First all grain batch - odd issue

[RayZab]

So I brewed my first all-grain batch the other night and attempted to do a fly sparge. I basically fly sparged to a preboil volume of 7.9 gallons in about 25 minutes (which I understand I should slow down next time). It appears that I lost a good bit of my efficiency from my sparging, as I noticed after cleaning out my MLT that there was a lot of sweet wort still left under my false bottom. I thought this to be odd as my final runnings late during sparging were almost clear. Also my valve is almost at the bottom of my kettle, so not sure why the sweet, dark wort wouldn't have drained. Anyone have any ideas why this could have happened? It's possible I was causing channeling by sparging quickly, however I doubt that would have left dark wort in the bottom. Or is it possible these are sugars that continued draining after I finished sparging (I cleaned the MLT out about 30 mins after finished sparging).

 

[Bellybuster]

After drippings......save it for starter wort

 

[day_trippr]

^Agreed^. The higher than desired residual gravity was likely due to the fast fly sparge.
Double that sparge time next batch...

Cheers!

 

[IslandLizard]

[...] Or is it possible these are sugars that continued draining after I finished sparging (I cleaned the MLT out about 30 mins after finished sparging).

This!

 

[RM-MN]

^Agreed^. The higher than desired residual gravity was likely due to the fast fly sparge.
Double that sparge time next batch...

Cheers!

Either increase the sparge time or go to batch sparging. You'll lose a little efficiency by batch sparging over a good fly sparge but you'll gain about an hour of time too because batch sparging can be really quick.

 

[doug293cz]

So I brewed my first all-grain batch the other night and attempted to do a fly sparge. I basically fly sparged to a preboil volume of 7.9 gallons in about 25 minutes (which I understand I should slow down next time). It appears that I lost a good bit of my efficiency from my sparging, as I noticed after cleaning out my MLT that there was a lot of sweet wort still left under my false bottom. I thought this to be odd as my final runnings late during sparging were almost clear. Also my valve is almost at the bottom of my kettle, so not sure why the sweet, dark wort wouldn't have drained. Anyone have any ideas why this could have happened? It's possible I was causing channeling by sparging quickly, however I doubt that would have left dark wort in the bottom. Or is it possible these are sugars that continued draining after I finished sparging (I cleaned the MLT out about 30 mins after finished sparging).

Channeling will cause regions of the grain bed not to get sparged well. Then, after long drain time, the some of wort in those un/under sparged regions would drain to the bottom of the MLT.

It's easier to conduct a proper batch sparge than a proper fly sparge. With batch sparging you don't have to worry about channeling. All you have to do is stir well prior to initial and sparge run offs. A proper batch sparge will provide higher efficiency than a poorly conducted fly sparge, while a well conducted (slow, no channeling) fly sparge will beat a batch sparge for efficiency. The batch sparge takes less time than a proper fly sparge. Do whichever method you prefer, as long as it gives you acceptable results. If your results are unacceptable, then you need to change something.

Brew on

 

[PeteNMA]

Although realistically a competent batch or fly sparge on a homebrew scale will be within 5% efficiency of one another.

 

[Qhrumphf]

I've found double batch sparging (either approximately equivalent first mash runnings and 1st batch sparge runnings plus a 3rd smaller sparge w/ less runnings, or 3 approximately equivalent runnings, I've done both to similar results) gets me the same efficiency as fly sparging, in only slightly more time than regular batch sparging. I'm sure @doug293cz may have something scientific as to why that's wrong, but that's my direct observation and I'm anal about my measurements and know my system well so I'm very confident in saying so, so for all I know it may be something specific to my system.

 

[doug293cz]

I've found double batch sparging (either approximately equivalent first mash runnings and 1st batch sparge runnings plus a 3rd smaller sparge w/ less runnings, or 3 approximately equivalent runnings, I've done both to similar results) gets me the same efficiency as fly sparging, in only slightly more time than regular batch sparging. I'm sure @doug293cz may have something scientific as to why that's wrong, but that's my direct observation and I'm anal about my measurements and know my system well so I'm very confident in saying so, so for all I know it may be something specific to my system.

With batch sparging, each additional sparge cycle gives you an incremental increase in efficiency with the total pre-boil volume kept constant. But, with each additional cycle you get less improvement than before. One sparge is significantly better than no sparge, two sparges is better than one sparge, but the improvement going from 1 to 2 is less than the improvement going from 0 to 1. And with more sparge steps you getting progressively diminishing improvements for each additional step. After two sparges, you are most likely in the range where uncertainty in grain potential, grain moisture content, volume measurements, and gravity measurements make it impossible to actually measure the theoretical improvement due to additional sparging steps.

One way to look at fly sparging is that it is nothing more than an infinite number of infinitely small batch sparge steps, done one right after the other. And, as mentioned above, the ability to measure the difference between two and three batch sparge steps doesn't exist, so we also can't measure the difference between two batch sparges and a fly sparge. If we can't measure the difference with any confidence, then the difference doesn't matter from a practical standpoint. So, while there may be a theoretical advantage of fly sparging over 2x batch sparging, in practice you can't tell the difference.

tl:dr - a homebrewer is unlikely to be able to detect any efficiency difference between a 2X batch sparge and a fly sparge.

Brew on

 

[Qhrumphf]

One way to look at fly sparging is that it is nothing more than an infinite number of infinitely small batch sparge steps, done one right after the other.

That is exactly how I've looked at it. Or rather, the corollary, the more sparge steps you divide your sparge into, the closer you approximate fly sparging.

Cheers

 

[RayZab]

Thanks everyone. I'm going to try batch sparging next time with the same grain bill and see what happens.