Dextrin Sugars

[paulpj26]

I was just wondering if someone could clear something up for me. As I have read on the forum and some books, Dextrin sugars are non-fermentable sugars (hence the reason why when we want a sweeter beer we mash at a higher temp in order to gain more of the Dextrin sugars so they don't ferment out (that's my understanding of it which could be totally wrong :rofl: ))

However, what is confusing me is that in GW's book it says that the dextrin sugars will eventually ferment out (which is obviously contradictory to everything else I have read). I do not doubt GW (or anyone else for that matter :thumb: ) so I was wondering do the dextrin sugars eventually become simple sugars which can be fermented?

Probably clear as mud but hey ho :whistle: :

 

[robsan77]

you see, this is why we need aleman

 

[TheMumbler]

Which GW book? In Home Brewing (p53) he talks about brewer's yeast not being able to completely breakdown dextrins. He also comments that brewer's yeast can only attack dextrins very slowly. If you have low yeast populations like those in ale stored in a cool cellar I would imagine that they would struggle to maintain an active colony just breaking down dextrins for sustenance. So, I should think, in practical terms you could view them as being unfermentable. I suspect GW is just being meticulously accurate. That said I don't really know any more than you do so I could be way off the mark here.

 

[broadfordbrewer]

My limited understanding of this is the same as Mumbler explains :thumb:
Like you say Paul, it's all in the Mash temp and therefore the beer style you are trying to acheive,

Dextrin
The unfermentable carbohydrate produced by the enzymes in barley. It gives the beer flavor, body, and mouthfeel. Lower temperatures produce more dextrin and less sugar. While higher temperatures produce more sugars and less dextrin.
(Source: http://beeradvocate.com/beer/101/terms.php)

edit: However, might I add to this, that this theory goes out of the window, when, if like me you have a totally inefficient mash tun, then you need to mash as high as feasibly possible and hope to hell you get some sort of carbohydrate!

 

[graysalchemy]

I have found the next best thing to Aleman









An Old Aleman Post on the subject

clicky

It may be of use it may not my brain is not functioning well today and I'm not up to deciphering all the info, I just searched dextrin and Aleman.

Cheers

AG

 

[paulpj26]

Which GW book? In Home Brewing (p53) he talks about brewer's yeast not being able to completely breakdown dextrins. He also comments that brewer's yeast can only attack dextrins very slowly. If you have low yeast populations like those in ale stored in a cool cellar I would imagine that they would struggle to maintain an active colony just breaking down dextrins for sustenance. So, I should think, in practical terms you could view them as being unfermentable. I suspect GW is just being meticulously accurate. That said I don't really know any more than you do so I could be way off the mark here.

It's in "Brew You Own British Ale" I don't actually have the book on me at the moment so I can't quote. However, the jist of what he is saying is in regards to priming bottles, which he basically states that bottles don't need priming as the dextrin sugars will ferment out to produce "perfect" condition (that's from my memory which is notoriuos for being inaccurate, just ask the wife! :lol: )

 

[broadfordbrewer]

I have found the next best thing to Aleman

An Old Aleman Post on the subject

clicky

It may be of use it may not my brain is not functioning well today and I'm not up to deciphering all the info, I just searched dextrin and Aleman.

Cheers

AG

I should have thought to do that rather than stabbing into the darkness with a pin! :lol:

 

[paulpj26]

I have found the next best thing to Aleman









An Old Aleman Post on the subject

clicky

It may be of use it may not my brain is not functioning well today and I'm not up to deciphering all the info, I just searched dextrin and Aleman.

Cheers

AG

Thanks AG :thumb:

So if my understanding from Alemans post is correct, dextrin sugars aren't fermentable, so I'm a little lost as to what GW is talking about :wha: :

T

 

[Aleman]

This is one of those things that occasionally Graham contradicts himself on.

'Dextrin' refers to any short chain carbohydrate consisting of 3 or more glucose units. Maltotriose (3 Units of glucose) is slowly fermentable by lager strains, but not by ale strains. Dextrins with 4 or more glucose units are not fermentable by either Saccharomyces cerevisiae (Ale Yeast) or S uvarum (lager yeast).

I have fallen foul of his pronouncement that a properly brewed beer will generate adequate condition without priming before. I now prime all my beers . . unless I stop the ferment early and leave a couple of gravity points remaining in the beer.

The unfermentable carbohydrate produced by the enzymes in barley. It gives the beer flavor, body, and mouthfeel. Lower temperatures produce more dextrin and less sugar. While higher temperatures produce more sugars and less dextrin. (Source: http://beeradvocate.com/beer/101/terms.php)

That is the wrong way round Lower mash temps produce less dextrins and higher mash temps more . . . beware of information found on the internet, it may not be accurate . . . although you would expect an author to get it right as well :lol:

 

[broadfordbrewer]

This is one of those things that occasionally Graham contradicts himself on.

