each brew had. Almost 7 gallons each time.

Everyone's advice has been great, but I understand that I have miscalculated somewhere, that's evident. What I need some thoughts on is how I miscalculated, and how to fix it.

Now that I have a bunch of data and 10 gallons of beer bubbling away, what things should I try to manipulate in my software? For example, how do i calculate my brewhouse/equipment efficiency?

 

[natewv]

delete

 

[natewv]

delete

 

[natewv]

Did you calculate absorption in the sparge? If I understand correctly, the grains shouldn't absorb anything while sparging because they've already absorbed all they can absorb while sitting in the mash.

umm, I'm not sure. I'm using beertarget 1.2.3 , I am not sure what it calculates for me.

And not sure about your quamtity of wort, how much you end up with? You probably just over estimated mash ratio or sparge water. If you think you have too much you can always just boil off a little more, the extra boil time won't hurt.

How do I more accurately estimate this?

Also, how do I estimate brewhouse efficiency? I just assumed 70% since I haven't done AG BIAB before.

just grab a sample with a pyrex measuring glass and cool it down enough to measure the gravity if you want to know where you are.

I think your OG is higher than you thought, because 1.066 first runnings + 1.016 sparge does not add up to 1.036 OG unless your sparge volume was 1.5 times your first runnings. with the numbers you gave for first runnings and sparge volumes and gravities, you should have ended up around 1.046 OG.

what equation do you use to combine first and second runnings?

 

[BrewKnurd]

what equation do you use to combine first and second runnings?

Just a weghted average the gravities. e.g. if you have 5 gallons at 1.060 and 2 gallons at 1.020:

(1.060*5 + 1.020*2)/(5 + 2) = 1.049