[benamcg]

My first three attempts at Batch Sparging have resulted in poor extract efficiency: 64, 67, and 56% in 12 gal, 6 gal, and 12 gal batches, respectively. The first and third attempts were with a different mash tun (72 qt Coleman Extreme cooler) than the 6 gal batch (Gatorade 10 gal circular).

I have not done anything differently with my crush size (Barley Crusher) since my fly sparging days.  Mash temperatures have been hit perfectly (152 F), each with volumes of ~ 1.3 qts/lb, and mashes are all held for 1 hr. 

Process:
At the end of the mash, I slowly open the valve to set the bed, I recirculate until clear, and then crank wide open to drain.  I have calculated that based on where my Bazooka T is connected, I have about 1 gal of deadspace (with grain/solids in there, obviously that volume is lessened, but I would still think that 1/2 gal of wort is trapped in the cooler after each run-off).  After Run-off 1, I add essentially 1 gal more water than what I need to collect (to account for the deadspace) of near boiling water (200- 205 F) to raise the bed to 165-8, stir and wait for 30 mins, then repeat the slow drain, recirc and collect.

For example:
My first run-off on the last batch collected 7 gals (on 28 pounds) for the first run-off.  I added 6.5 gals of water, stirred, waited, etc.  Collected another 5.5 gals for my target of 12.5 gals in the kettle, and only got 56%.

I feel like the process is sound, but if I could guess what is wrong, I think it has to do with something in the second run-off, either the deadspace under the Bazooka T, or how much water is being added to collect the second run-off.  The second run with a 6 gal batch anf a different mash tun was higher (67%) but still not great.  The amount of deadspace in that cooler is much less.

I like the concept of batch sparging and want to get it right.  There has not been any issues with the taste of the beer (as one could expect), and in the grand scheme of things, I could just add another pound of malt to hit higher gravities.  However, I would like to maximize the efficiency of my system to at least 75% and be consistent with it.  Any thoughts would be appreciated.

[denny]

I think the problem is your 1 gal. deadspace.  If you're not draining that, you're losing wort.

[ynotbrusum]

+1 - I use a braid with a silicone insert to put it right on the bottom for a pickup point.  You will need to gather more wort, rather than further diluting it to gather more volume.  Perhaps tipping the tun toward the opening?

[HoosierBrew]

+1.  There's alot of sugar (ie., gravity points) in a gallon of wort. I prop up the end of my cooler with a piece of 2 x 4. For comparison, my deadspace is just under a quart.

[dmtaylor]

Don't waste wort.  Add exactly the amount of water you need to achieve your pre-boil volume, and collect every single drop from both the first and second runnings.  Tilt the mash tun to get every drop out.  Also run some calculations so that your first and second runnings are almost exactly equal volumes.  Then watch your efficiency hit the 80s.  If it doesn't hit the 80s, then you aren't crushing hard enough, plain and simple.

[a10t2]

For example:
My first run-off on the last batch collected 7 gals (on 28 pounds) for the first run-off.  I added 6.5 gals of water, stirred, waited, etc.  Collected another 5.5 gals for my target of 12.5 gals in the kettle, and only got 56%.

The large amount of deadspace definitely isn't doing you any favors, and neither is leaving an extra 1 gal of second runnings behind, but that isn't where you're losing most of your efficiency. The lauter efficiency for those numbers is ~75%, meaning that your conversion efficiency is ~75%. The first thing to do is look at getting that up. Crush, pH, temperature, and time.

FWIW, the lauter efficiency with no deadspace, equal runnings, and complete draining would be ~81%.

If it doesn't hit the 80s, then you aren't crushing hard enough, plain and simple.

Yes and no... It depends on how much you're willing to boil off. To get 80% efficiency on a 1.100 beer with a single batch sparge, for example, you have to reduce the wort by about 25%.

[benamcg]

Thanks for the input.  I used the tilt method and got the deadspace from 1 gal down to 24 fl. oz. I will report back after tomorrow's brew day if this cured the problem.  Thanks all!

[dmtaylor]

If it doesn't hit the 80s, then you aren't crushing hard enough, plain and simple.

Yes and no... It depends on how much you're willing to boil off. To get 80% efficiency on a 1.100 beer with a single batch sparge, for example, you have to reduce the wort by about 25%.

Good point.  I was referring to a more normal/average strength beer of around 1.050-1.065 gravity.  And of course you still need a decent sparge and hour-long boil to get 80%.  Cut any corners and efficiency goes down.

[benamcg]

I pretty much eliminated the deadspace, but still hit the same range of efficiency.  Probably even worse since I did not calculate in the contributions from the veggies (pumpkin).  All in all, not a good session to be trying to dial in the efficiency.