'Dextrin' refers to any short chain carbohydrate consisting of 3 or more glucose units. Maltotriose (3 Units of glucose) is slowly fermentable by lager strains, but not by ale strains. Dextrins with 4 or more glucose units are not fermentable by either Saccharomyces cerevisiae (Ale Yeast) or S uvarum (lager yeast).

I have fallen foul of his pronouncement that a properly brewed beer will generate adequate condition without priming before. I now prime all my beers . . unless I stop the ferment early and leave a couple of gravity points remaining in the beer.

The unfermentable carbohydrate produced by the enzymes in barley. It gives the beer flavor, body, and mouthfeel. Lower temperatures produce more dextrin and less sugar. While higher temperatures produce more sugars and less dextrin. (Source: http://beeradvocate.com/beer/101/terms.php)

That is the wrong way round Lower mash temps produce less dextrins and higher mash temps more . . . beware of information found on the internet, it may not be accurate . . . although you would expect an author to get it right as well :lol:

That's scary :shock: .... and the last time I'll be straying from this forum to find an answer! Cheers Aleman

 

[TheMumbler]

*deletes text* AM renders my speculation irrelevent.

That quote doesn't say temperature of what btw. I guess if you were baking your beer it might be true

 

[paulpj26]

Cheers Tony for clearing that up :thumb:

Funny I've just been reading about Maltotriose etc in Designing Great Beers by Ray Daniels, my eyes slowly became bozeyed! :rofl:

I do prime my bottles now as I never got any proper condition when I didn't (for the above reasons)

 

[unclepumble]

Further to alemans post, it is possible to convert the unfermentable dextrins to less complex and therefore more fermentable sugars by adding AMG (amyloglucosidase) to the fermenter.

"The addition of Glucosylase to the fermenter converts the unfermentable dextrins to glucose which in turn is fermented to alcohol giving an apparent attenuation higher than 100% without loss of palate fullness or head retention. At the same alcohol concentration as a normal attenuated beer the super-attenuated beer will have required 25% less of raw material."

You can get Pilsner powder, from HB Shops tis pretty much the same stuff.

It is possible to save a beer that has stopped fermenting by adding AMG also but it is a risky practise.

UP

P.S. Good to have you back Tony :thumb:

 

[jamesb]

Further to alemans post, it is possible to convert the unfermentable dextrins to less complex and therefore more fermentable sugars by adding AMG (amyloglucosidase) to the fermenter.

Interesting. I always assumed it was used either in the mash or the lauter tun.

Guess it makes sense though in the fermentor.

 

[Aleman]

Further to alemans post, it is possible to convert the unfermentable dextrins to less complex and therefore more fermentable sugars by adding AMG (amyloglucosidase) to the fermenter.

Interesting. I always assumed it was used either in the mash or the lauter tun.

Guess it makes sense though in the fermentor.

Not really, as there is nothing to tell it when to stop . . . AMG will sit there gradually chewing on what it finds, thinning out the beer and if bottled allowing the yeast to continue fermenting and producing CO2 with disastrous consequences. Its a handy trick employed by mega breweries to obtain more alcohol for less ingredients because they will pasteurise the beer . . .stopping the action of AMG. Very risky in the homebrew arena.

I have thought about making a traditional porter (1/3 Pale, 1/3 Amber 1/3 Brown malt) which of course would require additional enzymes in the mash for it to work. . . . Murphys make something called Biase (AMG and Glucanase IIRC) that is designed to be used inteh mash

 

[Duncs]

'Dextrin' refers to any short chain carbohydrate consisting of 3 or more glucose units. Maltotriose (3 Units of glucose) is slowly fermentable by lager strains, but not by ale strains. Dextrins with 4 or more glucose units are not fermentable by either Saccharomyces cerevisiae (Ale Yeast) or S uvarum (lager yeast).

But there is a yeast that can ferment dextrin http://www.ncbi.nlm.nih.gov/pmc/articles/PMC204282/pdf/aem00115-0127.pdf wonder what kind of beer it would produce :hmm:

 

[paulpj26]

I imagine a very thin beer and probably not much in the way of flavour

:

 

[Aleman]

'Dextrin' refers to any short chain carbohydrate consisting of 3 or more glucose units. Maltotriose (3 Units of glucose) is slowly fermentable by lager strains, but not by ale strains. Dextrins with 4 or more glucose units are not fermentable by either Saccharomyces cerevisiae (Ale Yeast) or S uvarum (lager yeast).

But there is a yeast that can ferment dextrin http://www.ncbi.nlm.nih.gov/pmc/articles/PMC204282/pdf/aem00115-0127.pdf wonder what kind of beer it would produce :hmm:

While it can I think it's important to realise that they are talking about using it to produce fuel ethanol . . . not beer. Turbo yeasts produce ethanol . . . I'm not sure that I would want to use them to make beer. . . . Pediococcus produces ethanol . . . but really crappy beer.

I'll stand by my earlier claim Yeasts for beer production cannot ferment dextrins of more than three or 4 glucose units long

 

[Duncs]

Pediococcus produces ethanol . . . but really crappy beer.

I'll stay away from ****'s then :lol: