Diastatic Yeast - How to Minimize Attenuation?

[Protos]

Gentlemen, I'm thinking over a task with mutually exclusive conditions: to make a sessionable beer with a Diastatic yeast without overdrying it.

I plan to brew a Belgian-Pale-Ale-Style beer (max. 5% ABV) with Mangrove Jack's M41 Belgian Ale diastatic yeast, the average attenuation of which in my previous brews has been as high as 96%. What I need is, essentially, to lower somehow its attenuation down to 80%, to get the desired 5% beer from a 1.048 OG wort (I don't want to go any lower, to avoid getting a watery beer).

The standard way to lower attenuation is upping the Dextrine content of the wort, which is achieved by mashing higher or adding more Crystal. This approach however doesn't work with Diastatic yeasts which perfectly ferment Dextrins.
Adding Rye or Oats may boost the mouthfeel but has anything to do with the attenuation. My previous Crystal-rich or Rye Saisons all have been highly attenuated.

I've run out of ideas what else can I do to inhibit the attenuation. Any ideas would be welcome.

 

[lumpher]

Only way I can think of is to monitor it and kill off the yeast with k-meta and k-sorbate when it reaches where you want it.

 

[Protos]

I've run out of ideas

Not really, it appears.
After me drinking a bottle of a very nice homebrew (a Bohemian Budweiser clone, whch came out just perfect this year), the brain finally delivered the answer I was seeking for: LACTOSE
Thank you all for your suggestions

Now: how much of it?
Never used it in pale beers, and no brewware seem to give an adequate estimation of its impact on the attenuaton...

 

[Miraculix]

Not really, it appears.
After me drinking a bottle of a very nice homebrew (a Bohemian Budweiser clone, whch came out just perfect this year), the brain finally delivered the answer I was seeking for: LACTOSE
Thank you all for your suggestions

Now: how much of it?
Never used it in pale beers, and no brewware seem to give an adequate estimation of its impact on the attenuaton...

Or use a yeast that produces loads of glycerine. That makes the beer taste like it was attenuated within a "normal" range. Belle saison would be an example of such a yeast.

 

[Protos]

Yep, M41 is also a high Glycerol producer, no less than M29.
Upping mouthfeel is an easy task, I need something more challenging: to keep alcohol at bay without going too low in OG. Glycerol of Glucans won't help with that. Lactose might, I hope.

 

[DBhomebrew]

Are you using a diastatic yeast when you don't want diastatic attenuation just for the challenge? Why gung-ho on the M41?

 

[Protos]

Someday a time comes when your usual fetishes just fail to turn you on anymore...

I just love the flavour of M41, it's like no other. Every summer I brew a beer with it.
But now, having a huge surplus of Strong Golden Ales from the previous years, I just can't brew one more.
So, a task with mutually exclusive conditions was put.

 

[Protos]

Yay!
Found an article in BYO on a brewery that makes a Saison with 9% of Lactose and a Saison yeast and gets 80% attenuation.
Exactly what I need.

 

[mac_1103]

One pound of lactose adds 7 unfermentable gravity points to 5.5 gallons of wort.

 

[mac_1103]

A pound of maltodextrine also adds 7 gravity points to 5.5 gallons of wort. Non-fermentability is less certain however.

 

[Protos]

Great.
Question's solved

 

[SanPancho]

dont do lactose. that sounds gross. malto wont work, the m41 will just keep eating.

so my understanding and experience is that diastatic activity isnt necessarily a part of primary fermentation. some yeasts will go crazy and all out from start to finish, but alot have a bit of lag between when primary "finishes" and the yeast start turning on the st1 stuff and chomping dextrines. i'm not familiar with that yeast so i have no idea. but T58 sits for a while before it starts going again. and so does sach trois. ymmv.

so what we have done is monitor it pretty closely towards the end of primary, and when we feel like the beer is in a good place, we'll pitch some dextrose and some f2 yeast to carbonate naturally. (f2 is same as cbc ) its got the "killer" gene that alot of wine yeasts have, so it'll likely stop the m41 from fermenting any further. and it only eats simple sugars, so it wont affect your FG.

other than accounting for the priming sugar you just use your regular recipe. probably would be worth doing a quick co-pitch forced ferment test of f2 and m41. monitoring the gravity should tell you if the m41 is killer-resistant and will not be stopped.

 

[Protos]

I don't have access to F2 or CBC, unfortunately...
M41 doesn't have a lag time or staggered bouts of activity, it munches through the wort quick and steady, gradually slowing down by the end.

Why adding Lactose sounds gross?

As far as I remember it didn't produce any off-flavours in the dark beers I've used it in.
Haven't tried it in pale beers, though, so I don't really know what to expect from it. Hopefully, Lactose is no worse than Metabisulphite (which I hated in my wines for its lingering sulphuric whiff) and Pasteurisation, which strips beer of much of its flavours.

 

[DBhomebrew]

Why adding Lactose sounds gross?

Merely speaking for myself, I can't stand the mouthfeel of lactose. Maybe it's a dosage thing, maybe it's a whatever else thing, but after two or three tries I now skip right past the lactose offerings.

 

[DBhomebrew]

As usual, ymmv.

 

[AlexKay]

I've been experimenting with adding inulin as an unfermentable starch, to add body but not sweetness or calories. My first try with this gave very positive results.

 

[dmtaylor]

If you want to go with 100% malt, I would recommend mashing hot at about 160 F for a very short time, just 20 minutes should suffice. Expect slightly reduced efficiency, to go along with your reduced attenuation. Mash TIME is probably even more important than the temperature. Then get it up to the boil ASAP, don't dawdle.

