Low OG Witbier

[Craftbrewhaha]

So I spent the afternoon brewing up my first Witbier. This is only the second time I've brewed with Flaked Wheat and Flaked Oats. I brewed a beer yesterday with 4.5 lbs of Flaked Wheat and hit my gravity dead on. I brewed a different beer after with 1.5lbs of Flaked Oats and missed the mark by about -.002. After checking my OG for my Witbier I brewed today (I will post grain bill below) I was under by .012 points. I'm not too upset as it's all a learning experience for me and in the end it will still be beer. I was just looking for an outside analysis of my brew day and maybe tell me where I'm going wrong with these Flaked Oats (it seems anyway).

Witbier Grain Bill - 5.5 gallon batch

5lbs Pilsen Malt
4.5lbs Flaked Wheat
1.25lbs Flaked Oat
.25lbs Munich Malt

The flaked grain were unmilled

10.40 qts of water at 122 degrees for 30m
9.240 qts of water at 154 degrees for 30m
I did not Mash Out which I'm investigating as a potential problem
Sparged with 1.3 gal of water at 168 degrees over an hour
90 minute boil. Started with 6.22 gallons of wort ended with 5.5.

I did have a stuck runoff in the brew using Flaked Oats yesterday. I used rice hulls in the brew today and eventually ended up with less flow than normal. Eventually it got to the point where it was so slow I gently blew air into mash tun through the drain hose and cleared things up. But the runoff still took about 90 minutes instead of 60m.

I think that's all the relative information about my brewday that would impact my grain and gravity. Let me know if you see where I went wrong or could fix something. It's a constant exciting learning process so I love the input. Thanks guys!

[anday6]

Two concerns:
1. I'm not sure that the pilsner has enough diastatic power to convert all of that flaked grain. You would want to sub out for some malted wheat to lighten the load or do some kind of cereal mash. (I'm 99% sure flaked wheat and oats still need to be converted even though they are already gelatenized)
2. Did you do anything to adjust your mash pH for mash this light? Mash pH can have a big effect on conversion also.

[Craftbrewhaha]

1. I'm not sure that the pilsner has enough diastatic power to convert all of that flaked grain.

I'm not sure about this either, but I can say that I based this recipe pretty closely to Jamil's Witbier recipe he put in BYO. I've been taking his word as gospel recently for recipes and I've been succeeding, so I trusted this recipe fully. But I will definitely look into that.

2. Did you do anything to adjust your mash pH for mash this light? Mash pH can have a big effect on conversion also.

Water chemistry and mash pH are quickly rising to the top of my list of brewing techniques to work on. What would you should suggest for adjustments on a beer like a Witbier? Or if you have any sources you would recommend? Currently all I do in these respects is use a carbon filter for my water and use a pH strip to check my mash pH (when I remember), then I look at it and say, "Oh, cool." and move on.

Thanks for the response!

[spiderwrangler]

I'm 99% sure flaked wheat and oats still need to be converted even though they are already gelatenized.

Add 1% to that. Gelatinization only makes the starches accessible, you still need to convert with enzymes to get any fermentables out of flaked grains.

[brewinhard]

Looks like you probably have enough pilsner malt in there to convert your flaked grains. With that being said, I brewed two wits in a row using a no sparge method. The first wit, ended up at 1.042 (instead of 1.050 which gave me a 55% eff.). The second wit, I lowered my efficiency on my software to 55% thinking I could make up for it with extra grains. Low and behold, I only hit a 1.044! Still shy by 6 points. On my typical no-sparge brews I hit anywhere from 66-74% eff. The only thing I could think of was that with all of the flaked grains I used (wheat and oats) that more water was absorbed by them instead of draining into my kettle. I was a bit short on my pre-boil volume when I usually have no problem nailing that with my barley based beers.

Soooo, I see you only used about 1.3 gallons of water for sparging. That to me seems low and I can almost bet that you left some sugars behind in those flaked grains that you could have sparged out with more water. Just my thoughts.

[ziggy]

Make your mash thinner by using more strike water.

Let your mash rest for longer. This is a high adjunct beer and the enzymes in the pilsener malt need more time to convert all that starch from the flaked oats and wheat.

Check your water chemistry. John Palmers nomograph is really easy to use. Try and get your local water report then apply that information to the nomograph. That will at least get you in the ballpark as far as mash pH.

[Bugeater]

1.3 gallons of sparge water is definitely not enough. That left a lot of sugars behind. This becomes a problem when you are trying to step up the temperature that far just with an infusion of water. You have to add so much water to raise the temperature that you can't rinse all the sugars out of the mash. If you can't directly heat your mash tun, you can achieve this rise by doing a decoction mash (heating the thick part of the mash in a separate pot, leaving the wort in the tun) or by stirring the mash with a heat stick or immersion heater.

Another possibility that no one has mentioned is channeling in your mash tun.

Wayne