Slow run off and clumps in the kettle
Looking for some problem solving,
Our runoff time has dramatically increased recently (2+hrs for 16bbl.) and we are noticing clumps of what look like protein (tan gummy material) in the kettle. Our filtrations are slower than normal too. I've also noticed a grainy astringency(sp?) in our lighter beers. Opening or closing the mill doesn't seem to help. We just get lower or higher gravities with the same collapsed bed, slow runoffs, and clumps. Our mash ph's were high, so we adjusted down to 5.4 which increases to 5.9 in the last runnings. This seemed to help a little bit with the clumps and grainy flavor but not the runoff.
Is the grain the problem, the mill, grain auger (screw is starting to rub and put holes in the casing), etc.? Help.
Thanks for the help
Originally Posted by jbs
First, clumps where discussed on this forum more recently.
If the filter plugs up, I would think that you deal with protin materials.
The grainy astringency could come from the husk, especially if you mill to fine.
What is the pH of your sparge water? Are you treating your sparge water?
Did you used phosphoric acid to adjust your mash in water?
I observed that lighter beers, where mash in water and sparge water was treated with phosphoric acid had a grainy astringecy.
Lower final gravities mostly are a result from water treatment with acid.
If you wanna discuss the issue more, please give us some more details on malt, supplier etc.
Hope this helps for now.......
Thanks for the response. We are using Rahr 2-row. Our water treatment consists of CaCl2 and Lactic acid, both in the mash and in our sparge water. Also, we are using Fermcap in the kettle. And my malt screens tell me we are on the coarse side of text book spec. Thanks again.
Has your sparge liquor temp changed for the higher?
yes, sparge temp. up about 2 degrees to 170
Make sure the instruments you measure with are accurate. Have been fooled by this in the past--it's now the first thing I look for. Also, check that your grain has not gone slack (picked up moisture from somewhere). Good luck!
Excellent advice to check calibration on "trusty" thermometers. I try to get every one in the brewery done at least once a year.
Try knocking that sparge temp back down.
Have you changed the malt? Check out if the protein-content is not higher than 11%. What also can happened is the formation of ß-glucan-gel if the malt was not treated correctly and has allready to much of the ß-glucan-precurser. If it is the ß-glucan, you have to head the beer up before filtration or what is better to use the enzym ß-glucanase. Good luck
You have described a lot of symptoms that can be from a whole lot of sources.
“We just get lower or higher gravities with the same collapsed bed, slow runoffs, and clumps.”
If your lautering is “collapsing” (which I am assuming is you attain clear wort but then go to a starch, husk and hazy mess later), then you need to work on correcting this first. This is because all the problems you have described can be caused by poor lautering. Fix the lautering and many could go away and then work on the remaining which could be from many of the other factors.
Can you clarify what you define as collapsing and whether or not you are collapsing every run?
I'm lautering slow enough to not collapse my bed fully. The problem is I have to runoff way slower than I used to in order to maintain a clear wort and an unstuck mash. Although, the grain bed does drop more than I like. I believe, if I lautered like I used to, I would get a stuck mash everytime. Also, I have noticed mud on top of my bed and have been raking it as I runoff.
What is so frustrating to me is that I have what looks like clear wort and a good ph, but still have strange clumps in my kettle and difficult filtrations. Thanks everyone for your help.
Your condition sounds exactly like what I've seen in starting up our 15 Bbl steam system. I'm probably going to mirror the comments of others but here's what our impression was and what we witnessed:
1.) We had a tight milling of the grain as we were still setting the mill roller gaps. A little too much flour was created.
2.) Dough in was fine. We run filtered water and add minerals mix with water to the foundation water as the grains are coming in.
3.) Mashing was fine.
4.) Re-circ went OK. It took a while to get clearer results and flow slowed considerably.
5.) Lauter stuck very early on, and we had to underlet to float the bed up to set it again. Due to the fine flour nature of a portion of the mash, the grant looked almost like a big pot of miso soup!
6.) We ended up collapsing the bed since we were still gaging the system and ran out of fluid in the bed but still needed more in the kettle. We restarted the sparge on a dry bed and brought a lot of crap over to the kettle.
7.) We skimmed off protiens for days, it seemed, and wer still skimming into the boil.
8.) At whirlpool after boil, we saw "cheeselike" clumps of proteins in the wort that were solid enough to skim out in a rapidly moving whirlpool. Since we were making a light all 2-row pale malt batch for our shakedown, these clumps were yellowish/gray in color. I have never seen these before in our direct fire system.
Just some humble recommendations:
- Check your mill gap and look at your cracked grains up close. You should be getting 1/3 grist, 1/3 husk, and 1/3 flour for max extract. The husks should be whole and not sliced up. Nearly all mash/sparge/extract problems I've seen in our process stem from the mill settings.
- Try and keep the bed wet and suspended at all times. A collapsed bed produces a "hydraulic lock" due to the pressure differentials between the top of the bed, where the water is pressing down, and the underlet, where there is a vaccum created by the draining of the wort. This just makes the problem worse and will shut down the flow through the bed altogether quite quickly and without any fanfare, I might add.
- Run your sparge at the right temps or a snick warmer (170F - 176F). Some will say you're drawing tannins. I've never tasted that in any of our beers, but a cold sparge will lock things up a bit as well. Resist bringing anything cloudy over to the kettle. If you have to, re-set the bed with another re-circ step.
Try throwing some rice hulls in your mash to keep it loose. You shouldn't need to, but it may make your life easier until your problem is found and corrected.
How is your foremasher? Sometimes when mine sits a bit cock-eyed it gives uneven wetting of the grist and all sorts of things go wrong.
Is it possible the pH or mineral composition of your water supply has changed? Sometimes municipalities grossly alter their water suplies and (of course) don't tell anyone.
Last edited by Moonlight; 10-12-2005 at 10:25 AM.
1/3 Flour? are you crazy?
Originally Posted by Diamond Knot
1/3 flour is nuts! you should have little or no flour in your grist. whole endosperm chunks are ideal (3-4 per) unless you have a mash filter, or a very, very nice rake system in your lauter.
Wow, Larry.........could you sugar coat it a bit?
That's recommended from several sources.
Wondering if there is a problem with the grain handling system after milling. If your sieve test shows consistent analysis with prior tests maybe you can perform a sieve test down stream of the mill to determine if you grist is getting beat up by your auger transfer system. If the percentage of flour greatly increases perhaps you need to tighten up the coil or slow down the infeed to the auger. I've seen auger coil(s) do alot of damage to grist on the way to the grist bin at several breweries.