Mashing and Sweetness

I know that mashing toward the upper end of the range produces a "thicker" beer, or higher FG, and mashing at the lower end produces a thinner or dryer beer. However, the term "sweeter" is often attributed to the higher mash temps as well. I am just curious how much sweeter?

I am working on a cream/sweet stout recipe, and some people that I know are lactose intolerant, so was considering just doing a high temp mash to get the sweeter flavor. Will this work, or does the effect of a higher mash just provide a more full mouth feel, and only a hint of sweetness?

Also, how to I take into account the IBUs of the hop contribution of wort that is mashed at different temps? 30 IBUs with an FG of 1.010 vs 30 IBUs with an FG of 1.020 probably would be perceived quite differently right?

To say it is sweeter is at the least an incomplete or over-simplified description if not a misleading one. Higher mash temps leave more longer chain sugars than lower temps and some of those larger molecules may be left unfermented in the finished beer. This will leave more "body" as those big molecules are still in beer and bouncing around in your mouth when you drink it. They do contribute to a residual "sweetness" but it's not a simply, sugary sweetness but broader and less sharp if that makes sense. You might also consider the use of some additional crystal malts or even special versions like Honey Malt to boost the sweetness of the beer. A small vanilla addition can also enhance perceived sweetness.

Not to jack the thread, just wanted to say I'm glad to see this answer here, my first few all grain beers were mashed lower, ended up around 150, and tasted quite sweet. I did a couple more that were mashed up around 156/157, and barely tasted sweet at all. Had me worried, but they are turning out, and this tells me why. Thanks BigEd!

Kosch

Not to jack the thread, just wanted to say I'm glad to see this answer here, my first few all grain beers were mashed lower, ended up around 150, and tasted quite sweet. I did a couple more that were mashed up around 156/157, and barely tasted sweet at all. Had me worried, but they are turning out, and this tells me why. Thanks BigEd!

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Kolsch, you may want to read BigEd's information again. You have it backwards. Higher mash temps lead to more long-chain sugars and more malt sweetness in the final beer because the yeast can not digest these long-chain sugars. Lower temps promote more short-chain, simple sugars that the yeast easily eat, leaveing less residual malt sweetness.

There are more factors that can result in residual malt sweetness than just mash temp, so the fact that you got more malt sweetness at a lower mash temp, and less at a higher mash temp was due to a factor other than mash temp!!

BigEd,

Thanks for the info. What you say agrees with most of what I've read. What about my last question about bitterness though?

I notice from the BJCP guidelines that in a sweet stout: "...The sweetness in most Sweet Stouts comes from a lower bitterness level than dry stouts and a high percentage of unfermentable dextrins. Lactose, an unfermentable sugar, is frequently added to provide additional residual sweetness..."

From the BJCP guidelines, a Sweet Stout usually has a bitterness range of 20-40 IBUs. I am curious why Lactose is added rather than simply reducing the bitterness further? Does lactose provide a specific flavor that is perceived as "creamy?" I have never used it.

I like your idea about using a touch of vanilla to increase the perception of sweetness, and perhaps a barely perceivable addition of vanilla would also offer the perception of "creaminess" that would be expected from lactose?

...I am curious if there is any scientific information available that describes the human perception of taste, with respect to different kinds of sugar.

Dextrins are not necessarily perceived as "sweet." For example CaraPils adds dextrin to the beer, which increases body, mouthfeel and head retention. However, it is hardly perceived as sweet.

Are longer chain, "complex" sugars "less sweet" than simpler sugars like fructose and glucose? Does the human perception of sweetness align with yeasts ability to ferment a particular sugar? ie. the more fermentable the sugar, the sweeter it would seem, and vice versa?

...Just did a quick search and came up with this: http://en.wikipedia.org/wiki/Sweetness

...also: http://beersmith.com/blog/2009/09/26/balancing-your-beer-with-the-bitterness-ratio/

TopherM said:

Kolsch, you may want to read BigEd's information again. You have it backwards. Higher mash temps lead to more long-chain sugars and more malt sweetness in the final beer because the yeast can not digest these long-chain sugars. Lower temps promote more short-chain, simple sugars that the yeast easily eat, leaveing less residual malt sweetness.

There are more factors that can result in residual malt sweetness than just mash temp, so the fact that you got more malt sweetness at a lower mash temp, and less at a higher mash temp was due to a factor other than mash temp!!

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"They do contribute to a residual "sweetness" but it's not a simply, sugary sweetness but broader and less sharp if that makes sense"

That's what I was referring to (and sorry I didn't clarify, meant the wort, not the final beer). It goes along with what the OP just posted about perceived sweetness, so based on what BigEd, I would take it as simple sugars tasting sweeter, where as complex sugars taste less sweet.

Thanks ryangibson77 for posting your additional findings as well

ryangibson77 said:

I am curious why Lactose is added rather than simply reducing the bitterness further? Does lactose provide a specific flavor that is perceived as "creamy?" I have never used it.

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Because they are two different things. Reducing hop bittering doesn't make a beer any sweeter it makes it less bitter. While that may increase perceived sweetness adding the lactose does add actual sweetening and some body. Understand, however, that the flavor & sweetness of lactose is different and less sweet than sucrose.