Sticking sparge

[DancingCamel]

Last few brews we've been consistently sticking the sparge on our IPA. I'm baffled because we don't have a prob with Vorlauf - sticks only about 10 minutes into sparge. Other particulars - 340 kg grain bill, dough-in with 200 gallons water, sach rest at 150 for app. 1 hour. Vorlauf for app. 20-30 min during which time probe temp drops from 150 to ~145. We time our sparge for about 90 minutes so I don't think we're running off too fast. We don't have a problem on any of our other beers, though this is the biggest grain bill by app. 40 kg. This is also our thickest mash. Sparge liquor comes in at about 172.

This is the third time it's happening so...help?

David

[GlacierBrewing]

Hi David,
Just to throw a few ideas out there:
Could be with the increased grain bill and associated increase weight, your run-off speed could be too fast thereby sucking your grain bed onto the screens. I was having a similar issue with one of my brews. I "solved" it by slowing down the run-off and gently stirring the mash during the sparge. I wouldn't stir all the way down to the screens but close. Also, I'd monitor the thickness of the bottom of the bed by gently pushing my paddle to the screens. I know there are those brewers out there that are spitting their coffee or beer across the room as they read this and screaming "NEVER STIR THE MASH DURING THE SPARGE!". Well, this worked for me and the final product is no worse for the wear.
Prost!
Dave

[pennbrew2]

I know there are those brewers out there that are spitting their coffee or beer across the room as they read this and screaming "NEVER STIR THE MASH DURING THE SPARGE!".

If so, then they'd be wrong.

[canyon]

Do you have the capability to heat the mash(steam jacket etc.)? What kind of false bottom to you have? Not that stirring during sparging is wrong, but I prefer to slice channels 2/3 of depth without stirring just cutting. Getting the temp up can make all the difference. You can roust with boiling water prior to vorlauf if that is your only option. You can start with much hotter sparge water (even boiling) for the beginning and then drop the s.w. temp as you go. Monitor the temp of the top few inches of mash so you don't overheat for unwanted compound extraction. Or even do a decoction.

[Woolsocks]

I've had sticking issues when running directly into a pump rather than into a grant. If the pump is sucking too hard, harder than gravity alone would do, it will tend to stick.

If nothing else, stir in some rice hulls!

[DancingCamel]

Hey - thanks for all the feedback. We do runoff to a grant so at least that's not the problem. Our MT isn't jacketed so I can't just flip the switch to apply heat. We do cut the bed about 3/4 of the way down. Rice hulls aren't available here (or at least I haven't found them) and importing isn't an easy option.

I'm really thinking about the temp drop during vorlauf and getting a crazy idea to vorlauf through a copper heating coil (MT to grant through coil and back to MT) so that I can apply heat as I'm vorlaufing and not lose temp. (Think back to your first RIMs system) We could even mash out this way which we don't currently do. Added advantage is that we can step mash without additonal infusions using the same system.

Any reason not to do it (other than I don't have the time to set it up)?

Thanks.

David

[canyon]

Heating recirc wort

Copper coils can work but are difficult to clean with wort flowing through and can add wanted or unwanted house character after only a few batches of use. With stainless you can more easily circulate cleaning solutions through although it will take more length of tubing due to less efficient heat conduction. After three batches on a copper coil I made, I upgraded to a stainless coil in direct fire (propane) and was surprised at how little temp gain I got and had to add more loops.

[Michael Murphy]

David,
You are using a single step correct?... 99 times out of 100 its your mill... I learned this after many times of stuk mashes. I've been through periods of thought where I thought it was from too much use of dark malts, or heavy mash load / brew size etc... When the milling is wrong it gets stuck within the first 20% of the runoff. I'd seriously look at your milling. open it up and start to find the right setting.


Stuck lauter = shitty brew day

[DancingCamel]

Hey Mike -

Good to hear from you. Sticking the runoff started happening when we decided to remeasure our sight glasses to see what we were really getting into the fermenter. Guess what - they were all off by app. 8-10%. So we adjusted our recipes which meant adding more grain and that's when the problem started with the IPA. I would agree that the mill would be my first likely suspect (plus I just like blaming the mill-it's an ugly little bugger that sits in a dark, windowless room) but I don't think it was responsible this time. Unless you're suggesting that I should adjust the mill if my grain bill's gone up??

D

[Valleybrew]

How similar to your Vorlauf flow is your first run off flow? I have found my self running a nice slow vorlauf and then when I switch to wort transfer to the kettle, speeding up my pump and ending up with a stuck run off 10 or 15 minutes into the process. I now have made a conscious effort to set the Vorlauf flow rate and keep it that way a good 30 minutes into run off. It added about a half hour to my sparge but I haven't seen any stuck sparges in awhile. Checking your mill grind profile is also a good idea, as you added more malt to the recipe you may have to change the grind slightly to compensate for the larger mass in the MT.

[Michael Murphy]

You shouldnt have to adjust the mill gap to use more grist that would defeat the purpose of upping the malt bill. But if your lauter is sticking occasionally you should have a look.
I always have found the mill to be the culprit in stuck lauters on single step systems... If you are stiring the mash the whole time or aerating or sending alot of flour under the false bottom thats a process issue you should address.
Adding up to 400 lbs for a 1000 lt brew isnt unheard of either.
Slow runnoffs stick too, I would open the mill a bit make sure the crush looks good and see what you get on the % eff.

Good luck

[enickohasan]

Out IPA was causing some slow runoffs. To fix the problem we used more water during mash in. We used to run pretty thick, and this helped runoffs immensely. We also sparge for a few minutes before we start runoff. We haven't had any problems since then.

After we fixed that problem, I looked at our malt specs. We were using 2-row malt from Rahr and the beta glucan content seemed kind of high. We switched to Rahr Pale Ale malt with a lower glucan content and lautering for all of our beers has been a dream ever since.

Sorry to dredge up an older thread. I'm kind of behind on reading the forums.

[SRB]

Sorry to dredge up an older thread.

I say dredge away!
for us today...Batch 5.... Stuck mash. underlet and stirred. no bueno. day ended allright. On the other side of the window its Day 6 open and the pub has been slammin'...much beer is flowing. many, many happy people.
so thats nice

[beermkr]

I would say that it is a weight of grain issue and I agree with someone above to increase your strike water volume. Make it a little runnier so that the vorlauff makes a gentler bed. I think you are creating a dense filter bed and maiking it through the recirc only to fill in the holes during runoff. I would also slow down my runoff. My big beers always took a significantly longer time to runoff.

Mike

[wiredgourmet]

Mill gap, mash liquid/solid ratio, husks, temperature, glucans, all relevant factors and worth checking.

One thing frequently overlooked, hinted by Michael, is pH. If it gets too low, the grist turns to mush.