Belgian Wit: % Flaked Wheat in the Mash

[Killshakes]

I'm preparing to brew my first Belgian-style Wit beer, and the recipe I've put together contains the following grain bill:

Pilsner malt - 47.5%
Flaked wheat - 47.5%
Flaked oats - 5%

The grains and ratios are in line with other Wit recipes I've seen, but many of the resources I've encountered (various articles, BeerSmith 2, etc.) claim that 40% is the maximum amount of flaked wheat that can be used.

What do you think? Am I bound to have a conversion problem with this grain bill? What adjustments, if any, would you recommend?

 

[cswis86]

I've used 50/50 flaked wheat and pilsner malt in my witbier with success. I did a 15 minute protein rest followed by a 60 min sacch rest. The beer went from 1.052 to 1.010 so conversion wasn't a problem. I think you'll be fine.

 

[Killshakes]

I've used 50/50 flaked wheat and pilsner malt in my witbier with success. I did a 15 minute protein rest followed by a 60 min sacch rest. The beer went from 1.052 to 1.010 so conversion wasn't a problem. I think you'll be fine.

That helps put my mind at ease a bit. I wonder why so many sources claim that ~40% is the maximum?

By the way: What yeast did you use? I'm going to try WLP 410 for this one.

 

[IslandLizard]

Do they give a reason why 40% flaked wheat would be the "limit?"

Modern day highly modified Pilsner malt has a Diastatic Power (DP) of around 120-160°L (°Lintner). Thus it's able to convert another 2x its weight of non-diastatic adjuncts, or even more.

That said, I typically use 40% flaked wheat in a Wit plus another 10-20% wheat malt, 5-10% flaked oats, sometimes a little Crystal 10L or 20L. The balance is Pilsner or 2-row pale.

 

[Killshakes]

Do they give a reason why 40% flaked wheat would be the "limit?"

BeerSmith 2 didn't list a reason. The articles I read seemed to say that flaked wheat lacked any diastatic power of its own and that using even 40% would strain / exceed the ability of the typical pilsner malt (I bought "Bohemian"--presumably Czech--pilsner malt) to convert the starches in the mash, and that the mash times would have to be much longer than the typical 60 minutes.

 

[cswis86]

That helps put my mind at ease a bit. I wonder why so many sources claim that ~40% is the maximum?

By the way: What yeast did you use? I'm going to try WLP 410 for this one.

Don't know where 40% came from. This is from BeerSmith which mirrors your recipe: "Belgian Wit is made from a base of around 50% pale malt, and 50% unmalted wheat. Often 5-10% rolled or flaked oats are added to enhance body and flavor."

I used Wyeast 3942. Never used WLP410 but it'll do the job.

 

[IslandLizard]

BeerSmith 2 didn't list a reason. The articles I read seemed to say that flaked wheat lacked any diastatic power of its own and that using even 40% would strain / exceed the ability of the typical pilsner malt (I bought "Bohemian"--presumably Czech--pilsner malt) to convert the starches in the mash, and that the mash times would have to be much longer than the typical 60 minutes.

Bohemian Pilsner malts may not be as "highly modified." Is there a DP listed or a malt analysis number/code that can be looked up?

I know the Bohemian Floor Malt variety is definitely undermodified.

If the average grist DP is borderline (~35°L), you can always replace some flaked wheat with inherently high diastatic wheat malt (~160-180°L). That will boost the average DP of the whole grist, while not changing the flavor profile all that much. Or mash for 90 minutes, and check for conversion completion.

 

[Killshakes]

Bohemian Pilsner malts may not be as "highly modified." Is there a DP listed or a malt analysis number/code that can be looked up?

I know the Bohemian Floor Malt variety is definitely undermodified.

if the average grist DP is borderline (~35°L), you can always replace some flaked wheat with inherently high diastatic wheat malt (~160-180°L). That will boost the average DP of the whole grist, while not changing the flavor profile all that much. Or mash for 90 minutes, and check for conversion completion.

It wasn't the floor malted type. The DP listing says that it was >250 WK, which I think converts to "greater than" 76 L (the same as a German pilsner malt that was also available). 76 is just over what I'd need (~70 L, right?) to convert everything in the grain bill, but it's close. Maybe I should change the %'s to something like 50% pilsner / 45% flaked wheat / 5% oats to be on the safe side.

 

[IslandLizard]

BTW, you are going to step mash this, giving it a protein/beta-glucanase rest at 122F for 15-20 minutes? When I do that I usually don't need rice hulls, and while the lauter is not very fast, it doesn't get stuck either.

 

[IslandLizard]

The DP listing says that it was >250 WK, which I think converts to "greater than" 76 L (the same as a German pilsner malt that was also available).

76°L is fairly low! With 50% adjunct, you're only a little above 35°L. Mash longer or substitute some flaked wheat with wheat malt.

 

[Killshakes]

BTW, you are going to step mash this, giving it a protein/beta-glucanase rest at 122F for 15-20 minutes? When I do that I usually don't need rice hulls, and while the lauter is not very fast, it doesn't get stuck either.

Yep. 20 minutes at 122.

I'm using a modified BIAB method though, so lautering isn't an issue. I plan to use roughly half of the total water volume for the protein rest (122), and then infuse most of the remaining water to reach the target sacch temp. (~150). After that I'll infuse the rest of the water and add heat to reach the mash out temp. (168), pull the bag, drain and prepare to boil.

 

[IslandLizard]

Yep. 20 minutes at 122.

I'm using a modified BIAB method though, so lautering isn't an issue. I plan to use roughly half of the total water volume for the protein rest (122), and then infuse most of the remaining water to reach the target sacch temp. (~150). After that I'll infuse the rest of the water and add heat to reach the mash out temp. (168), pull the bag, drain and prepare to boil.

Ah, good!
You can always interrogate that bag when you come up short on volume.

 

[Killshakes]

Ah, good!
You can always interrogate that bag when you come up short on volume.

Why would I come up short on volume?