Lactose, of course, is perhaps an even simpler alternative -- cheers to that as well.

 

[SanPancho]

I don't have access to F2 or CBC, unfortunately...
M41 doesn't have a lag time or staggered bouts of activity, it munches through the wort quick and steady, gradually slowing down by the end.

Why adding Lactose sounds gross?

As far as I remember it didn't produce any off-flavours in the dark beers I've used it in.
Haven't tried it in pale beers, though, so I don't really know what to expect from it. Hopefully, Lactose is no worse than Metabisulphite (which I hated in my wines for its lingering sulphuric whiff) and Pasteurisation, which strips beer of much of its flavours.

Well in a really dark beer you may not notice it but in anything pale or clear it’s very noticeable. (To a lot of folks) Even though Belgians are typically dry the esters often have sweet notes. So to me it’s doubling up the sweet notes. But if you don’t “taste” the lactose then you wouldn’t have a problem with it.

CBC is lallemand. F2 is fermentis. Both should be available widely. If not, do you have access to wine yeasts? You could probably use k1116 champagne yeast to do the same thing. (Pretty sure it’s also “killer”)

 

[Protos]

I would recommend mashing hot at about 160 F for a very short time, ju

But what do I get from that? More Dextrine, which the Diastatic yeast will ferment out anyway? Or extra low OG, which I'd like to avoid?

 

[Protos]

So to me it’s doubling up the sweet notes

Ah, I see now. If no funk or off-taste is involved, high sweetness alone doesn't look like a problem to me. I like beers which most other find "cloying".
My planned Belgian Pale isn't much pale and clear with Vienna malt as the base and 15% of Biscuit, hopefully it masks a bit any funny twangs if there might be any.

I see I need to explore the wine killer yeast thing. I don't know if Champagne yeast is sold here, I make wines so rarely (actually, once per year, just to not throw away the grapes that grow in my yard) and I'm such a noob in the wine department, I never buy yeast, I make my once-in-a-year Porto with a wild fermentation.

 

[mac_1103]

T58 sits for a while before it starts going again

T58 is not diastatic.

so what we have done is monitor it pretty closely towards the end of primary, and when we feel like the beer is in a good place, we'll pitch some dextrose and some f2 yeast to carbonate naturally. (f2 is same as cbc ) its got the "killer" gene that alot of wine yeasts have, so it'll likely stop the m41 from fermenting any further.

I was wondering if a killer yeast would kill fast enough for this to work.

 

[dmtaylor]

But what do I get from that? More Dextrine, which the Diastatic yeast will ferment out anyway? Or extra low OG, which I'd like to avoid?

There are all different lengths of dextrins. The more complex dextrins, the yeast may or may not be able to eat. You'd probably need to experiment over several batches to get it right.

Efficiency doesn't suffer as much as you might think, in my experience. Knock 5-10% off. Not a big deal if you average >80% efficiency as I do.

Or just use lactose.

 

[SanPancho]

T58 is not diastatic.

I was wondering if a killer yeast would kill fast enough for this to work.

no, its not. i mixed up the numbers, always happens with the number-name yeasts. hops too.

that recipe uses wb06 in the mix. which is diastatic.

and our experience is that by rehydrating the f2/cbc before pitching with the priming sugar, it takes off fairly quickly and we dont really see any further decrease in FG. one point is the most we ever saw it drop. but again, the wb06 seemed to "stall" at the end of primary and sort of hang out for a while (week or two) before it kicked up again. if OP is saying that the m41 yeast doesnt slow at all and just powers all the way through to 96% AA then that would be alot harder to get right in terms of timing.

 

[Jeroen79]

I would just use a non diastatic yeast, wanting low attenuation and a diastatic yeast will just make it unneedingly difficult.

 

[Protos]

a diastatic yeast will just make it unneedingly difficult.

Even with non-fermentable Lactose? But why?

 

[Drewch]

Have you thought about using Lallemand Farmhouse instead? I haven't tried it yet, but they bred (i.e., non-GMO if you're worried about that) a yeast for Saison-y flavors, but it's STA negative.

https://www.lallemandbrewing.com/en/united-states/product-details/lalbrew-farmhouse/

 

[Jeroen79]

Even with non-fermentable Lactose? But why?

I call having to add lactose aleady make it more difficult, is there any reason you absolutly wan't to use that yeast?, there must me other strains that have the desired flavors?

 

[mac_1103]

I really don't get the almost visceral anti-lactose response. Unless you're lactose intolerant of course, in which case I suppose the response literally is visceral. I've only used it in things like milk stouts (where the name suggests that it belongs) and I'm not sure that I would try to use it this way. But dumping in a pound of powder at flameout is not hard. And you know what? It's his beer. If he'd rather experiment with non-fermentable sugars than experiment with different yeasts then who am I to tell him he's wrong?

 

[Jeroen79]

Its not about being anti-lactose, just curious why he want's to do it the hard way, but ofc if he has fun experimenting with those thingt then he schould definitely try it that way!

 

[mac_1103]

Its not about being anti-lactose

That part was directed to you specifically.

just curious why he want's to do it the hard way

Maybe because it's not hard?

 

[Protos]

experimenting

That's exactly what I'm doing.
With M41, I've been brewing only two styles for years: Belgian Golden Strong and Belgian Dark Strong. I already have a surplus of both in my cellar.
I love the yeast and now I want to try it in a completely different style.

 

[Protos]

Have you thought about using Lallemand Farmhouse instead?

I have, just not for this experiment. I have a sachet of this yeast for a year already, couldn't decide what to brew with it. Then I saw a suggestion on this forum to try it in a Bière de Garde, which I will do when the Lagering season returns.