OG way off. What went wrong?

Brewed the AG brick warmer yesterday. I usually batch sparge and get the OG correct or a little higher. Yesterday I decided to fly sparge. Everything went well but when I checked the cooled wort the OG was 1.048 when it should have been 1.062

How did this happen? Did I fly sparge incorrectly?

Paul

How did you crush the grains? Crush variability is the biggest reason why efficiency can change.

Second biggest reason? Measurement errors. Is your hydrometer calibrated and volume on target? How about your thermometer that you used to confirm mash temperature?

After that, you can get into minor factors like mash pH, mash thickness and volume of each sparge, but those shouldn’t be enough to cause the drop you saw.

I double crushed the grain. The crush looked good. Thermometer, hydrometer are calibrated ok. Volume was ok. The only thing I did different was the fly sparge versus the batch sparge.

I’m thinking maybe I sparged too quickly?

[quote=“Brews-R-us”]I double crushed the grain. The crush looked good. Thermometer, hydrometer are calibrated ok. Volume was ok. The only thing I did different was the fly sparge versus the batch sparge.

I’m thinking maybe I sparged too quickly?[/quote]
Chances are you did. I fly spare and it should take 45-60 mins. Another thing to remember is to maintain 2" of water on top to help push out the wort.

[quote=“Brews-R-us”]I double crushed the grain. The crush looked good. Thermometer, hydrometer are calibrated ok. Volume was ok. The only thing I did different was the fly sparge versus the batch sparge.

I’m thinking maybe I sparged too quickly?[/quote]

Maybe. I think it’s more likely that your lautering system is well designed for fly sparging.

Yep, I sparged in 15 to 20 minutes. And water level was not above grain, maybe level with it at best.

That is too fast. What’s your lautering system like? A manifold or false bottom?

I have a false bottom, 10 gallon round cooler. For the 5 gallon batch I was doing the grain was maybe about 1/3 the volume in the cooler.

Yeah sounds like you did a pseudo batch/fly sparge. I’ve found that it doesn’t work that way. Either batch or fly will work, but you have to pick one and stay committed to it.

I agree. Rushing a fly sparge can cause the sparge water to channel and not get to a lot of the grain. Restricting the flow out of the MT and keeping the water level above the grain will fix it. Once I start to reach my desired amount of wort I will stop the water and let it drain.