Thick Stouts

Great question. I don’t have the answer. But The Bruery is my favorite place to get beer from and all their stouts seem to be thin. Which is my only complaint.

 

Maltodextrins.

 

Is it a mystery? No.

There are a lot of factors that can affect the perception of thickness in a big stout. Things such as: mash temp, grist composition, original/final gravity, attenuation, fermenables/non-fermentables, etc. all play a role in that type of mouthfeel.

It’s not just one thing and it can’t be found on a label. You just have to try commercial examples and find the ones you like.

 

Residual sugars. Many imperial stouts have a very high finishing gravity. Just for an example, I know Dark Lord finishes at 1.060-ish gravity, and that is basically the sugar content of a normal pale ale; before it's even fermented.

 

A lot of things.

And stuff.

 

Residual sugars often combined with the use of oats, wheat, and flaked barley. Sugars and high protein content seem to be the two biggest contributors to a thick mouthfeel to my knowledge.

 

That's so helpful.

 

So . . . basically this:

All kidding aside, perceived mouthfeel is multifactorial in nature. Sure, residual sugar (residual extract) can make a beer "thicker". This ranges from anything from malt-derived sugars like maltotriose to sugars added by the brewer that most common beer yeast can't metabolize like lactose or maltodextrine.

Then you have compounds like the beta-glucans which adjuncts like oats are high in. It creates a "smooth" or "soft" mouthfeel, made famous by oatmeal stouts.

And you also have yeast derived compounds like glycerol and esters. The sweetness and fruitiness of many esters can contribute to a beer feeling more substantial, as can the flavor and aroma neutral contribution of glycerol.

Lastly, carbonation level affects the perception of body. Lower carbonation will give you an increased thickness, as well.

Got all that?

There'll be quiz at the beginning of next class.

 

Increased residual sugar. (i.e. how much sugar is left in the beer after fermentation)
Alcohol creates the perception of thickness.
The addition of adjuncts (i.e. oats, wheat)

 

How do you mean?

An increase in the level of alcohol in a beer will make a beer thinner, if all other things are equal.

 

Some references to it here: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1993.tb01143.x/pdf

Not sure of the science behind it. My understanding is that increased alcohol creates the perception of a fuller beer.
I'm sure there are other contributing factors, like the type of sugar fermented to produce said alcohol. For example, short chain sugars (like table sugar) are consumed more easily by yeast and result in a thinner beer.

 

Neat study. Thanks for posting it!

Interesting bit, this:

German "diet bier" is designed for diabetics and has a
relatively high alcoholic content of about 4.75% by weight
and no carbohydrates. Narziss claimed that the high alcohol
content in these beers increases the palate fullness. When
the ethanol level becomes too low, there is a danger of
making an "empty" and imbalanced beer. Similarly, wines
of very low ethanol content (< 10% by volume) are "thin,
low in body, and of low viscosity, whereas table wines of
high ethanol content (> 12%) are full in body".

When Langstaff et al. correlated the alcohol content of
30 commercial beers with 9 sensory terms they found only
weak correlations with the fullness terms (density and
viscosity) and the afterfeel terms (oily mouthcoat, astringency
and stickiness).

The evidence stated above is inconclusive as to the
contribution of alcohol to the sensory effect of mouthfeel.

 

At only 50 IBUs I dont think Dark Lord could have a finishing gravity of 1.060. That would be syrupy sweet and I dont remember it being that way.

 

IBU is not the only factor in balancing sweetness. Black/roasted grains also impart bittering/drying aspects to stouts. Besides, it's been tested by numerous people already. (Not my pic)

 

I love beers like Ten Fidy and Founders Imperial Stout that are mass produced, but just thick as hell. I cannot stand thin stouts..

Looking at you, "Brown" Tuesday..

 

I maybe missed something in that linked article (which was a little more scholarly than I really wanted to wade through this AM), but one example used in support of 'alcohol makes beer have a thicker feel' was that in very light beers retaining a higher than would be expected ABV contributes an illusion of a thicker mouthfeel.

 

I’m going to assume OP is speaking about big stouts.

As to why not all breweries can nail that mouthfeel...any decent brewer know what gives a beer a thick mouthfeel. Actually pulling it off is a little bit different.

Although, the exact number may be debated, there really is a sweet spot for big beers’ finishing gravity (and a different one for barrel aged beers).

To hit that mark, you have to know your yeast very well, know your brewhouse and cellar very well, and pull from a quiver of tricks and procedures to get the beer to finish exactly where you want it.
Getting your starting gravity where you want it is easy. Working with the yeast to get your finishing gravity right is more difficult. Come in too low, and you get a thin, dry body. Too high, and you get a sticky, worty mess.

Brewing good high gravity beers requires good technique, skill, and a lot of trial and error. Frankly, many breweries are just not there yet...

 

If they only had training . . .

 

Crazy