Efficiency Problem

4th AG batch learned alot from the first 3. All of them had horrible efficiencies. I am able to explain them all and again I learned from the mistakes. My 4th went very well, 1 hour mash at 155. 173 deg sparge water. I fly sparged for 75 minutes. I got 6.5 gal in the BK. I used a refractometer and the gravity reading at the end was 1.010. So I am assuming I got most of the sugar out. Beersmith says OG should be 1.064. I did a 105 minute boil and was left with 5 gallons. The problem is my OG is 1.049. I read it with the hydrometer and with the refractometer and they both said the same thing. The only thing that was different is I used some phosphuric acid to lower the pH in the HLT before I heated and sparged. If my sparge water has too low a pH can it effect efficiency???

I never add phosphuric acid to my sparge water....but unless you're getting it way below 5.2, I don't think it's going to change your effeciency much. The number one factor to effeciency, barring inaccurate measurements, is always crush. Make sure your grain is crushed so that there's no husks that are intact.

I don't think that the pH of the sparge water will have any effect on efficiency, but a low pH can help prevent excess tannin extraction.
I increased by efficiency by 10% when I started doing a mash out. If you are not doing a mash out, and are fly sparging with 173F sparge water, then I doubt that the temperature of the grain bed is getting out of the 150's
If you are using a braid, or a manifold without cross bars, you are likely to get channeling with a fly sparge. This can result in the final runnings having a low gravity, but still leave a large amount of sugars trapped in the grain.

-a.

I left that out, I did do a 168 deg mash out prior to sparging. I do use a sparge arm (non rotating) I also use a T-Bazooka for the seperator. And as far as the crush it has been done at my LHBS not that that makes it good. I kept the sparge water 2-3 inches above the bed. If there is channeling what can I do

If it is a channeling problem, you could try batch sparging which wouldn't cost anything, or you could replace the Bazooka with a false bottom or a home made manifold. I'd use a false bottom if the MLT is round, or a manifold if it's rectangular.
Palmer has a good explanation of manifolds at How to Brew - By John Palmer - Building the Manifold
Before you make any changes however, you could check out https://www.homebrewtalk.com/f36/channeling-check-fly-sparging-53713/ to see if it is indeed a channeling problem

Hope this helps.

-a.

ajf said:

If it is a channeling problem, you could try batch sparging which wouldn't cost anything, or you could replace the Bazooka with a false bottom or a home made manifold. I'd use a false bottom if the MLT is round, or a manifold if it's rectangular.
Palmer has a good explanation of manifolds at How to Brew - By John Palmer - Building the Manifold
Before you make any changes however, you could check out https://www.homebrewtalk.com/f36/channeling-check-fly-sparging-53713/ to see if it is indeed a channeling problem

Hope this helps.

-a.

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This is great! Thanks for the info. :rockin: