View Full Version : Stuck run-off solutions

11-30-2006, 12:04 PM
I've been brewing on a 14-barrel JVNW system (built in 1993) for 10 months now, primarily making 7-barrel batches because that is the size of the serving tanks. I do brew a few beers (IPA, lager, wheat) in 14-barrel batches for efficiency. However, I dread making my IPA because the runoff invariably slows or gets stuck altogether, resulting in lower yields and long days. I don't have this problem with other 14-barrel batches.

I have around 1100 pounds of grain in the IPA and I think the additional weight makes the grain bed more susceptible to collapsing/compacting. I don't think it's the mill gap because other beers runoff just fine and the majority of the hulls are intact.

Does anyone have any suggestions for me regarding the runoff, i.e. how slow vorlauf should be, how slow should the runoff start and when do you speed it up, when do you start sparging, how much water should be on top of the grain bed during sparging...

Also, does anyone have a solution for a compacted grain bed? I can't underlet with anything more than a hot water hose, and that doesn't seem to help...

Here are some other details: the IPA mash is usually about 400 gallons at 152d, I vorlauf through a 11 gallon grant for 20-30 min (three or four grant cycles), runoff starts at 5 min grant cycles, I begin sparging when there is about 4" of water on top of the bed, sparge water is 165-170d. My 7-barrel batches take 80 min to runoff but I'm sure I could go faster. The other 14-barrel batches take around 2.5 hours.

Thanks for any suggestions!

11-30-2006, 12:53 PM
I'm not in exactly the same situation, but I have a 7bbl JVNW system. Just for comparisons sake, my 7bbl batches take 2.5-3 hours to runoff (approx. 1bbl of runoff every 15 minutes) , and I begin sparging with about 1-2 inches of water above the grain bed. I try and maintain the water depth at 1-2 inches above the grain.

When I've done half batches (3.5bbl) in my mash tun runoff usually takes about 1.5-2 hours.

Are you using any wheat or oats which might be gumming up the mash? Have you tried adding more hulls (rice or barley) to help?
Does the wort clear satisfactorily during the recirculation? Do you notice any grain particles clouding up the runoff when it begins to slow?

1100 lbs of grain for your IPA doesn't sound that big, I definitely squeeze 600+ lbs into my 7bbl mashtun without major problems...

just my 2 cents...

11-30-2006, 06:34 PM
Can you mash off in your mash tun. ie. raise entire temp to 76C. Helps with viscosity.

Also, when is the last time your lauter plates were acid washed. Loss of a thousandth of an inch in lauter plate gaps by scale build up can be significant factor.

Finally, there are a number of enzymes which can help you, all will be de- natured in the boil.

Good luck,



11-30-2006, 07:17 PM
Try using 25 lbs of rice hulls for the IPA. It makes a huge difference in the runoff.

Also try starting your runoff slower than normal, using gravity feed as long as possible. When the first wort is through the grain bed and the viscosity begins to thin, you can speed up the runoff greatly. But if you run off too fast in the beginning, you will compact the bed and will not be able to recover.

Are you cutting the bed? Try cutting the bed with a wooden paddle every twenty minute, cutting down to 4-6" above the false bottom.

12-01-2006, 05:46 AM
Another suggestion is to preheat your lauter tun with hot water so your mash when tranferring does not cool down and makes an easier lauter.

My two cents.


12-01-2006, 02:21 PM
Thanks for the suggestions fellas.
My mash tun is a combi tank so the wort goes directly from mash to kettle.
Vorlauf gets the wort as clean as other brews, but clarity does decrease when runoff slows.
I use rice hulls with my wheat beer and if my problems continue, I will probably try it with my IPA.
I do an acid wash on the plates approximately every 6 brews... I just cleaned them today and will be brewing IPA tomorrow, so we'll see if that helps.
I will try cutting the bed and running off very slowly at first until I begin my sparge.

Liam- What kind of enzymes would assist in the runoff process?

Thanks again guys, I will keep you posted.

12-02-2006, 03:04 PM
What kind of enzymes-

For mash viscosity issues, I would look at beta-glucanase, maybe cellulase, maybe endo-glucanase.

Lots of suppliers out there. Here's a good summary of types available and what they do.


Good luck.