Need some thoughts...Low O.G.

[Pugs13]

Alright guys we have an issue that we have noticed while all grain brewing with our equipment. We use a standard a 10gallon round cooler for mash tun, 5gallon round cooler for hot liquor, and collect into boil kettle. Essentially an easy 3 tier system. We have brewed 2 batches of an IPA and have had the same results both times, low O.G. resutling in boiling up extra DME to jack the gravity up. After figuring out the potential problem with the 1st batch being the mistake of top of water diluting, we made upgrades and changes to our process and equipment to ensure we end up with 6gallons of wort and boil down to 5gallons.
This second time we brewed we treated our water for proper pH and did the dough-in at 167-168F to get to 154F and maintained that for 60min. We did the iodine test at 60min. to see if conversion was complete. Iodine turned light brown to clearish when dripped into wort so I was convinced conversion was good. We then did our vorlauf process to ensure clarity and set up our grain bed for natural filtration by collecting runoff into a 4c. measuring pitcher and proceeded to do this process 4 times until wort ran clear. After that we started our sparge process with 168F water maintaining 1"-2" water above grain bed. This process took about 30-35min. and were able to collect 6 gallons of sugary wort. We then did our boil for 60min. added our hops and Irish moss, cooled with wort chiller to 65F-67F and pitched our yeast starter.

Here is our recipe for grains.
12lbs. - Golden Promise
12oz. - Caramel 60L
4oz. - Acidulated Malt

O.G. - 1.063
F.G. - 1.016
SRM - 9
ABV - 6.3%

On both batches we hit a gravity of about 1.045 +/- .002
Is there something in our process we are doing wrong? I am assuming we are running at about 70%-75% efficiency out of our equipment, just the fact that it happened twice and ended up about the same I am assuming its our process or equipment limitations. Is the answer that maybe we just need to up our base malt to ensure more sugars? Please let me know because I am going crazy having to boil up DME at the last minute!! Thanks guys!

 

[cvstrat]

Perhaps try a finer grain crush.

I'm not able to put the recipe into a calculator right now to check, but are you sure that's the proper OG?

 

[Pugs13]

Perhaps try a finer grain crush.

I'm not able to put the recipe into a calculator right now to check, but are you sure that's the proper OG?

I was also thinking about the grain crush. I am not experienced enough to know if the Home Brewing Store has it setup right or how to set it up. Upon appearance the grain seems cracked nicely with the starches revealed and husks or shells intact but like I said I am not that intuned to knowing exactly if it is completely right or not. The calculator I use is the Hopsville beer calc. and after putting this recipe together those are the numbers it has given me. I guess I can try another calc. and see what it says. Do you think that we may just need to up our grain bill? If so, how much more Golden Promise would it take to get to where we need to be?

 

[Pugs13]

I was also wondering because sometimes its confusing to me but...if we are collecting a total of 6 gallons of wort to boil...should my recipe be for a 6gallon batch? Even though we are boiling down to 5 gallons? Maybe this is where we are going wrong...If I redo the recipe for a 6gallon then that ups my grain bill 2.5lbs. to get to where the O.G. should be...hmm...but not sure of this either because when we do our lower gravity stout which is only 1.045 we can hit that target just fine! It's just this IPA or higher gravity beers we are having issues with...

 

[wilserbrewer]

I suspect the crush? Try running through the mill twice at your LHBS. You used the word cracked....with hulls intact, that sounds light to me. Or try a batch sparge, perhaps you are channeling during the fly sparge??? What type of lauter device is in your MLT?

 

[Pugs13]

We can try crushing a second time next time we brew. Otherwise I have changed the efficiency on our brew calculator to 65% instead of 75%. This allowed me to up the grain bill to bring up our O.G. We use just a 5g cooler that drains down to a homemade sparge system made of copper tubing. It's basically a spiral/coil with small holes in it that covers the grain bed. Works nicely. Just think our recipe may be setup for 75% efficiency when we are actually only running at 60%-65%.

 

[wilserbrewer]

Just a heads up....if its the crush...a better crush could jump you into the eighties.

 

[Cellarbrau]

I'm sure it looks great but I'd say it doesn't 'work nicely'. The only advantage in fly sparging is efficiency and you aren't getting it.

