Getting high attenuation from a lager yeast

Hello All,

I'm kicking around the idea of trying to brew up a lighter lager that can be a session beer I always have around. What I'm shooting for probably most resembles Sam Adams Light if I had to reference a commercial example. I plan on going with a basic 2 row base, toasting it myself to darken it to about 10L, doing a decoction with a step up to a mash at around 148-150, following by a normal fermentation schedule of about 2 months between the primary and lagering phases. I'm brand new to All-Grain, and part of the reason I want to take a stab at something like this is because it incorporates a few things process-wise that I've never done, but want to learn, not to mention I'm in search of a session beer that I will want to brew repeatedly.

The big challenge is getting the FG where I want. Based on the numbers I've run, my OG will need to be around 1.037-1.039 with an FG around 1.005-1.007, to hit my goal of an ABV of around 4.2% while maintaining a light body. To get that low I know I will need to get pretty good attenuation from my yeast. I've read up on a few strains from Wyeast and WL that state they can get to the high 70's or 80% attenuation, however to hit the OG and FG I noted above, that might need to push a few % points higher.

Does anyone have experience getting a lager down that low? Beyond a low mash temp, oxygenating well, pitching a healthy active starter, and using a high attenuating lager yeast, what else can I do to try hit my target? Considering my lack of experience in this arena, any tips or suggestions would be appreciated.

You hit everything on the head to get the attenuation that low. The only other thing you could do is add some simple sugars, but I'd advise against that in a lager. Just mash low, aerate it good, and you'll be fine.

So as a follow up to my initial post, I've done a bit more reading the last few months to better understand both decoction mashing (which Sam Adams uses in their Light per info on the website), and the use of Amyloglucosidase, which essentially was used to create the Light American Lager style as we know it today IIRC.

The more I look at the description of how Boston Beer Co. brews SA Light, the more I have to believe it's more than just mashing low and pitching a lot of healthy yeast. Per their website, SG is 9.2 Plato (1.037), and at 4.3% that means it finishes at 1.004, for 89% attenuation. That in itself is really high. They also state they use Crystal 60, which per a Mr. Wizard column in the Jul/Aug 2003 issue of BYO contains compounds that a debranching enzyme won't break down into fermentable sugars, but will contribute to the beer's FG. Lastly, they state they use a decoction mash, which I suppose, it done appropriately, could really enhance fermentability if the right rests were used.

I guess what I'm getting at is, does anyone think it's possible to hit an attenutation around 90%, with a grist that includes Crystal malt, without the use of a debranching enzyme? Granted, I'm no expert by any means, but this seems unlikely considering what is known about this beer.

Wouldn't the old Beano discussion come into play here. Check byo's online page and there should be an old Mr. Wizard experiment with Beano. Essentially, the enzime debranches some previously untouchable sugars and starches and lowers the final gravity dramatically -- which also lowers carbohydrates while raising the alcohol.

Brewday365 said:

Wouldn't the old Beano discussion come into play here. Check byo's online page and there should be an old Mr. Wizard experiment with Beano. Essentially, the enzime debranches some previously untouchable sugars and starches and lowers the final gravity dramatically -- which also lowers carbohydrates while raising the alcohol.

Click to expand...

That's the article I'm referring to, his Beano experiment. I included the link this time:

http://byo.com/stories/wizard/article/section/121-mr-wizard/181-beano-brau-a-hefewizens-mr-wizard

What I'm trying to figure out is if you need it to hit the low FG and high attenuation in a light lager that doesn't use any adjuncts, or if throwing every trick in the book to create a fermentable wort is enough. Furthermore, if it is used, would the inclusion of Crystal malt keep it from drying out down to like a 1.000 FG. I'm tempted to experiment with this myself using Beano to see where I get. I have no desire whatsoever to try to brew a BMC'ish light beer, but if I can get something along the profile of an SA Light, I think it may be a nice session beer to have around.

I suppose that it all depends on why. I tend to get fixated on something purely out of curiosity more than actual design. So I have a list of questions:
1) Are you worried about mouth feel or perceived sweetness?
2) Do you like or dislike the taste Caramel 60?
3) Do you like or dislike the color of Caramel 60?
4) Are you interested in how low an attenuation that one could possibly get?

