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Can you get ferulic acid from Weetbix?

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frankvw

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I've brewed a Weizen from extract before and it wasn't bad, but the liquid wheat malt extract I have yields a clear, light bodied beer that is low on the typical Weizen flavors. This is not surprising, since the LME lacks a lot of things you get from a proper mash containing significant amounts of wheat, and is almost devoid of proteins. In fact, on the tin it says the stuff has been "kettled for optimum clarity" and conversely the beers brewed with (and no additional grains) it are very poor in head formation and retention.

However, some fellow home brewers tell me that they have had encouraging results by using a few bricks of Weetbix which they boiled, cooled and then added to the fermenter. I can see how this could add a little bit of body, mouth feel, cloudiness (due to protein) and a bit of wheat flavour. (There is of course no conversion taking place here; we're just leeching some starches, proteins and flavours out of the Weetbix.)

Which makes me wonder: if I steep Weetbix in water at ferulic acid red temperatures (109–113 °F / 43–45 °C), could I get some ferulic acid from it? As I understand it, Weetbix is pre-cooked (the human digestive system being unable to digest raw wheat) but I'm not sure if, and how, that would affect ferulic acid availability. I understand that in wheat the ferulic acid is found bound to cell wall polysaccharides. Will the processing that the wheat has undergone during the production of the Weetbix affect that in any way and, if so, how?

(And yes, I know that I'll get a much better beer from a proper partial mash. But that's not what I'm asking here; I'm curious if anyone has ever tried to use Weetbix in this way and if it resulted in some ferulic acid availability.)

Curious to know your opinions!
 

Vale71

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The short answer is: don't do it.

The long answer is:

- you get ferulic acid from barley malt and not wheat malt, you don't get phenolic esters in regular barley beers because of the yeast used for regular beers not being able to convert it to 4-vinyl-guajacol
- you need enzymes to set it free (=malt)
- the starch you'll be extracting and not converting is not good for your beer
 
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frankvw

frankvw

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- you get ferulic acid from barley malt and not wheat malt,
- you don't get phenolic esters in regular barley beers because of the yeast used for regular beers not being able to convert it to 4-vinyl-guajacol
- you need enzymes to set it free (=malt)
- the starch you'll be extracting and not converting is not good for your beer
Thank you for your answer. However, I'm not sure about some of things you say here. A few remarks, if I may:

1. Both barley and wheat contain ferulic acid (which is technically a phenolic phytochemical). But in order to act as a precursor to 4VG (4-vinyl guaiacol, the clove-like phenol desirable in Weizen) it must first be released. Ferulic acid is freed from the malt during mashing by enzymatic activity, but only within the temperature zone known as the ferulic acid rest. In barley malt beers most of the 4VG is produced during the boil by means of thermal decarboxylation of precursors derived from the malt (mostly FA). In wheat beers on the other hand most of the ferulic acid is hydrolyzed during fermentation, causing higher 4VG levels in these beers. Why this is the case is not entirely understood as far as I can determine. The most likely scenario is that other malt components (which are different for malt and barley) play an either catalytic or inhibiting role, but the jury seems to be still out on that one, so your guess is as good as mine.

2. There is no such thing as "phenolic esters". Phenols and esters are entirely different things. Phenols are either formed during the boil by decarboxylation of precursors, or during a fermentation with POF+ yeasts. (This is not entirely true; all yeasts produce phenols to some extent, but with POF- yeasts these usually remain below the flavor threshold.) Phenol formation is not a factor of fermentation temperature to any significant extent; it is rather a factor of wort components at the start of fermentation and yeast genetics. Esters, on the other hand, are formed about 2-3 days into the fermentation from organic acids and higher alcohols, and this process is a factor mostly of fermentation temperature but also of DO, pitching rates, yeast genetics and various others.

3. The use of wheat malt does have a marked effect on 4VG formation. If you have ever brewed Belgians with POF+ Belgian yeasts, you will know that even a little bit of wheat malt in the grain bill can have a marked effect on the formation of spicy phenols.

