Take the 2-minute tour ×
Homebrewing Stack Exchange is a question and answer site for dedicated home brewers and serious enthusiasts. It's 100% free, no registration required.

I read in some sources that mash conditions can influence the production of dextrins, that are not fermentable, have no taste (is that correct?) and add body to the beer. But somewhere else I read that mash conditions can contribute to sweetness (for example with decoction mash), what kind of compounds are produced during mash that will give some malty flavor or sweetness in finished beer?

share|improve this question
    
Could you provide some links to where you read these? –  Nathan Koop Mar 25 '13 at 16:18
    
byo.com/mashing/item/…, The Complete Joy of Homebrewing - C. Papazian plus some others I do not remeber –  Paolo Mar 25 '13 at 16:23
add comment

3 Answers

up vote 3 down vote accepted

The mash temperature specifically doesn't really make for a sweeter beer. While adjusting mash temperature allows the brewer to control the balance of simple (fermentable) sugars and dextrins (unfermentable), increasing either doesn't produce a sweeter beer:

  • increasing simple sugars doesn't make the beer sweeter - primarily any sweetness from these sugars is lost when they are fermented.
  • increasing dextrins doesn't increase sweetness considerably, because dextrins are not all that sweet. Dextrins have around 5-10% the sweetness of table sugar.

You may be thinking of melanoidins. These are a class of Maillard reaction compounds - of which there are many, with flavors like bready, malty. Some say richer, sweeter, but not like candy. They are produced with heat in addition to amino acids, proteins and carbohydrates. The high temperature of a decoction mash increases the rate of production of melanoidins. You can also emulate the effect with (Weyermann) Melanoidin Malt, aka Aromatic Malt from other malters.

share|improve this answer
    
Great answer. THank you :) –  Paolo Apr 1 '13 at 17:55
add comment

Note: I am not a chemist. My homebrewing understanding is along the lines of:

Mashing at a higher temperature will promote the alpha-amylase enzyme to breakdown the sugars, while mashing at a lower temperature will promote the beta-amylase enzyme to breakdown the sugars.

The alpha-amylase will produce dextrins which will contribute to sweetness and body.

The beta-amylase will produce fermentable sugars, hence more alcohol.

share|improve this answer
    
This is interesting and a great practical description of why the temperature balance is so important! –  trisweb Mar 26 '13 at 1:36
add comment

Sweetness is pretty much dependent on recipe, not mashing. Using crystal malts or reducing hops will emphasize sweetness. Manipulating mash temps will mainly affect body and mouthfeel.

share|improve this answer
1  
Also, a low attenuation/high flocculation yeast will help with residual sweetness. –  Tobias Patton Mar 25 '13 at 18:34
    
Also as is done in popularmechanics.com/home/how-to-plans/… you can pull off some of the mash and caramelize it which will make it unfermentable and add residual sweetness. Also I think adding lactose would add residual sweetness because it isn't fermented by yeast. –  Chris Plaisier Mar 28 '13 at 20:20
    
If by puling off the mash and caramelize it you mean decoction, there are mixed feelings about it. There are a lot of people who feel that doesn't make a difference. My own experimentation seems to confirm that. You can take some of the wort and boil it down to caramelize it to add sweetness, but obviously that's not done in the mash. –  Denny Conn Mar 29 '13 at 17:52
    
The linked recipe describes a process where some of the first runnings are boiled until reduced to a syrup. Probably won't reach the required temperature to caramalize the sugars, so I doubt this will affect the fermentability of the wort. –  Tobias Patton Mar 30 '13 at 15:26
    
My experience is that if you boil it down enough, you can achieve caramelization temps. But I haven't found that to be really different than not boiling it quite that far. And as noted, it isn't happening in the mash. –  Denny Conn Mar 30 '13 at 20:20
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.