From the original post, it sounds like you are fixated on the last few points. I would try a few things -- perhaps split batches. First, the sound practices that you mentioned the mashing temps, pitch rates, oxygen, etc... The Beano will probably get you the last few points, but so might the Caramel 60 substitute (put it into a promash calculator or Hopville, etc... and see). Finally, and this is my hair-brained experiment idea, try adding a fresh slurry of wine or champagne yeast after beer yeast have kicked out. Wine, sake, and cider yeasts are typically greater than 80% attenuation. If just chewing up a few gravity points, they most likely won't throw off too many flavors.

Let me know how this goes.

Brewday365 said:

I suppose that it all depends on why. I tend to get fixated on something purely out of curiosity more than actual design. So I have a list of questions:
1) Are you worried about mouth feel or perceived sweetness?
2) Do you like or dislike the taste Caramel 60?
3) Do you like or dislike the color of Caramel 60?
4) Are you interested in how low an attenuation that one could possibly get?

From the original post, it sounds like you are fixated on the last few points. I would try a few things -- perhaps split batches. First, the sound practices that you mentioned the mashing temps, pitch rates, oxygen, etc... The Beano will probably get you the last few points, but so might the Caramel 60 substitute (put it into a promash calculator or Hopville, etc... and see). Finally, and this is my hair-brained experiment idea, try adding a fresh slurry of wine or champagne yeast after beer yeast have kicked out. Wine, sake, and cider yeasts are typically greater than 80% attenuation. If just chewing up a few gravity points, they most likely won't throw off too many flavors.

Let me know how this goes.

Click to expand...

To answer your questions:
1) No. The experiment to try to get down to 1.004ish should dry the beer out but hopefully retain some of the roasty/caramel flavor from the malt.
2 & 3) In this beer, I think it will work well for reaching the desired color and flavor profile.
4) To an extent. I'd like to see how much you can dry out a light lager and still retain some character, something BMC Light don't do but IMO, SA Light does.

This qualifies somewhere along the lines of a "I wonder if I can pull it off" type of experiment. I think making a lower cal beer that still retains a good amount of flavor is an interesting idea to take a shot at, more because it's a challenge then the fact that it will turn out a really good beer (though that's obviously the goal). It's probably fair to say I'm trying to clone SA Light, which is why I'm trying to stick to what I know about the beer as far as ingredients and processes goes. Ultimately, if it turns out good, I could care less if there are differences.

I don't know when I will get to this as I have 4 different German lagers I want to brew first, but if I do, I'll probably shoot for something like this:

-90% Domestic 2-Row, toasted in the oven, wet, at 350 for about 20-30 mins
-10% Crystal 60L
-Shoot for an OG of around 1.037
-A Hochkurz style Decoction mash with a long maltose rest around 140-142, but instead of moving to a dextrine rest at 158, I'll decoct and rest again at around 150 before the mashout decoction.
-Add some Beano once fermentation slows down, then let it finish out and see what happens.
-0.5oz Spalt hops at 60 & 10.
-I'm thinking WLP840 would probably be a good choice for yeast, however I plan on using WLP833 for the German Lagers I will brew first, so I might end up using that assuming I decide to wash it and it's still viable enough.

In theory, though my logic could be way off on this one, Beano should convert pretty much all of the 2-Row sugars, leaving some of the Maillard Reaction Products (as described by Mr. Wizard) in the Crystal 60 behind, so the beer doesn't dry out all the way to 1.000. If this idea flops, it won't bother me much. This is really brewing just for the fun of brewing, if it yields a really nice beer, that's just icing on the cake. It could also be a complete disaster, which I can handle if I have fun doing it.

Take a look at this recipe / discussion:
https://www.homebrewtalk.com/f62/miller-lite-really-triple-hopped-123937/

It centers around a low OG brew and uses amylase after primary fermentation is done to help it finish super low. I hesitate to refer to it as a session beer as the amylase might kick it up a percent or so.

The one caveat is that it's not using any crystal, so I'm not sure how that would affect the final gravity.

