Latest Lager Redux - what I have learned.

After 6-7 lagers, I am determined to brew one that actually tastes "lagery" and doesn't take a dang week to get going.

So, this time, I did it by the book, and for the first time I had a vigorous fermentation going, at target temp, in less than 48 hours. I may be jumping the gun on this, but I call that a preliminary success. Here's a breakdown of what I did differently.

1. Temperature

Previously I had to crank my fridge temp up to the 60-70 range for a few days to get the yeast started, even with a starter. After cooling the wort, I put the temp controller all the way down to 45 for this, taped the probe to the side of the carboy, and waited several hours for the wort to come down to pitching temperature.

2. Aeration

Previously I would depend on the "splash the wort" and "shake the hell out of the carboy" methods for aeration. Not this time. I went whole-hog on this one. Bought me an aeration stone and filter assembly from the LHBS, then dropped by the local welding shop, where they hooked me up with the regulator and fittings to hook the assembly up to a 20-pound oxygen tank. Gave me a pretty hefty discount, too, since I was a homebrewer and not a welder (apparently homebrewers drive a large chunk of their business lately).

I boiled the aeration stone and tubing for 15 minutes, hooked it up to the filter already plugged into the O2 tank, and cranked it up. Had a slight mishap where I opened the main valve too far and spilled some wort over the sides of the carboy. Despite some fussing, I couldn't manage to get a gentle flow with the main valve all the way open, so I ended up cranking the main valve slightly, and let it bubble for 2 minutes.

3. Cell count

I said "Screw it" to liquid yeast and attempting to build up a starter. Too many headaches and heartbreaks (I have one lager that tastes like a too-fruity Belgian because I forgot to decant the starter before pitching).

Since I was preparing mason jars to wash the cake from a previous brew, I set aside one jar with boiled, chilled water, dumped off about 1/8 of the water, added 2 packets of Saflager W-34/70, and let soak for about 7 hours prior to pitching. After chilling and aerating, I gave the whole thing a good shake and dumped it in, water and all.

The Result

Within 24 hours of pitching there was a thin yeast layer on top of the wort already. 48 hours later there was a thick, healthy layer of krausen on my lager, big enough to compete with some of my pale ales. At 45 degrees, no less. All my previous lagers would sit, flaccid and motionless, for at least a week before showing any sign of fermentation.

The Moral

If in doubt, check your process. Also, and this is something I didn't pick up on when I first started doing lagers, but aeration is at least as important to lager brewing, if not more so, than temperature. Just having a freezer and a temp controller isn't going to brew you the best lagers. Shaking the hell out of the wort is fine for ales, but it will only do so much for lagers. Having some method of active aeration is as crucial. If you're gonna drop $100-200 on a freezer setup to do lagers, you might as well splurge on oxygen as well.

The hard part now is going to be waiting the 10-14 weeks before I can actually taste the final product!

Glad to hear you had a good experience. Two packs of 34/70 = good. Aerating with pure O2 = good.

Not following manufacturer's instructions on how to rehydrate yeast = bad, but not bad enough (this time) to cause you any trouble.

Great job!

osagedr said:

Glad to hear you had a good experience. Two packs of 34/70 = good. Aerating with pure O2 = good.

Not following manufacturer's instructions on how to rehydrate yeast = bad, but not bad enough (this time) to cause you any trouble.

Great job!

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Man, I'm never organized enough to do everything right. Plus I'm usually in a mild panic getting everything together to finish off the brew day by chilling time, so I doubt I'd have remembered to rehydrate 30 minutes in advance...

How bad is rehydrating 7 hours in advance versus half an hour?

Well it sounds like your process is good, and improving.

I don't know enough about yeast to know how bad it is to rehydrate that far ahead of time, but given how well your fermentation is going, it can't be that bad. Someone who knows a lot more than me might be able to give a good technical explanation. It might be one of those deals where it will work 19 times out 20 but then one time something will go awry.

One thing on the O2; I've read that you can actually over-aerate the beer so pay some attention to that. Paradoxically (seemingly), I've also read that giving another shot of O2 after fermentation is evident is also a good idea. Other than having to re-sanitize stuff (like you when I first started aerating I boiled my stone, now I just soak it in Starsan), this doesn't take much time and likely helps fermentation. I haven't done a second round of O2 yet but will with my next lager.

well ill be giving it a go this sunday without an aeration stone and with liquid yeast. starting my starter tonight and plan on having around 400 billion cells at pitching time. we'lll see how that goes. good to hear your brew is doing well!

nootay said:

well ill be giving it a go this sunday without an aeration stone and with liquid yeast. starting my starter tonight and plan on having around 400 billion cells at pitching time. we'lll see how that goes. good to hear your brew is doing well!