So batch sparge.

 

[damnitbeavis]

You will need more information about your process here... What was the gravity of the final runnings? What was your pre boil volume and gravity? post boil volume? I am suspicious you may be stopping your sparge too early. Do you continue to monitor your mash tun temps during your mash? How do you add heat?

 

[mvcorliss]

I always calculate my batch size as what goes into the fermenter. I roughly figure 7 gallons into kettle, 6 gallons left after boil and I lose about 1/2 gal to trub. So I calculate for a 5.5 gal batch with about 5 gal into bottles. The exact figures of course change with the recipe.

I would look at your crush but I agree with Wilserbrewer that you could also be looking at your lautering. Fly sparging can be tricky if you go too slowly or too quickly. You can also lose efficiency if you are channeling the grain bed or if your manifold is not set up correctly. You might give batch sparging a try. The theoretical loss of efficiency vs fly sparging assumes both are done perfectly. Batch sparging is easy to get do well, fly sparging can be tricky.

 

[Northcalais40]

I'm with Beavis and Corliss on this one. Try a batch sparge, it will help diagnose the problem. If you get a good batch sparge result, the mlt isn't working well for a fly sparge.

Also sparge speed is critical (for fly), 1 hour+ for 5 gal.

Calculate efficiency based on what volume ends up in the fermenter. Measure the gravity at the start and finish of sparging.

 

[Pugs13]

You might give batch sparging a try. The theoretical loss of efficiency vs fly sparging assumes both are done perfectly. Batch sparging is easy to get do well, fly sparging can be tricky.

Can you break down a batch sparge process for us? I guess I don't understand how fly sparging can go so long...maybe that is the issue...we can only make it last like 30min. and keep 1-2" of sparge water above grain bed. We must be doing something wrong...we can try batch sparging but like I said can you break it down for us please. Thanks for the help everyone...

 

[LouBrew13]

Dial back your flow valve from your mash tun. My fly sparge takes at least an hour for the same volume. Slow and steady wins the race.

 

[ajf]

What do you have in the bottom of your MLT to filter out the grains? False bottom, manifold, or braid?
If you have a braid, I would suggest either switching to a batch sparge, or upgrading to a false bottom or manifold. (The braid doesn't work well for fly sparging as it encourages channeling.
If you have a manifold or false bottom, you have effectively the same equipment as I do. The only things I do or may do different are:

1. I mash at 1 qt/lb for UK malts. This leaves more water for sparging
2. I do a mash out at the end of the mash and stir well. When I started doing this, my efficiency improved by 10%
3. I usually sparge a bit slower than you. A 30 minute sparge is fine for a 1.040 OG, but I take longer (45 - 60 minutes) for something around 1.060
4. I use sparge water at 180F. By the time it has meandered through the tubing to the sparge arm, it is about the right temperature.

Hope this helps,

-a.

 

[Northcalais40]

Dennybrew.com is a good source for batch sparge info.

 

[Pugs13]

What do you have in the bottom of your MLT to filter out the grains? False bottom, manifold, or braid?
If you have a braid, I would suggest either switching to a batch sparge, or upgrading to a false bottom or manifold. (The braid doesn't work well for fly sparging as it encourages channeling.
If you have a manifold or false bottom, you have effectively the same equipment as I do. The only things I do or may do different are:

[*]I mash at 1 qt/lb for UK malts. This leaves more water for sparging
[*]I do a mash out at the end of the mash and stir well. When I started doing this, my efficiency improved by 10%
[*]I usually sparge a bit slower than you. A 30 minute sparge is fine for a 1.040 OG, but I take longer (45 - 60 minutes) for something around 1.060
[*]I use sparge water at 180F. By the time it has meandered through the tubing to the sparge arm, it is about the right temperature.


Hope this helps,

-a.

We use just a braided hose in our MLT right now but thinking about looking into a false bottom. This information will help a ton. We have actually been doing 1.5qt./lbs. in our mash process so maybe we will have to dial that down a bit and leave more water for sparging.
It's just been weird because for the stout that we do we hit all our targets just fine...but like you stated it may be fine for lower gravity beers, ours being 1.045. We will have to make some changes and go from there. Thanks again!