Too much wort left in tun?

[JohnK93]

Hello all,
I just brewed my second all-grain batch (10+ batches total). I nailed my OG on my first all-grain batch, but on this one I was a bit low. Targeted 1.056 and measure 1.044. I know there are a lot of reasons it could be off, including the milling (it was milled by the same shop as my first), mash ph, style (this was a pale ale, first AG was an american wheat), and boil off (seems the same as the last ag batch) etc. All my temps were right on.

My question regards the amount of sparge water. I collected about 1.25 gallons from my first runnings (didn't measure gravity) and batch sparged with another 3.5 gallons. After filling my kettle to 4 gallons, my max boil volume for now, another.8 gallons of wort remained in the tun. I measured its gravity to be about 1.02. If I had sparged with 3 gallons, would my OG have increased? Said another way, did I miss out on some sugars by leaving .8 gallons in the tun?

Thanks,
John

 

[GilSwillBasementBrews]

Long story short yes. You want to get as much liquid out of the mash tun as possible to give you the most sugars possible in the Boil Kettle. You can always sparge with more water and boil it down to the volume desired or till you reach the OG your looking for.

 

[JohnK93]

Thanks for the quick response. How many points do you think this could have contributed? I'm limited to a 4 gallon boil right now and I'm trying to walk the line of doing all grain but still ending up with a decent yield. Should have dumped that .8 gallons into the kettle as it boiled off and boiled for longer than 60 minutes until I reached my OG?

I'm OK with a lower ABV, but of course I'd like to be able to predict it better.

 

[chickypad]

0.8 gallons of 1.020 wort would have 16 gravity pts. Spread over a 5 gallon batch that's only a little over 3 pts. If you were 12 pts off sounds like need to do some more trouble shooting.

Edit: just noted you're only boiling 4 gallons. What is your batch volume? Also out of curiosity what efficiency do you have the recipe set at?

 

[mikescooling]

You can save that wort and use it for starters. But you have to boil or pressure can it.

 

[JohnK93]

With a starting boil volume of 4 gallons, I expected to put about 3.25 into the fermenter, so this was my batch volume. I ended up putting a little over 3 into the fermenter. I had the recipe set at 70%, which worked out perfect for my first AG batch. Could have been the crush, but the shop crushed it both times so I figured it'd be the same. Maybe something to do with how fast I ran off the wort, but I thought I was going pretty slow considering I was batch sparging. Maybe not enough stirring? Maybe some sort of channeling in my tun? (I'm using a false bottom)

Well, I guess the only thing to do is brew more beer and try to figure this out.

It was nearing 90 degrees in my kitchen after the boil...canning was the last thing I wanted to do!

 

[mikescooling]

You can stick it in the fridge for a few days. I don't pressure cook it the day of the boil ether. The nice thing about canning it is when you want to do your starter you don't have to boil anything, it's ready to go out of the jar/jars.