4. You are quite correct in saying that enzymes are essential for the release of FA. However, this is a two stage process. Enzymatic activity during the FA rest in the mash are responsible for the release of FA at that time. However, there is an additional release of ferulic acid during fermentation of wheat beers, which are believed to stem from the activity of feruloyl esterases produced by the yeast.

5. Starch in beer is generally not a good thing, I absolutely agree with you there. However, there are certain specific scenario's where a small amount of starch can be beneficial, such as pulling an extract-Weizen brewed from poor malt extract more into the direction of a "proper" Weizen. I agree this calls for protein more than starch, but this is something like instant coffee being closer to real coffee than pure water is. A beer like this is never going to be on par with an all-grain Weizen no matter what you do. That said, perhaps a bit of wheat protein might be extracted from the Weetbix.

Just my five cents.

That said, I'm still wondering if I could get ferulic acid from Weetbix given the way the wheat has been processed in the manufacturing of that product. Because that question remains as yet unanswered. :)
 

RPh_Guy

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the LME lacks a lot of things you get from a proper mash containing significant amounts of wheat, and is almost devoid of proteins. In fact, on the tin it says the stuff has been "kettled for optimum clarity" and conversely the beers brewed with (and no additional grains) it are very poor in head formation and retention.
That must be from your particular product and/or process. The LME that I've used produced beer with great head retention and lacing.
Ferulic acid is freed from the malt [...] only within the temperature zone known as the ferulic acid rest.
Sorry, that's just not true.
The wort has plenty of ferulic acid, regardless of whether a ferulic acid rest is performed.
 

Vale71

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The wort has plenty of ferulic acid, regardless of whether a ferulic acid rest is performed.
That is correct as cytolysis will have occured during the malting process thus setting some ferulic acid free even before mashing.

However in this particular case if using raw cereal you'll need enzymatic activity as no malting has taken place and if you're adding the unmalted cereal to an LME wort then you obviously won't have any enzymes available.
 
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frankvw

frankvw

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You're right, the correct term is phenol esters. English is only my second language, sorry.
I sit corrected. I was not aware that the esterification of phenols plays a significant role in brewing. It was my understanding that phenols are not involved to any appreciable degree in the formation of esters in beer.

Do you perhaps know where I can read up more on that? You've sparked my curiosity. :)
 
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frankvw

frankvw

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That must be from your particular product and/or process. The LME that I've used produced beer with great head retention and lacing.
You're right. The LME we have access to here in SA is rubbish compared to what is available in Europe and the US.

The wort has plenty of ferulic acid, regardless of whether a ferulic acid rest is performed.
In that case, why is that a ferulic acid rest is widely considered to be so important in Weizen brewing when it comes to the formation of 4VG? Keeping in mind that unmalted wheat tends to be a minor portion of the grain bill, if there is any at all.
 

RPh_Guy

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In that case, why is that a ferulic acid rest is widely considered to be so important in Weizen brewing when it comes to the formation of 4VG? Keeping in mind that unmalted wheat tends to be a minor portion of the grain bill, if there is any at all.
I have yet to employ an acid rest. I use WLP300 and get LOTS of both banana and clove in my weizens (40% pale malt, 60% white wheat malt) by controlling fermentation variables. I've also gotten lots of clove from certain Belgian strains without an acid rest.

So who considers the acid rest "so important" and why? My guess is that it's mostly tradition stemming from use of less modified malts. It's definitely not needed. I suggest you make some adjustments on the cold side if you aren't getting the flavor profile you want. Putting cereal biscuits in the kettle won't fix it.

Sorry your LME sucks. :(
One more reason to go all grain?
 
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frankvw

frankvw

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OOoookay.... My main question has been answered via different channels, and the verdict is that regardless of whether the use if Weebix in a beer is a good thing or not, and regardless of whether a ferulic acid rest is useful or not, a ferulic acid rest when using Weetbix would be pointless, because the wheat used in Weetbix has been cooked, which denatures the enzymes that liberate the ferulic acid from the grain cell wall polysaccharides to which it is bound.

I should have seen that. :oops:

Time for a beer.
 
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