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I can only hope your experience is better than mine. If you're not aerating, I'd recommend starting at 60 degrees and dropping down to 45-50 at the first visible sign of fermentation. Be sure to do a proper diacetyl rest if you do this.

i plan on shaking it for a good 5 minutes straight, but i do think pitching at 60 is a good idea.

nootay said:

i plan on shaking it for a good 5 minutes straight, but i do think pitching at 60 is a good idea.

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I forget where I read this, but I believe you can get around 6-7% aeration by shaking. With pure O2 supposedly you can get something like 20% aeration.

What you are looking for is parts per million (ppm) of O2. You can get around 8 by shaking or running air through an aquarium pump, but according to Wyeast you need at least 10, and often more, which can be accomplished with pure O2 through a stone.

http://www.wyeastlab.com/hb_oxygenation.cfm

I can tell you I noticed a much more vigorous fermentation with my lagers after I started to aerate with pure O2.

Osagedr, do you aerate your ales as well? What effect does that have on your final product?

I have no experience with final product after 02 aeration, but my last two brews (ales) I used my new O2 stone and they took off like rockets within hours. The blow off wouldn't stop for over a day. I've had vigorous fermentations before, but these two just seemed above normal.

bernerbrau said:

Osagedr, do you aerate your ales as well? What effect does that have on your final product?

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I do aerate my ales. I've never done a split batch with and without aeration to assess impact on the finished beer. My belief based on what I have read is that getting the recommended PPM of O2 into my beer will create optimal conditions for yeast growth, and as a result a healthy fermentation.

I have read at least one thread on HBT where a brewer swore they tasted a big difference in their finished beer after they started aerating with O2.

osagedr said:

I do aerate my ales. I've never done a split batch with and without aeration to assess impact on the finished beer. My belief based on what I have read is that getting the recommended PPM of O2 into my beer will create optimal conditions for yeast growth, and as a result a healthy fermentation.

I have read at least one thread on HBT where a brewer swore they tasted a big difference in their finished beer after they started aerating with O2.

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Sounds good. Can't wait to get an APA or IPA going with the O2 stone.

The colder your wort, the more O2 it can grab.

Nice. Does mg/L translate directly to PPM? And can we assume wort would have the same oxygen soluability as water? If the answer to both of those is yes, then can we get no more than 9 PPM at 70 degrees (20 Celcius)? I'm uneasy with that.

That chart is missing a pressure, or rather partial pressure indication. As the partial pressure goes up (in the case of O2 stone, considerably) so will your solubility. The affect will be the same as CO2 in your beer. At room temp, it isn't in equilibrium which is why it bubbles, but this happens slowly without an event to propogate it. The same will be true for your oxygenation. You are getting greater than this chart with an O2 stone, but probably not much since the contact time is short. Partial Pressure is Ptot*mol%. So for us lowely shakers it's 1atm*.2 = .2atm. Your feed with O2 stone is going to be a partial pressure of whatever your outlet is. The relationship isn't linear, but you're going to get significantly greater solubility.

And yes, mg/L = ppm

Thanks for the technical explanation. I've seen references to 20 or more PPM but maybe that's just with brewery-grade equipment?

My take-home message from this thread and a bit of other reading on the topic today is that it's virtually impossible to over-aerate your wort with pure O2 at the start of fermentation. I had been wondering about the 60 second rule-of-thumb. Now the question is how much O2 to "waste" trying to get those PPM up given the max soluability people are referring to at the pressure homebrewing O2 systems can deliver.

osagedr said:

Thanks for the technical explanation. I've seen references to 20 or more PPM but maybe that's just with brewery-grade equipment?

My take-home message from this thread and a bit of other reading on the topic today is that it's virtually impossible to over-aerate your wort with pure O2 at the start of fermentation. I had been wondering about the 60 second rule-of-thumb. Now the question is how much O2 to "waste" trying to get those PPM up given the max soluability people are referring to at the pressure homebrewing O2 systems can deliver.

