Troubles with Raw Wheat

[Agent]

So like most here, I don't have issues doing extra work or steps just so I can use common or cheap ingredients. Which means when I found a 50 lb sack of hard white spring wheat berries for $20-something, I snagged a bag knowing that it would come in handy brewing.

A little research told me that though raw wheat needed to gelatinize before conversion, but that it occured at a temperature between 125F and 150F, so during normal mashes. I was skeptical, but tried it. I got 0 additional gravity points from the wheat.

A second round, I attempted a cereal mash where I milled some barley and wheat together, heated to 120F for 20 mins, then 150 for 30 mins, then slow boiled for another 30 mins stirring while the whole thing turned to sticky wheat goo. I got little detectible gravity points from the wheat again.

Third round, I put about 2.5 lbs milled wheat with approximately two parts water in a pressure cooker (internal container to keep from scorching) and cooked that for an hour at 10-15 psi. All water was absorbed into the wheat, and I didn't have the gelatinous goo like last time. Yet again, I got negligible gravity points for my efforts.

All of these processes were in conjunction with a 60 minute mash.

I'm at a total loss for the next reasonable step to get any gravity points from my wheat, so any help is greatly appreciated at this point!

 

[RM-MN]

What else are you using in your mash? I find that I can convert the wheat starches with some pale malt, at least half unmalted wheat and with most pale malts I can go to about 60% unmalted wheat and get full conversion. The key is that you need a base malt with enough diastatic power to provide the enzymes for the conversion. You cannot do it with malt extract.

 

[Agent]

My first try was 65% 2-Row, and my last two recipes used about 55% 2-Row, and 20-30% Wheat malts.
It seems like there should be enough enzymes present to at least convert a portion of the raw wheat, though my next attempt may involve a 90 minute mash just to see.

 

[RM-MN]

My wheat all converted in a 30 minute mash. Yours might take longer depending on the milling. Mine was milled very fine. Wheat is difficult to mill properly in a crusher mill because it is smaller and harder than barley so you might not have gotten a good milling. Mine goes through my Corona style mill which handles it very well.

 

[BrewerinBR]

Wheat starch will gelatinize between 125.6 and 129.2 F in the presence of water. The ratio of water to grain I use is 2 quarts per pound of wheat. The finer the wheat is ground the better. You will need to keep it at these temps for at least 30 minutes. Do not allow it to cool, add 1 or 2 LBS of 6-row to this after the 30 minutes and raise to 151 to 153 slowly, stir it constantly. Maintain 151 to 153 for 30 minutes. It is not necessary to boil wheat, but if you wish to use the cereal mash the step up to sacrification rest in the main mash as I do then bring it to a rolling boil and add to main mash. Boiling will thicken the ungelatinized starch so you may need extra water to keep it liquid enough to be usable. You will also need to figure out just how much of a cereal mash you need to increase the main mash to sacrification rest.

Good Luck

 

[Agent]

Thanks for the help folks!
I too mill using a Corona mill, and use a fairly fine crush. I actually tighten it up a bit for the raw wheat. When I pressure cooked the last batch, the grain pieces had swollen up quite substantially, so maybe even finer is in order?
So I just want to make sure I'm not running off any ridiculous assumptions, but does the gelatinization of wheat starch ONLY occur in those temperature ranges you listed, START there, or OPTIMALLY occur there?
Lastly, QBrew has my estimated yield of Flaked Wheat at about 1.034 ppg. Is this a reasonable extraction estimate for raw wheat, or should I be anticipating much lower yields?

 

[strangegreenman]

What I have heard is that when dealing with raw wheat, a separate cereal decoction mash helps before adding the wheat to the main barley mash. Perhaps conducting a 10 minute beta-glucan rest (110F) might also help.

There's advice about it here: http://thebrewingnetwork.com/shows/985