Fwiw, I've read that beano won't quit. Given that you're shooting for as much attenuation as possible I suspect that won't be a problem, but I understand that it's much harder to use when you're trying to lower your gravity by just a few points.

airving said:

Take a look at this recipe / discussion:
https://www.homebrewtalk.com/f62/miller-lite-really-triple-hopped-123937/

It centers around a low OG brew and uses amylase after primary fermentation is done to help it finish super low. I hesitate to refer to it as a session beer as the amylase might kick it up a percent or so.

The one caveat is that it's not using any crystal, so I'm not sure how that would affect the final gravity.

Fwiw, I've read that beano won't quit. Given that you're shooting for as much attenuation as possible I suspect that won't be a problem, but I understand that it's much harder to use when you're trying to lower your gravity by just a few points.

Click to expand...

Ironically, when I was first learning about enzyme additions to dry out a beer I looked at this recipe. Maybe the ultimate thing that is being tested here is whether you can add Crystal malt to keep the beer from drying out all the way, which is really the one of the questions that would probably be answered. Now that I see HB stores sell this, using Amylase enzyme is probably preferred to Beano, since it's actually made for brewing.

I think the goal Boston Brewery had when making SA Light was to see if you could retain some flavor and character in a light beer that is dried out to a low FG. BMC Light beers lose pretty much all flavor when they dry out to close to 1.000. Clearly, adding enzyme works to dry out a beer and achieve near 100% attenuation (as the recipe you linked shows). The question I'd like to answer is can you do the same thing, using 100% malt with no adjuncts and the right process, that still leaves the beer with some flavor, something BMC Light pretty much eliminates with the use of rice and enzymes to dry the beer out. In this case, the combination of roasted base malt and Crystal 60 should do that... in theory, whereas BMC Light uses 2/6-Row and Rice, which leaves no flavor behind.

I'm interested in the results of any of these experiments. Please keep us posted.

as far as I understand the hochkurz double decoction, it's the maltose rest that will determine fermentability of the wort, not the dextrinization rest. i'm not sure if using a lower dextrinization rest temp will increase the fermentability and could cause foam instability etc. or perhaps result in a lower conversion rate/efficiency. i think if you do a low temp and long maltose rest ~140-142 as you mention you should be able to keep the suggested dextrinization rest temp ~ 158 and still get low FG.

also, a double decoction is a lot of time consuming work (added an extra 90 or so to my brew day) - i'd be hesitant to add beano as an experiment in the entire batch after all the time and effort that you will put into a double decoction as well as lagering etc. but i thin it could be cool to do a side by side experiment if possible, but obviously it's your personal choice.

also, not sure the impact of roasting your entire base malt, as i've never done it and usually only see people oven roast a portion, but perhaps you've already done the research on that one.

def curious to hear about your results - good luck

terrapinj said:

as far as I understand the hochkurz double decoction, it's the maltose rest that will determine fermentability of the wort, not the dextrinization rest. i'm not sure if using a lower dextrinization rest temp will increase the fermentability and could cause foam instability etc. or perhaps result in a lower conversion rate/efficiency. i think if you do a low temp and long maltose rest ~140-142 as you mention you should be able to keep the suggested dextrinization rest temp ~ 158 and still get low FG.

also, a double decoction is a lot of time consuming work (added an extra 90 or so to my brew day) - i'd be hesitant to add beano as an experiment in the entire batch after all the time and effort that you will put into a double decoction as well as lagering etc. but i thin it could be cool to do a side by side experiment if possible, but obviously it's your personal choice.

also, not sure the impact of roasting your entire base malt, as i've never done it and usually only see people oven roast a portion, but perhaps you've already done the research on that one.

def curious to hear about your results - good luck

Click to expand...

Trust me, the thought of not only home roasting my base malt, doing a LONG decoction day (which would be even longer than normal with a longer maltose rest), getting a big enough starter, waiting a few weeks for a lager primary fermentation to take place, then wait another 6 weeks for the lagering period has me wondering if it's really worth it for a light beer... When I read that sentence back, I sound like I've completely lost my common sense. For an oak aged RIS or an Imperial IPA maybe, but a light beer, come on! For that reason, I probably won't get to this any time soon, there are too many other beers I'd like to brew (and drink) before then. I do think this is an intriguing experiment to try though, and I think I will someday when I have the free time. I do agree, this is the perfect candidate for a split batch, though my 9 gallon kettle isn't big enough to brew 10 gallons of wort without resorting to a partial boil.

