Please help me find my error(s)

[queenster]

Hey guys,
In my first AG batch today my OG was a bit lower than I expected and I am looking for help in finding why. I am pretty sure it is just that my efficiency was low, but if any of you can help I would appreciate it.

How the day went:
Recipe: 13 lb 6 row, 1 lb 40 crystal, 0.5 lb carapils plus the bitter buddies and some irish moss
I was shooting for a low end imperial IPA
I mashed with 3.5 gal in a 5 gallon cooler and temps ranged from 151-154 throughout the 60 min.
I sparged with another 3.5-4 gallons and got to a 5.5 gallon boil.
Boiled 75 min with hop additions.
Added 1/4 cup table sugar at flame out (I know it is not great, but I didnt have corn sugar and I needed a little boost)
After topping off the wort I end up with a 6 gallon batch (I didnt realize how much my pot held and over filled a little)
I pitched Safale 05 and am waiting for some lock popping to start.
My OG was 1.043. I tested my hydrometer and it was .002 off so I could say 1.045, but still much lower than I needed for this one.
Can some of you brew vets point out all my mistakes here so I can improve my efficiency? Thanks in advance.

Queenster
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Posts: 1
Joined: Sat Aug 08, 2015 9:07 pm

 

[Brewskey]

3.5 Gals of water doesn't really seem like enough water to mash 14.5lbs of grain. Shoot for 1.25-1.5 qts of water per lb of grain so, in this case, 4.5-5.4 Gals of water. I bet you'll have much better results with more mash water

 

[Yooper]

Hey guys,
In my first AG batch today my OG was a bit lower than I expected and I am looking for help in finding why. I am pretty sure it is just that my efficiency was low, but if any of you can help I would appreciate it.

How the day went:
Recipe: 13 lb 6 row, 1 lb 40 crystal, 0.5 lb carapils plus the bitter buddies and some irish moss
I was shooting for a low end imperial IPA
I mashed with 3.5 gal in a 5 gallon cooler and temps ranged from 151-154 throughout the 60 min.
I sparged with another 3.5-4 gallons and got to a 5.5 gallon boil.
Boiled 75 min with hop additions.
Added 1/4 cup table sugar at flame out (I know it is not great, but I didnt have corn sugar and I needed a little boost)
After topping off the wort I end up with a 6 gallon batch (I didnt realize how much my pot held and over filled a little)
I pitched Safale 05 and am waiting for some lock popping to start.
My OG was 1.043. I tested my hydrometer and it was .002 off so I could say 1.045, but still much lower than I needed for this one.
Can some of you brew vets point out all my mistakes here so I can improve my efficiency? Thanks in advance.

Queenster
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Posts: 1
Joined: Sat Aug 08, 2015 9:07 pm

Topping off (I assume with water) to six gallons means adding a gallon of water at least, if you started with 5.5 gallons of wort. That will really mean a lowered OG, as you're diluting the wort with water with 0 fermentable sugars.

 

[Subdivisions]

I calculated that you're a gallon short on the mash water, minimum.

Looking at yooper's post I noticed how much water you probably had to use to get to six galllons (which I will say you don't need to be that high, 5.5 is fine), you must've boiled off at least a gallon in a 75 minute boil so you had to have added 1.5 gallons to get to 6. That's where your big mistake is. Get more wort before the boil and boil down to your final amount

 

[Calder]

45x6=270; this is the total gravity points you got.

270/14.5=18.75; this is the points per lb you got.

18.75/36=52%; this is your mash efficiency. That is pretty poor. You need to shoot for at least 70%. I get 80 to 85%.

You need more water in your mash, but low water/grain ratio should not be a big factor.

Grain crush makes a big difference. Try a finer crush, or double crush and see what happens.

Let the sparge water sit a little longer and stir it. What temp was the sparge water; it should be close to 160 F after adding to the grain, so probably closer to 170 F when adding it.

For an IPA I would mash 1448/150. It helps it ferment drier.

 

[doug293cz]

Ran your grain bill, volume and gravities thru a sparge calculator I am working on. I get your mash efficiency at about 54% (my value is higher than @Calder since I am figuring in grain moisture content.) I have your lauter efficiency at about 76%. Since:

Mash Efficiency = Conversion Efficiency * Lauter Efficiency​

That leaves your conversion efficiency at about 71%, which is extremely low.

Conversion efficiencies in excess of 95% are readily obtainable. The reasons for your low conversion efficiency are probably related to:

• Low strike water to grain ratio. Thick mashes convert slower than thinner mashes, so a longer mash and/or more strike water should help.
• Mash time too short for crush coarseness. Coarser crushes take longer to convert than finer crushes, so a finer crush and/or longer mash should help.

Your lauter efficiency is also on the low side. The low strike and sparge volumes dropped your lauter efficiency by about 7 percentage points. Had you used 5.25 gal of strike water, and 3.75 gal of sparge water (9 gal total), your lauter efficiency could have been about 83%. This would have netted you about 7.25 gal pre-boil, which should have netted about 6 gal post-boil without requiring top up water. The thinner mash due to more strike water would have helped your conversion efficiency as well.

Brew on

 

[queenster]

Thanks guys for the input. I think my hiccup is my setup then. I am using a 5 gal cooler for mash/lauter, and my brewpot is about 6 gal max, so I am just under the threshold you guys would recommend for both mash and boil capacity.

If I ran a lower grain bill and did a 10lb mash I think I could hit the right numbers for my water/grain ratio.

I just hope this beer turns out ok. I am looking at around 75 IBU, but with this low OG it may be a just bitter with no body.

Either way I will drink it all, even if it is just to force me to stick to ratios that my setup can handle.

Thanks again.

 

[doug293cz]

You're either gonna need to get a bigger MLT and BK, drop your batch size so things fit better, or settle for poor efficiency.

Brew on