Other factors (too many variables are changing at once):
In this batch, my mash temp got too low due to adding the pumpkin mix (145).  I added a little more water (1 gal or 20% more than the target of 5 gals) to raise the temp bed (got it to 149). Also new, was a 90 min mash, but I doubt that it would affect the efficiency. 

Other than that, I took the advice of (nearly) splitting the run-off volumes evenly and only added sparge volumes that I was to collect for the second run-off.  I felt good about these improvements.  But alas, same end result.  I will keep fiddling to improve the efficiency, but, again, the simplicity and time savings of batch sparging make me not overly concerned- eventually I will figure out the system.

[stevek767]

benamcg,

I've only used the batch sparging method since I switched to all grain, and it did take me a while to dial in the process to get consistent efficiency every time (~75%).

I know that a lot of this has to do with your particular equipment, but it looks like you've got a similar setup and I'll tell you the things I did to try and help.

I'm not here to discount any of my fellow home brewers suggestions or tips, but deadspace and grain absorption are something we all account for in our particular systems and try to adjust for it when figuring our mash in and sparge volumes. Obviously, limiting the amount of deadspace is something that should be done, but is not something that can always be accomplished.

Here's what I have done:

1) I have my own cereal crusher and did have to adjust the gap down a little bit to get a slightly finer crush. I was using the "factory" setting when I first got it (I think it was at .042) and have now set it at .039".

2) I raised my water to grain ratio from 1.25 to 1.35 qt/lb. This made the mash thinner (obviously), but I think it mostly helps when I dough in. With the finer crush and the extra water, I find that the grains absorb the water more easily and allow more sugar conversion to happen.

3) After dough in, I stir the heck out of it. Now I'm not talking about madly beating and creating a frothy mess, I just take an extra few minutes to slowly stir and mix the grains into the water. I also do this after I add my sparge water in preparation for the second runnings.

4) I don't vorlauf. Now before anyone goes off on me, let me explain…I've found that, in my case, the methods I've tried to use in the past have not worked when I try to re-add the initial vorlauf runnings back onto the grain bed, too much grain bed disturbance for me. When I started to just empty the tun by filtering the wort thru a sanitized strainer/funnel, I found that I was getting a smoother draining process and after the first few quarts I was getting clear wort anyway.

5) Lastly, the only way you are going to be able to narrow down where your problem is specifically, is to take gravity readings thru-out the draining process. I do this by taking a refractometer reading every gallon while draining my tun. I record this in my brew log and compare it to my batch prep log. I do this thru-out the first and second runnings and am able to tell if I'm going to hit my target gravity and where my process has failed.

To get batch prep log expected gravity readings, you can use a couple of websites to determine what it should be. By entering your grain bill, batch size, and expected efficiency, you can calculate what your first and second gravity readings should be, as well as your target gravity for boil.

Here area couple of websites I've used in the past:

http://tastybrew.com/calculators/sparge.html

http://www.thebrewsite.com/batch-sparge/

I know there are more sites, but those are just a couple of the ones I use. Also, if you have any type of brewing software and have your equipment specs entered in, it should be able to give you those readings as well.

By incorporating these changes to my mashing process, I've been able to maintain a consistent efficiency and can identify when and if I'm going to have any problems with getting my target efficiency with a batch.

Hope this helps…


Steve

[a10t2]

What kind of efficiencies were you getting with fly sparging? Were they similar beers? Has the water source changed? What's your mash pH like?

As I posted before, most of your efficiency losses are in conversion, not lautering.

[HoosierBrew]

+1.   Be sure pH is good and double crush your grains and I bet you'll see a big efficiency bump.

[benamcg]

What kind of efficiencies were you getting with fly sparging? Were they similar beers? Has the water source changed? What's your mash pH like?

As I posted before, most of your efficiency losses are in conversion, not lautering.

Water hasnt changed.  I was getting 75% efficiencies with fly sparging

[ynotbrusum]

Hey Stevek767 -welcome to the forum!  That's a long post for your first one,and good points made, except on the Vorlauf, you may want to give it another try with a slower run off and slower pouring of the Vorlauf back into the mash tun...disturbing the top grains a little doesn't hurt as long as the lower few inches of the grain bed are set well.  Once it is running clear, you can pretty much let er rip. By the same token, as long as you aren't extracting husk material, your process should be fine.

To the OP - when I got my new grain mill I had to double crush or adjust the settings tighter to get the same conversion as my old one.  A really good stir eliminates doughballs, which can also affect your efficiency, but I suspect you are not allowing those to remain....

[stormtrooper]

It's been said many times, but indeed - use every bit of that precious wort and you may want to adjust your grain crush as you may not be getting everything out of it if it's too coarse. That's the simple bit to start with to see what that yields before going even further in.