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Every thread I have read is to turn the O2 on until you just see it bubbling on the surface. 45 to 60 seconds of this is the local advice.

Also, Osage, can you explain your comment further that it is virtually impossible to over-aerate your wort? I have heard that this is possible with pure o2 and to avoid it (regardless of the fact that we have no way to measure if it is or not).

TheMan said:

Every thread I have read is to turn the O2 on until you just see it bubbling on the surface. 45 to 60 seconds of this is the local advice.

Also, Osage, can you explain your comment further that it is virtually impossible to over-aerate your wort? I have heard that this is possible with pure o2 and to avoid it (regardless of the fact that we have no way to measure if it is or not).

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What I read in multiple locations (I didn't keep the links but will see if I can find one or two) is that any excess O2 would dissipate and that the yeast would use all available O2 in the first half a day or so after fermentation begins.

Also if you look at the soluability chart provided by 944play, it looks like it's difficult to get more than 10 or 12 PPM into your wort, even at lager pitching temps. So how would you over-oxygenate, given that you see recommended PPM of up to 26 for big beers? Certainly 20 PPM would never hurt any beer (10 PPM is the minimum recommended), and it looks like it would be difficult for homebrewers to even get to 20 PPM given our rather low-tech oxygen delivery methods. So that's why I have this impression that over-aerating would be virtually impossible.

The chart is great but one thing is says to me is that lagering at a temperature in the low 50s, which is the comfort level for most lager yeasts, is not too significantly different from lagering in the mid-40s. My experience has been that when I go lower than 50F I have seriously delayed fermentations that always worry me (but should not.)

maltoftheearth said:

The chart is great but one thing is says to me is that lagering at a temperature in the low 50s, which is the comfort level for most lager yeasts, is not too significantly different from lagering in the mid-40s. My experience has been that when I go lower than 50F I have seriously delayed fermentations that always worry me (but should not.)

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To be clear, the "lagering" period is the cold storage period (closer to 32F the better), not the fermentation period.

It can be nerve-wracking to wait for lager fermentations to start, but if you create good conditions for your yeast and pitch enough of them, they always figure out what to do. I also think AG fermentations go a lot better for lagers than extract fermentations.

I now regularly pitch at 43-44, then let the wort warm up to 45-46 for fermentation. It might take 36-48 hours to see much activity, but it always comes. I now regularly use two packs of dry lager yeast rehydrated, or repitch 1 to 1.5 cups of slurry depending on the gravity of the beer I'm starting.

Right now I have a Bohemian pilsener going into which I pitched two packs of S-23 rehydrated. The yeast are working hard at 45 degrees. After pitching Saturday night I saw activity Monday; OG was 1.052 and today I measured it at 1.036 which tells me things are moving along nice and slowly. Likely take it out of the chamber for d-rest this weekend sometime.

Can't wait for my S-189 to arrive from American Brewmaster!

What's your experience with S-23? I've heard horror stories.

I've only used S-23 one time previous to this. It was in another Bohemian lager, and I went warm on the fermentation (56 ambient, so high-50s ferm temp) based on internet warnings regarding its fruitiness (especially from Denny; I figure anyone who has a yeast strain named after them should be taken seriously!). The lager turned out very well IMO; not fruity at all.

This time I decided to go cold on the ferm to find out for myself whether the fruitiness is as bad as others have said. We'll see what happens. It's not a yeast I plan to use a lot in the future; but there are probably a few lager styles it's perfect for. It's the only dry lager strain my LHBS carries (but they usually have a very good supply of Wyeast products).

Since this has been an outstandingly successful lager fermentation, would there be any problem taking the beer up to 62 at this point for the D-rest?

If you have reached FG, it may be too late for a d-rest. You also may not need one. You won't hurt anything by raising the temp to 62 unless you are still early enough in the fermentation process to affect the flavour profile, which I don't think is true in your case.

You want to do your d-rest when you are about 3/4 of the way to FG. For most of my lagers that's around 1.020 or a hair under (i.e. 1.050 - 1.010 = 40 gravity points, so d-rest at 1.020). For bigger lagers it could be considerably higher (i.e. suppose your doppelbock OG was 1.088 and you expected FG of 1.024; 3/4 of 64 gravity points would mean starting your d-rest at 1.040, although to be honest in that case I probably would do it in the low or mid 1.030s). I plan to do a doppelbock right away so I will have to give that more thought!

