4VG and flavor in wheat beer

I dug this out of an old HBD while researching hefe style for my next brew. Any thoughts? Has anyone played with these variables to maximize clove flavors?

Date: Thu, 6 Dec 2001 16:39:18 -0500
From: "Steve Alexander" <steve-alexander at worldnet.att.net>
Subject: re: wheat yeast flavor

Art McGregor asks ...

>Every time I brew a wheat beer (extract based) the wheat flavor from the
>yeast only lasts a few batches, then fades away.
[...]
>Is this a common problem?

This is a weird one Art. The clove-like weizen flavor is from 4
vinyl-guaiacol(4VG) and is created by the yeast from a phenolic precursor
from the grain called ferulic acid. Many yeasts can perform this
conversion - probably most wild yeasts.

It's possible your strains have lost their ability to produce 4VG but that's
quite unlikely. It's most likely a problem in the wort level of ferulic
acid or in the fermentation conditions.

If you were a masher rather than an extract brewer I'd suggest you perform a
rest at around 44C to increase the amount of ferulic acid extracted from the
grist. As an extract brewer you are at the mercy of the vendors to include
enough ferulic acid to make a tasty weizen. I'd experiment with the choice
of extracts, Art. Also perform a healthy boil. The boil actually converts
enough ferulic to 4VG to be almost tastable. This leaves less for the yeast
to do.

Perhaps George DePiro will comment on it, but he under-pitches weizen yeast
to get optimal flavor and starts his fermentations cool (low 60sF), and
allows them to increase to around 70F after fermentation starts.

4VG is also not temperature stable so the clovey flavor fades over a period
of months. Keeping the beer colder helps preserve it.

-S

Click to expand...

I just brewed a hefe over the weekend.. horrible efficiency ~55%...need more rice hull and stirrer/masher on my next brew dunkle weiss.

Anyways, from all the readings and people sharing... Here's what I know
use WLP300 or equivalent....

More banana: ferment at higher temp (~low 70s) and underpitch the yeast.
More Clove: ferment at lower temp (upper 60s) and overpitch the yeast.


I think it is a delicate balance between the yeast and temp... enjoy. I'm doing a dunkle this weekend....

My mind is also thinking of how to maximize flavor from the dry yeast for wheat beers. I read DrGonzo's comparison between the two available strains and he felt both were less stellar than the liquid:

Last night my good friend Jeff and myself decided to taste these freshly carbed and tapped beer. Here are our tasting notes

WB-06
Cloudy with a thick white head, straw colored. Aroma is a bummer as there is a slight hint of sulfur and no clove or banana. Taste is very clean with a small trace of citrus and just a touch of perle hops. The mouth feel is very light and it has a very clean finish but the citrus tang lingers. Final grade 1-5 5 being the highest.

Dan gives this beer a 2.
Jeff gives this beer a 1.5.

Thoughts: This will be ok for beer pong, but is a far cry from the delecious hefeweizens I make using liquid yeasts wlp 380 hefe iv or Wyeast 3068 Weihenstephan.

Danstar Munich
Slightly cloudy(almost clear)1 finger of thick white head, Golden color. Aroma as the slightest hint of clove and touch of bread. Taste is very clean with a touch of breadiness. Mouth feel is light and the finish is crisp.

Thoughts: This is spot on for an American hefe but nowhere near a German hefe. I would consider using this yeast again but not the WB-06.

Dan gives this beer a 3.
Jeff gives this beer a 3.

Click to expand...

Can I maximize the flavors using a dry yeast by focussing on the other factors?

-111 degree rest (44c)
-strong boil to convert ferulic acid to 4VG
-temperature control (60s for the wort, not the ambient)

I may have to do 10 gallons and split it to assuage my curiosity. Go Danstar Munich vs Whitelabs or Wyeast.

And, as is my new custom, go read what Kaiser has to say!

My experience with the clove flavor is that you want to use a yeast that is good at producing it. Wy3068 or wlp300 (which is supposed to be the same strain) are good choices. I don't know about the dry strains as I haven't used them yet. I have heard a lot of bad things about them though.

Even mashing without the ferulic avid rest should give enough clove charachter to the beer if the proper yeast is used but a rest at 44c can greatly enhance this. My next weissbier will be brewed with that rest and I'll compare it to my last batch which was brewed without this rest.

