Since Getting New Equipment, Beer Keeps Stalling, Please Help!

[Bramstoker17]

Hey everyone!

I'm getting incredibly frustrated with a recurring problem where my beers are all stalling out way early, usually somewhere around the 1.020 mark. I've had a beer with an OG of 1.060 stall around there, a beer around 1.044 stall there, and several others. Some background to help diagnose the problem.

I've been brewing all grain for years doing a 2 kettle BIAB system where I mash with the normal volume of water, then have the sparge volume in another kettle and move the bag over to that one. I combined kettles, boiled, used an immersion chiller, and then aerated by shaking. I usually use Imperial Organic yeast and they don't recommend making starters with their cans so I never did. I NEVER had a stuck fermentation with this method.

A few friends who were interested in getting into the hobby and I sprung for a more sophisticated set up. I now have a three vessel stainless steel 20 gallon Mega Pot system. I do 12 gallon batches in it. I fly sparge, pump my beer from vessel to vessel, I have a plate chiller, and I use an oxygen wand to oxygenate my wort.

I've done about 4 batches on this set up now, An IPA, a DIPA, a blonde and a Kolsch. Each beer has stalled out on me. I've used Imperial Yeast as I always have. At first I thougt I oxygenated wrong since I had never used a wand before. The first batch I did 45 seconds, but I realized I did it too hard. The beer stalled. The next one I did it for 30 at a reasonable rate. The beer stalled. I wondered if I was over-oxygenating so I did 20 seconds the next time. The beer stalled. I realized I was probably under-oxygenating after doing some more reading so for my last batch, the Kolsch, I did a low flow rate for 2 minutes prior to pitching. The beer foamed up a ton so I can't imagine there wasn't enough O2 in there. I checked the beer after a week and a half and its stalled.

I checked my Thermopen to make sure it wasn't off and it was all good. I checked my hydrometer and refractometer and they are good. I did change my water to Primo water from Walmart, but its supposed to be like RO water from what I've read and I use minerals to adjust. I also switched to lactic acid rather than acid malt to control mash Ph. I only add salts and acid to my mash or in the boil kettle, I've never added anything to the HLT for sparging.

I have no idea what could be causing this to happen. Its only since switching to my new system that I've been having this problem and its getting so very frustrating! Any ideas what could be going on here?

 

[Transamguy77]

I see that you said you have checked your hydrometer and refractometer so I have to ask, are you checking your final gravity with your refractometer?

If you are doing batches that big I'm assuming you are splitting them into 2 fermenters, are you making a starter or pitching multiple yeast packs? 6 gallons is a lot of beer for 1 smack pack.

 

[chickypad]

Is this a recirculating mash or what is your setup? 12 gal is a fairly big batch, if the thermapen is your only thermometer wondering if you have hot spots and are mashing higher than you think. Seems the most likely explanation if you had no troubles with yeast performance before and this suddenly happened with the mash equipment change.

Edit: good point above, this is assuming you also increased your yeast proportionately to the larger batch size

 

[Bramstoker17]

Thanks for the replies! I split the batch into 2 fermenters. Each fermenter gets a can of yeast for a normal mid gravity batch. Imperial makes their yeast cans ready to pitch with 200 billion cells, so I don't think that's the problem. I also check fg with my hydrometer so I'm good there

Chickypad, the hotspot thing is interesting and a possibility. I heat my mash water in the mash tun then stir my grain in. I give it a stir every 20 minutes, and then mash out and vorlauf. I'm not setup for a constant recirculating mash. I do have a mash tun thermometer. It's read higher than my thermopen before during the mash, but I stir quite a bit. Still, this is a good place to start. I'll make sure it's calibrated and pay very close attention to both thermometers next batch. I know last batch I was stirring and I bumped the probe in the kettle and the temp instantly jumped about 5 degrees up. I'm not sure how accurate it is, but maybe that's the issue since I can't imagine what else it could be.

Still, like I said this was never an issue before. Does the increased batch size make even mash temp distribution that much more difficult?

 

[chickypad]

I think big mashes hold temp better, but yeah it's a lot of volume to stir initially to get it uniform. I've always recirculated with big batches so haven't noted that problem but it seems plausible. I'd definitely calibrate your tun thermometer and see what the center is measuring.

 

[TungstenBeer]

Hi Bram,

You had a whole paragraph about O2 in the OP... I would probably get off of that, I really doubt that's at all related to your issue.

I would agree with the potential hot spots in the mash. If that's not it, perhaps it's your fermentation setup? I assume that it's the same process, so probably not the culprit, but it's hard to say. What's your process on the cold side?

 

[Bramstoker17]

I have a temp controlled fridge. I usually ferment around 65 to 68 and keep the temp consistent within a couple degrees. After eliminating O2 issues it has to be something with my mash process.you guys are probably right about the hot spots