low brewhouse efficiency

[wagesgt903]

So this is probably the 3rd all grain batch on my new system and I can't seem to get my efficiency above about 64%. Did a rye IPA batch last night which didn't notice till after but the recipe was at a 78% efficiency so I shot low on my starting gravity. I am using a fly sparge for my system and the temp in my cooler mash tun was right at 153.





My question is how long does it take you guys to sparge into the boil pot and can going to fast affect it that much?

Here is a pic of my system

 

[Glynn]

I have tried both methods of sparging and for me it made absolutely no difference. I only batch sparge now and routinely hit 80% mash eff. to answer your question when fly sparging it should take a long time, about an hour. do you crush your own grains?

 

[wagesgt903]

No the store here does the grain for me. The time is probably my issue. Maybe took 25 min to sparge to my 6.5 gallons for boil.

 

[Glynn]

your hbs is most likely the suspect. Check there gap with a credit card if its bigger then that it might explain the low brewhouse eff. before i got my mill i always had a 64% brewhouse. now my brewhouse is 75%

 

[wagesgt903]

As in they are not milling the grain fine enough?
Should I still slow the sparge rate down?

 

[Glynn]

Yes to both

 

[EarlyAmateurZymurgist]

When using traditional (a.k.a. continuous or "fly") sparging, it helps to raise the mash bed to between 160F and 168F via a mash-out infusion of boiling water before sparging. Additionally, you should shoot to collect a gallon of runoff every 7 to 8 minutes until you become familiar with your setup. You will eventually find its sweet spot.

With that said, mash tun design plays a bigger role in the outcome of a continuous sparge than it does in the outcome of a batch sparge. What are you using for a false bottom?

Could post a photo of your grist? The proper crush for continuous sparging is different than the proper crush for batch sparging.

My mill is permanently set at 45 thousandths of an inch. The non-embossed portion of a credit card will easily pass through my mill (most credit cards are 30 thousandths of an inch thick). However, my average mixed-grist extraction rates are 30 points per pound per gallon with domestic malt and 32 points per pound per gallon with imported malt (both of which are well over 80% considering that they are mixed-grist, not base malt extraction rates). The relatively coarse crush that get with my mill leaves more of the husk intact, which improves the permeability of the mash bed. Uneven permeability is not that big of an issue with batch sparging because the sugars are stirred into suspension. With continuous sparging, the sparge water has to flow evenly through the entire mash bed in order to achieve high extraction rates.

Finally, did you ensure that there were no dough balls in your mash?

 

[iijakii]

What kettle is that? That's incredibly narrow and awesome.

 

[Hamaki]

What was your recipe? Temperature & qts/lb of strike water? Incomplete gelatinization, possibly dough balls, could be a factor. So could short circuiting in a continuous sparge. A false bottom or a well designed manifold would help on that as would a relatively deep grainbed. It took several batches & a change of equipment before I began to achieve good utilization of my malt. I can remember more than one occasion dumping my rectangular cooler MLT after a brew session only to find bone-dry clumps of grain in the corners.

 

[wagesgt903]

As far as the grain used the next batch I do I'll post a pic and get opinions. I don't have any left from the last batch. I have been using 1.25 quarts per gallon and mashing in at about 172 degrees which puts me usually between 152-154 in the mash run. I add the grain in about 2 pound increments and stir to make sure there are no clumps. Sparging at about 170 degrees. The cooler has a stainless false bottom and a bazooka braided tube attached below that. Probably overkill but I get no grain into the boil pot.

 

[Hamaki]

What was the grain bill in your last batch? Did you add rice hulls to avoid lautering problems with the rye?

You might consider batch sparging next go around to see if efficiency is improved. If so, and especially if you're able to repeat the performance with another batch sparged session, it's likely an issue with continuous sparge. That could mean over extraction (possibly including tannins) of some portions of the grain bed and little or no extraction from other areas.

If you still get low efficiency it's not necessarily that bad a thing. You might spend a few more dollars per brew session but you can anticipate the result. Higher but variable efficiencies that are unpredictable from one batch to the next make it harder to reliably hit your target.

 

[wagesgt903]

11lbs american pale 2 row
3lbs american rye
1lb caramel/crystal 60l
.5lb carapils

I was supposed to have a half pound of rice hulls but had a brain fart and forgot to mix them in.

 

[Hamaki]

Assuming the LHBS grind was somewhat coarse it probably helped avoid a completely stuck mash with the rye and no rice hulls. What often I see in my MLT when draining first runnings or a batch sparge is that, no matter how careful I am pouring vorlauf wort back into the tun, I still churn a low spot at the edge of the grain bed and flow seems to prefer this path around the edge of my false bottom. This is very noticeable on wheat beers (I've not used rye) that produce a fine, less freely draining, layer on top. First runnings are no problem and, for me, the batch sparge is also thoroughly mixed and I'm only draining. I don't have a pump to recirculate. If this kind of channeling happens during a fly sparge it could make a difference.

Looks like yours is a gravity setup as well. Might take a close look at what happens to your grain bed if you vorlauf like me - pouring the wort slowly down the side of the tun to minimize disturbance to the bed still doesn't leave the bed an intact and uniform filter in my setup.

 

[Bsquared]

In my experience a sparge rate for continuous sparge of 1 liter/min (1pint/min) is what most literature states. I have a lot of trouble getting my flow rate down to 1 liter/min, and usually settle for about 2 liters/min. I see ~75% efficiency with 2 liters/min and 85% with 1 liter/min. When doing a continuous sparge too, it is important NOT to drain the first runnings below the grain bed before starting to sparge. Ideally you will drain the first running until you have ~1/2" of wort covering the grain bed then start the sparge water maintaining ~2" of water above the grain bed. The sparge water will float on top of the more dense wort (like Bass floats on top of a Guinness in a black and tan) and the weight of the sparge water will act like a plunger and push out the high gravity runnings. Then as the sparge water filters through the grain bed it will dissolve the remaining extract and transport it to your kettle. If this part of the process is rushed you will leave a lot of extract in the grain. Also you might want to just use the false bottom alone, it is very important with continuous sparging to get an even flow through the grain bed, and this is best achieved by using a false bottom alone.

 

[wagesgt903]

Brewed yesterday and tried a couple little changes. Added some pH 5.2 stabilizer to the mash and slowed the sparge way down. Needless to say 15 lbs of grain ended up with a 1.074. I know its a lot better just have to calculate the actual efficiency.

 

[Hamaki]

Looks like around 73 - 74%, assuming a similar list of malts used for your last batch.

 

[wagesgt903]

This was the grain bill