As far as the science behind the 140 & 150 rests in the Hochkurz method, I will have to do more reading, because you may be right, moving the second saccrification rest down from 158 to 150 may not do anything except waste time, and might even be counter-productive. I guess that's the fun of brewing experiments though (if you have the time), you form a theory and test it out

my hochkurz double decocted vienna lager was def well worth it, but a 7hour brewday and eyeing the bucket/keg for several weeks made me question it at the time

perhaps you could just set aside some of your 5g batch when you go to lager and add a little beano/amalyse to that when you get around to brewing it. that way you have a good side by side and still have the majority of your beer safe

one of my favorite things about this hobby is that there are many "right ways" to accomplish our brewing goals

terrapinj said:

my hochkurz double decocted vienna lager was def well worth it, but a 7hour brewday and eyeing the bucket/keg for several weeks made me question it at the time

perhaps you could just set aside some of your 5g batch when you go to lager and add a little beano/amalyse to that when you get around to brewing it. that way you have a good side by side and still have the majority of your beer safe

one of my favorite things about this hobby is that there are many "right ways" to accomplish our brewing goals

Click to expand...

I'm doing a Hochkurz double decocted Marzen in a couple weeks, we'll see how I feel about it after that.

HopRodGR said:

Trust me, the thought of not only home roasting my base malt...

Click to expand...

FYI, when toasting your own malt you want to do it at least two weeks in advance. From John Palmer:

The malt should be stored in a paper bag for 2 weeks prior to use. This will allow time for the harsher aromatics to escape. Commercial toasted malts are often aged for 6 weeks before sale. This aging is more important for the highly toasted malts, toasted for more than a half hour (dry) or 1 hour (wet).

I recently kegged up a light beer. I used alpha galactosidase to break up unfermentable carbohydrates. Partly as a joke, I triple hopped the beer. Actually I "three cubed" it - three hops at each of three times (~14 IBUs total). Seriously though, my reason to "three cube" hop it was that I know the big guys use hop blends to get a consistent product. If in any given year one of the hops was out of whack due to weather etc, it wouldn't be so noticeble. Sort of the opposite of using a single hop. I wanted to use a blend of hops so none stuck out - in true BMC fashion. This beer was just 4 lbs of pils malt. 1.5 lbs flaked corn (calc for 90% effeciency). The beer finished up at 1.004. the sample I tasted at kegging was very smooth and BMC lite like. The biterness was not apparent on first tasting, just like the big boys. However after swallowing there was a nice bitter after taste that the BMC lites don't have.

Here is another enlightening article from Mr. Wizard at BYO on creating a fermentable wort.

http://byo.com/stories/wizard/artic...-mash-temperatures-create-a-sweet-or-dry-beer

Well into the article, he states that Bud Light doesn't use enzymes like many other light beers. They use a step mash schedule that starts around 140, and increases to 158, to hit all ranges of both Beta and Alpha-amylase. IIRC Bud Light is about 4.2%, 110 cals and about 6-7 carbs per 12oz. If you punch in the right numbers, this means they'd start around 1.035 and finish around 1.002. With the right grist this seems perfectly conceivable.

I'm pretty intrigued by this all now, and think an experiment with two separate mashes would be interesting. Mash #1 would use a slightly more toasted base malt with less crystal, using a decoction that rests a long time (maybe 2 hours?) at around 140-142, then is slowly stepped up multiple times via the first decoction to a final rest at 158 for another hour, before decocting to mashout. This would not use any enzyme. Mash #2 would use a lighter toast, more crystal, employ the same mash schedule but use some denaturing enzyme toward the end of fermentation.

I'm more convinced than I was before than you can probably do this without enzyme, using the right grain bill, a long step mash geared for fermentability, plus an appropriate yeast pitching rate. Plus, it would surprise me if my commercial example, SA Light, employed enzymes in the brewing process. That just doesn't seem like something Boston Brewery would do.