Kai

I was looking for a thread on probrewer to find a reference for the slightly interesting factoid that there is more ferulic acid (4VG precursor) in barley malt than in wheat malt when I came across this even more interesting nugget:

Øl-sheik said:

Do you like Vanilla? then give your Weizen some time ;-)

In this study the decrease of 4-vinylguaiacol (4VG) during beer aging was investigated and the products that arise from it were identified. Two compounds, vanillin and apocynol, were identified in beer model solutions after forced aging and in naturally aged beers by GC-MS and HPLC-ECD analyses. Both account for up to 85% of the decrease of 4VG. Only in the presence of substantial amounts of oxygen in the bottle headspace was vanillin detected. Apocynol [4-(1-hydroxyethyl)-2-methoxyphenol] was found to be the main degradation product, and its formation was shown to be highly dependent on the beer pH. Because both apocynol and vanillin have a clear vanilla-like aroma, the decrease of 4-vinylguaiacol during beer aging might impart a shift from a clove-like aroma in fresh specialty beers (such as wheat beers and other top-fermented blond or dark ales) to a sweeter, more vanilla-like flavor impression of aged specialty beers.

from: Journal of agricultural and food chemistry. 2008 Dec

Click to expand...

Yes that's what I also told Jamil and he had a hard time believing it.

Some brewers think that the clove is somethinbg that comes from the wheat as it is generally only found in Wheat beers. But that is not true. It's a property of the yeast (being POF+ - phenolic off flavor positive) and you'll also get the clove in barley based worts. One exampe is Dampbeer, a fairly unknown German beer style that is brewed with all barley malt and fermented with Weissbier yeast. Some call it the poor mans Weissbier.

Kai

You all have me deep in thought.... Thanks for the info.

DrGonzo (quoted above) likes wheat beer just a little bit (VERY PASSIONATE ABOUT IT!) and he also pointed me toward this thread on the northern hombrewer to read.

First thing I noticed was the rule of thirty degrees being applied for the ferment (pitch temp plus ferment temp) And the 111 degree rest. Should be good reading, I hope. Off to do some research (liquid based, that is, then more reading!)

I know this is a really old thread. I am writing this from UC Davis coming up on 4 weeks in out of my 18 week program, so any writing like this is great practice for my big exam, bare with me:

According to Charlie (Dr. Bamforth) and Dr. Lewis an amount of the signature "clove" flavor comes from the yeast, but a large amount is dependent on a grain based precursor or from 4VG (from ferulic acid) as chefmike stated. However, ferulic acid is not (in noteworthy amounts) free floating in malt. Ferulic acid is mostly only found in grain bound to arabanoxylan in the cell walls of plants (mostly those of the cell walls in the endosperm surrounding &#946;-glucans on either side, also the aleurone layer (where the majority of enzymes are synthesized during germination) has cell walls with a much greater proportion of xylan to &#946;-glucan) which is not of particular interest in mashing). The arabnoxylanases (xylanase) will put ferulic acid into suspension where another enzyme (ferulic acid decarboxylase), usually in certain yeast, will be able to remove the carboxyl (COOH) group to and result in CO2 and 4-vinyl guaicol AKA clove flavor/aroma.

OK, so here is the rub, the xylanase is only present in notable amounts while germinating the barley (or wheat, and wheat has a LOT more arabanoxylan than barley) during malting and is highly denatured during the kilning (even of pale malts). So if you want to have a decent amount of clove in your wheat beer stick to these things:
Use higher modified malts (>than ~120 DP)
Stick to malted wheat vs torrified/raw wheat (no enzyme production = unbroken down arabanoxylan)
Use the proper yeast.
NO a protein rest will not do anything to help this flavor (and there is even major controversy over if a protein rest actually breaks down protein at all).
Yes, decoction mashing will help because the high temp will break down the arabanoxylan structure.
And finally, and I will say this often to homebrewers, USE MORE YEAST! for a couple bucks more you can make such better beer by just adding more yeast!

Cheers, we are all here to make better beer, right?

What is the optimum temp for xylanase?

Xylanase is denatured during the kilning phase of the malting process. If any does survive, it will be destroyed quickly in the mash due to its heat sensitivity.