Does draining too fast cause low efficiency?

I've been having problems with my SS braid in my 10 gal round cooler because it was getting clogged and draining very slowly (taking around 90 min for a 10 gal batch). So I build a copper manifold and used it for the first time today and I thought it was working great. It took about a gallon to clear during vorlauf and then ran quickly and clear. I had the ball valve about 1/2 way open.

I split the batch sparge into two 3 gal sparges (instead of the six gallon sparge beersmith calculated). I thought I was having a perfect brew day and it was the fastest one yet at only 3.5 hours, but when I checked my OG, it was only 1.047 which gave me a sad 58% efficiency. With the SS braid I was getting 75-80% efficiency, so I was a little disappointed in 58%.

I was wondering if I should not have opened the ball valve as much as I was draining the MLT, maybe only 1/4 open so the wort drains slower and more sugars are washed.

Other important info: I mashed at 151 degrees (a little low of my target of 154), then round 1 of batch sparging was at 185 degrees and the second round was 175 degrees.

Grain bill:
9 lb 2-row
8 lb Munich
1 lb Chocolate malt
0.5 lb crystal 60

OG 1.047
expected OG: 1.061

Yes, slow down the sparging process. Do not mash out. Stir in 185F sparge water and wait a few minutes for the sugars to come out of the grains and then recirculate and drain. Sparge water should be 185F or you will not get the mash up to temperature for good efficiency. 2 equal sparges are best.

I didn't mash out. I drained completely after the 60 min mash and then added 3 gal of 185 sparge water, drained again and then added the last 3 gal of 175 sparge water (I didn't make the second sparge 185 degrees because I was afraid the grain bed would get hotter than 168 and start to extract tannins). I stirred for a minute or so after adding the sparge water and then immediately began to vorlauf. Would I benefit from waiting 10 min after adding the sparge water and stirring? Waiting 10 min would still be faster than waiting the 45 min for it took to sparge with my SS braid.

You can drain a batch sparge as fast as you can.
Add all the water at once, stir and leave to let the grain settle and dissolve the sugar then open the valve up full.

Are you sure your braid was stainless and not plastic? I never had a stuck sparge on the old braid.

If your crush is really coarse, you might benefit from waiting about 10 minutes after each batch infusion/stir. With my crush, waiting is just a waste of time.

Did you stir the mash good after adding sparge water both times and voraluf again? I would up the temp on the second sparge also.

When you add your sparge water to the tun, the sugar in the grains will dilute in the water until they are in equilibrium, same concentration in the wort as in the grains. Once this happens, there's no gain to be had from sparging slow or fast. The only time you'll see a gain in efficiency from batch sparging slowly is if you're not mixing well enough.

Did you take your OG read from your first runnings? It could be that the mash didn't work as well as expected and that's where you lost efficiency.

I have a 5g round cooler, and usually fly sparge. A couple months ago, I did an experiment, measuring the gravity of the mash during the 60 minute mash time. I reached 1.098 before adding 4.5 qts mash out water. (I fly sparge, and the mash out helps a lot with efficiency). I stirred really well (or so I thought) and then measured the gravity again. It should have dropped to 1.076 with the extra water, but I measured it at 1.032! I also stirred so vigorously that I disconnected the outlet from the false bottom from the spigot. I had to empty everything into the kettle, rinse and reassemble the false bottom, and refill the MLT from the kettle. At this point, the gravity had gotten up to 1.076. Moral of the story is that the deep grain bed in the cylindrical coolers makes it very difficult to stir effectively, and with a batch sparge, it is the stirring that dissolves the sugars and allows you to drain quickly.
With a 10g cooler, you may not have as deep a grain bed as I did (I was using 11 lbs grain), and my false bottom would make matters a little worse, but I would definitely try draining slower next time, and get some of the benefits of a fly sparge.

-a.

I noticed that I might have a little over 6 gal in my fermentor, so my efficiency isn't quite as bad as I thought (63%), but still 15% lower than my last session. I'm thinking that next time I'll up my batch sparge temp a little and also stir more vigorously.

This was also my first time pitching onto a yeast cake. It's going crazy! Two hours after I dumped the wort onto the yeast cake it was not only fermenting, but already blowing out the blow off tube. I know I didn't leave a lot of headspace with 6 gal in a 6.5gal carboy, but this batch is fermenting like crazy, I wouldn't be surprised if it finishes in less than 24 hours.

Leave it in the primary for 2-3 weeks anyway. the yeast will clean up.

I've only done AG once to date, but have another session planned for this coming weekend. I also had the braid plug up on me and I'm guessing it was the same reason. I'm interested in wet milling also but for now I'll just stick with dry milling and adding rice hulls I guess.

:rockin:

I use a mortar mixer chucked in my cordless drill to mix during my batch sparges. If you sink it low enough into the mash while running, you'll get great turnover without sucking air into the mix. A couple of minutes with this baby and you're all set. The one I picked up was the stainless steel version.

Soperbrew and I were talking about this yesterday.. both of us use rectangular coolers with manifolds and we both see better efficiency by about 5% or so by sparging slowly even with a double batch sparge. May be because we don't pulverize the grain. But it's worth a try. You could also try the Hybrid Sparge.

A good way to see how well you did is to measure your liquid remaining in the mash tun after the final sparge and you have the required preboil volume. If it is way over 10 points then you left some sugars behind. Just try to get more out of the grains next time.

as was said...plastic braid???

wilserbrewer said:

as was said...plastic braid???

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It's definitely a SS braid, I can tell by all the pricks on my fingers from trying to cut it when I first installed it.

drunkatuw said:

I wouldn't be surprised if it finishes in less than 24 hours.

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My 1.065 Christmas Stout finished in about 36 hours after pitching onto cake. Left it for a week for Clean Up....and still feelt like I shorted it a week (Till I tasted it...WOW!)