[EwingBrewing]

I currently fly sparge with roughly 170F water.
Specific gravity always seem to be on the low side.
Simple set up with two orange Igloo coolers, one for the mash tun and the other for the hot liquor tank.  5 gallon batches.
Asking for guidance on changing up my routine.
Any recommendations?
Thanks for imparting your wisdom!

[KellerBrauer]

My brewery is a gravity system that incorporates an induction burner and a stainless steel HLT.  Both of which are set higher (above) the mash tun.

You say the specific gravity is on the low side.  Can you be more specific?  When and how are you measuring the SG?  What is the pH and temperature of the mash and what are the target gravities you need to hit?

[lupulus]

If always low, simplest is to add more malt.

Others:

Dough balls
-Use water below 140F for mash in and stir well to minimize dough balls, once mixed rise temp to your desired number.

Temperature pockets
-Do a mix mid-way
-Measure temperature at both top and bottom

Channeling
-Do batch sparge

pH
-Check pH - Set to 5.4


"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." - Sherlock Holmes (A. Conan Doyle)

[BrewBama]

If always low, simplest is to add more malt.

Others:

Dough balls
-Use water below 140F for mash in and stir well to minimize dough balls, once mixed rise temp to your desired number.

Temperature pockets
-Do a mix mid-way
-Measure temperature at both top and bottom

Channeling
-Do batch sparge

pH
-Check pH - Set to 5.4


"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." - Sherlock Holmes (A. Conan Doyle)

I would add in addition to mashing in low temp to underlet the grist to help eliminate dough balls. It helped me.

[lupulus]

If always low, simplest is to add more malt.

Others:

Dough balls
-Use water below 140F for mash in and stir well to minimize dough balls, once mixed rise temp to your desired number.

Temperature pockets
-Do a mix mid-way
-Measure temperature at both top and bottom

Channeling
-Do batch sparge

pH
-Check pH - Set to 5.4


"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." - Sherlock Holmes (A. Conan Doyle)

I would add in addition to mashing in low temp to underlet the grist to help eliminate dough balls. It helped me.

Absolutely.
There may be other issues.
I forgot milling...


"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." - Sherlock Holmes (A. Conan Doyle)

[chinaski]

All or none of these issues might be happening OR it's a matter of tracking your efficiency and adjusting your recipes (more malt to up the OG).  So long as your resulting OGs are consistently low then there is an easy fix.  I don't recommend chasing down/changing anything until you know what your efficiencies are over multiple batches.

[denny]

Seems like a primary question is are you adjusting recipes to the efficiency of your system?

[chinaski]

Volumes matter as well.  When I fly sparged using the same set-up as the poster's, I over-sparged and relied heavily on boil-off to reach my final volume.  Beer were astringent and I often had stuck sparges.  Batch sparging to the rescue! 

[EwingBrewing]

Thanks for the attention to my dilemma.
The most recent brew is a robust porter.  Target Initial SG 1.074. My Initial SG 1.05
I have never taken a pH reading on the mash but can do in the future.
No dough balls.  I do stir the mash about half way through.
I am tempted to scrap fly sparging and go to a batch sparge for my next brew day.
Any suggestions on a good resource that covers the basics of batch sparging?

[denny]

Thanks for the attention to my dilemma.
The most recent brew is a robust porter.  Target Initial SG 1.074. My Initial SG 1.05
I have never taken a pH reading on the mash but can do in the future.
No dough balls.  I do stir the mash about half way through.
I am tempted to scrap fly sparging and go to a batch sparge for my next brew day.
Any suggestions on a good resource that covers the basics of batch sparging?

Www.dennybrew.com

[Kevin]

Do you monitor your gravity as you sparge? If so just stop sparging when you reach your expected pre-boil gravity OR boil longer until you reach the SG you are expecting. Either way you may end up with less volume than you want. In that case, Denny's first comment is very important... are you adjusting your recipes to match the efficiency of your system? Once you do this your gravity and volumes should both line up making for much happier brew days.

[KellerBrauer]

Thanks for the attention to my dilemma.
The most recent brew is a robust porter.  Target Initial SG 1.074. My Initial SG 1.05
I have never taken a pH reading on the mash but can do in the future.
No dough balls.  I do stir the mash about half way through.
I am tempted to scrap fly sparging and go to a batch sparge for my next brew day.
Any suggestions on a good resource that covers the basics of batch sparging?

Where and how are you deriving your numbers?  Not hitting your target by 10-15 points tells me something simply needs to be fine tuned.  But being off repeatedly by 70[+/-] points tells me there are many factors at play.

You say the specific gravity is on the low side.  Can you be more specific?  When and how are you measuring the SG?  What is the pH and temperature of the mash and what are the target gravities you need to hit?

Also, how are you measuring — what devices are you using?  Also, can you post the recipe?

[joshlaston]

Another thing I noticed years ago, forgot over my years away and relearned on my first batch this past weekend. I have noticed efficiency differences between pre-milled grain from online retailers (the recent experience was MoreBeer) that may have been milled a month prior for packaging or something milled a day prior at my local homebrew shop. This may not be the whole answer, but in my experience, it can be as much as .01 difference. It tends to lean closer to .003, but Saturday I missed my post-mash gravity by .006

[denny]

Another thing I noticed years ago, forgot over my years away and relearned on my first batch this past weekend. I have noticed efficiency differences between pre-milled grain from online retailers (the recent experience was MoreBeer) that may have been milled a month prior for packaging or something milled a day prior at my local homebrew shop. This may not be the whole answer, but in my experience, it can be as much as .01 difference. It tends to lean closer to .003, but Saturday I missed my post-mash gravity by .006

The difference is likely due to the milling, not the age.

[lupulus]

...and premilled grain will absorb humidity much faster if not perfectly packed.
Humid milled grain is more sticky and prone to dough balls.

"It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." - Sherlock Holmes (A. Conan Doyle)