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First lager brew - stuck fermentation?

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Muz

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Looking for some advice around my Munich Dunkel fermentation.

I haven't brewed a lager before and on the 20th of October I brewed this recipe:

https://byo.com/article/munich-dunkel-the-original-brown-lager-of-bavaria/

Brew day went really well. Mash temps were pretty well spot on and my OG was exactly to target.

I used yeast nutrient and aerated the wort using my drill paddle.

I pitched a large and healthy yeast starter.

Everything seemed pretty much perfect.

I fermented at 11 degrees for ten days then there was barely any airlock activity so a increased the temp for a diacetyl rest at 19 degrees.

Today I went out to start to slowly reduce the temp down for lagering and thought I better check the gravity. Expected FG is 1.007. It's at 1.024...

I really should have checked the gravity before increasing the temp but the airlock along with how well brew day went left me pretty confident.

Not being used to lagers should I give it more time? Try to rouse the yeast by shaking the fermenter? Increase the temp more?

Oh, I ended up subbing the yeast to. I used Wyeast 2308 Munich Lager as that's all I could get.

Thoughts from people who brew lagers?
 

cjpunk07

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I have a very similar problem, mine is stuck at 1.019. Not sure what to do.
 

Muz

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I'm working on a new theory for my problem. This isn't the first stuck fermentation I've had. I've had a few brews over the last two years that have finished 10-14 points too high. Something I considered stuck but I'm now thinking they're actually done.

I'm thinking the issue is mash Ph.

Until recently I didn't own a Ph meter. I managed my mash Ph the way I understand most people do. I build my beers in detail in BeerSmith and then I add whatever acid addition it recommends. From my understanding this is what most people do only they confirm the Ph after 15 mins of the mash. It's too late at this stage to adjust the Ph but they can at least confirm what they've hit and adjust for next time if out.

I've done two brews since buying a Ph meter and both have come in significantly under the 5.2 I was aiming for. One was 4.2 and the other 4.5. Not sure if it's BeerSmith, my water or what but it looks like I'm often if not always mashing with low Ph.

There are a couple of exbeeriments on Brulosophy where they adjust the mash Ph too low and they end up with with a much higher FG.

The good news is that people couldn't reliably tell these beers apart despite the high FG difference so all might not be lost.

Not sure if this is your problem but thought I'd add it in case anyone else comes across it. If you're doing everything else right (yeast starters, nailing mash temp, good fermentation temp control etc.) then it might be worth looking into Ph.
 

huez

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I'm not sure if it was something that i was doing but i never got the water tool in beersmith the work properly and then pH estimates were nowhere near what it was saying, it's seriously crap. Use something like bru'n water which is always pretty bang on, or switch to brewfather. Which is what i've done, it's always in the ball park and is more convenient than using 2 different programs.
 
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Muz

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Thanks. I've heard Bru'n water is good. It's just a spreadsheet yeah? Is it easy to use?
 

huez

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Thanks. I've heard Bru'n water is good. It's just a spreadsheet yeah? Is it easy to use?
Yeah just a spreadsheet. Initially a bit of a head scratch, but once set up it's pretty easy to put a recipe into it.
 

Sidney Harbour-Bridge

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I've always struggled with lagers, I only do them for the challenge, as I'm not mad keen on them. I wouldn't worry too much about the mash pH, I think mash temperature is much more important.

I've just had my best lager ferment, I put it down to mash schedule, I mashed in at 58 C and had a little protein rest at 54, this gives the beta-amylase the chance to do it's best, I raised the mash to 65 for 1 hour and mashed out at 77. Ended up with 28 L @ 1.054 in the fermenter, which was a bit more than the 25 L @ 1.045 I had planned.

I made a 4.5 L starter of W 45/70 which was dropped into the fermenter at 20 C and then cooled to 15 after 8 days it was down to 1.010, I put this down to the very fermentable wort.

Currently it's lagering and should be ready serve for works Christmas breakup.
 

razz

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Make sure you report back on how it turns out SH-B, sounds interesting.
 

Elmar

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Thanks. I've heard Bru'n water is good. It's just a spreadsheet yeah? Is it easy to use?
I'm using Brewfather as my brewing program.
I'm very happy with it. Does all the adjustments including water automatically for you. Worth a try.
Brewfather.app will get you there.
Cheers [emoji482][emoji481]
 

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