There's still a krausen on it (at least there was last night). When I get home I'll grab a hydro sample and see how close to finishing out it is. If it's around 20 I'll crank it up.

Well, the reading is 1.039 - which is weird because I was targeting that for my OG. I did under-sparge, and maybe I got higher efficiency than I was planning. Wish I had done a hydro reading up front. Krausen is still pretty high, yeast is pretty thick in suspension and there are still a lot of bubbles from the blow-off tube.

It positively reeks of fruit, so I took a temperature reading for sanity - 46F. Shouldn't be getting esters at that temp.

So... lagers piss me off.

Hang in there!

You're right. I've just had such a high rate of total/partial failure with lagers I'm a tad jumpy. I'll check gravity in a couple days, and I'll withhold judgment on flavor until the yeast have dropped out.

I'm with you bernerbrau, lagers piss me off as well lol. I will keep at them though, one day I'll get one to turn out awesome.

TheMan said:

I'm with you bernerbrau, lagers piss me off as well lol. I will keep at them though, one day I'll get one to turn out awesome.

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Pitch enough yeast and ferment at the right temperature and it's all good!

So, just to be clear, at high krausen with lots of suspended yeast, fruit flavors are normal? Even in a light lager? Do the esters just "stick with" the yeast, or what?

You're using W-34/70 so I'm surprised you're getting fruit. It's never given me any fruitiness whatsoever, from 44 degrees to low 50s. I wonder if you're picking up something from your hops.

I'm fermenting a batch of Bohemian pilsner right now with S-23 and it's fruity as hell. Also seems to be struggling to work at 45 degrees--it's moving, but it's darned slow (OG 1.052 ten days ago; now at 1.028ish). I should note the only other time I used S-23 was in a similar beer fermented in the mid-50s, and the finished beer is not fruity at all (so it might be a great lager yeast for those who can't get their ferm temps below about 55).

Meanwhile my doppelbock using 34/70 slurry is going gangbusters right next to it. I almost can't ferment cold enough to slow down that yeast! If I can get the pils down to 1.020 I'll warm it up for d-rest which should finish it off. Actually I think I would be safe taking it out now but I want to see how far it will go by itself so I can learn a bit more about S-23.

osagedr said:

You're using W-34/70 so I'm surprised you're getting fruit. It's never given me any fruitiness whatsoever, from 44 degrees to low 50s. I wonder if you're picking up something from your hops.

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Can Saaz come through as "fruity"? The aroma was overwhelming from the hydro sample. Normally I drink the contents of the test jar but this was pretty nasty.

The only other thing I can put my finger on is maybe I didn't wait long enough for the wort to come down to pitching temp.

Could be. The yeast is definitely not fruity at normal ferm temps.

Well, sonofabitch. I guess I'll let it ferment out and see how it is after the yeast drops.

My patience for lagers is wearing thin. Maybe I'll just admit I can't make a damn lager and go back to ales.

Nah, if you're set up to lager you just need to keep a few tips and tricks in mind. Chill it down to pitching temps (mid to high 40s), pitch two packs of W-34/70 rehydrated, then sit back and watch the magic.

Well, the analog temp controller is set to 45 and the probe is taped to the outside of the BB. I couldn't get a good reading with any of my digital thermometers, and the glass thermometer came back with 46, and even though the tolerance is a woeful 5 degrees on that thing, at worst we're talking 51.

Unless I misread "50" as "45" (50 is not marked), in which case it was actually 51, and it could actually be as high as 56.

I think my next investment is going to be a thermapen, a digital temp controller and a thermowell for the BB, so I have better control over wort temperature and I can actually verify it.

I just pitched two straight lagers on the same yeast cake (actually a mix of Bohemian Pils and Bohemian Lager from Wyeast.) The first one that fermented smelled like pils the whole way. The next batch gave off serious rhino farts. My guess is that your beers will be fine after lagering, lagers are just a bit odd during/following ferment.

Just transferred this to secondary yesterday. Still very hazy and a distinct fruity smell. Tasted the hydro sample... no perceptible taste of fruit whatsoever. A slight tartness, but not one I would describe as "infected". Pretty tasty for a green lager that's still got yeast in suspension.

There may be hope for this brew yet. My only concern is I won't be able to lager it for a while. I just put an APA in the freezer at 62F, and after that I'm hoping to get a bock in that spot just so I don't have an empty space in my freezer for 8 weeks.