Effect of various mash temperature, sugar, enzyme combination on beer flavour.

[Cloud Surfer]

When I make beer, I always target an FG for the style. The tools I use are mash temperature, sugars and enzymes/glucoamylase to achieve the desired FG. Let’s pick an FG of 1.015 for example. I can mash at a higher temperature and include some sugar in the recipe. Or, I can mash at a higher temperature and use glucoamylase in the mash. Or, I can mash at a lower temperature and use neither of these.

Here’s my question I’m trying to get my head around. If I make these 3 beers as described and they all achieve an FG of 1.015, have I made identical beers that will taste the same?

My thinking is I have created the same/similar sugars in the wort using the 3 different techniques, because the yeast have arrived at the same FG of 1.015 in each beer. But will the beers taste the same?

 

[Jeroen79]

No it will taste different, you will get more or less complex sugars which are harder for yeast to ferment, so you can get a beer that taste sweeter or dryer.

 

[Cloud Surfer]

No it will taste different, you will get more or less complex sugars which are harder for yeast to ferment, so you can get a beer that taste sweeter or dryer.

Using your example, if I make a wort with more complex sugar, I agree it will be less fermentable and the FG will finish higher, so the beer will taste different. What I’m saying is I can make 3 different worts that finish at identical FG.

I can use a higher mash temp for more complex sugar and then add simple sugars, or use a higher mash temp for more complex sugar and then add glucoamylase to increase the simple sugars, or mash at a lower temperature to get a balance of complex and simple sugars. So all 3 worts are identically fermentable, because I can get them all to finish at 1.015. So I am guessing/questioning that they all have the same balance of complex and simple sugars, and therefore will the finished beer taste the same?

 

[Jeroen79]

Well yeast do also ferment complex sugars, but to a lower extent, unless you have a Diastatic yeast?

But why not just test it an do 3 ferments at the same time, it is the only way to really know?

 

[corncob]

I have nothing substantial to back this up, but I firmly believe that a sweeter tasting beer is produced by mashing low, for fermentability, and using a lower-attenuating yeast. In that case, the remaining sugar profile seems (to me) to be more sensibly sweet to the human palette, than when mashing high, for body, and pitching a high attenuating yeast, even though the og and fg of both might be the same.

People often use "sweet" and "dry" as opposites. Maybe that comes from the world of wine--I don't know. But my perception, based on my brewing experience, sees "sweet" on a different axis. There are sweet and thick beers. There are sweet and dry beers. (I much prefer to drink the latter). There are thick beers that aren't very sweet--many stouts and the malty German styles strike me this way.

I also think yeast selection plays a huge role in these perceptions for reasons other than attenuation, as well. I believe that a lot of ale yeasts will leave way more body at a given attenuation than most lager yeasts, for example (glycerol, maybe?).

This is a great subject for thought and discussion, especially considering the huge variation in how people taste.

 

[G_robertus]

I think you'll get three entirely different products. Glucoamylase is probably also not an option here as it tends to dry out beers completely. But the main point is that you get different residual sugar and nutrients balances which will change the outcome. I don't think any of them would have the same balance of complex/long chain sugars which will cause them to taste different.

Mashing high and adding sugars will indeed give a lot of complex sugars which give flavour. Using simple sugars also means that you add more carbon than nitrogen, so the alcohol and ester profile will be different compared to an all malt grain bill. I can also imagine that using standard sugars in your house compared to mainly maltose from grains can trigger slightly different metabolic pathways which will have a different effect down the line, but I'd have to look that up (and maybe correct for the nutrient discrepancy). Mashing lower and not adding sugars will give you a more balanced carbon and nitrogen mixture. I would say this would be close to using extra enzymes (just not glucoamylase), but the differences in mash temperatures could maybe lead to different end products. Temperature also affects how well other molecules are dissolved and what reactions take place and at what speed. Apart from that, depending on the enzyme the bonds of complex sugars and starches that are broken could be different to those that are broken using just malt resulting in a different end product. Yeast would probably also play a role here, because if you end at 1.015 with a lot of maltotriose it would probably taste very different from a beer that gets there on longer dextrins.

 

[dmtaylor]

You will get three different beers, because the chemistry is different. Fermentation involves a very complex series of hundreds of different kinds of chemical reactions, and results in thousands of flavor compounds at varying taste thresholds. It is likely you will have three similar beers, but should be able to perceive subtle or even more obvious differences in the taste of the finished product.

In your example, I would hypothesize:

The first with added sugar is likely to taste stronger or more dilute, depending what sugar you use and how much. If you are substituting malt for a simpler sugar to hit the same gravity numbers, this typically will tend to dilute the perception of malt flavor, albeit very slightly unless you use a large quantity of adjunct.

The second with additional glucoamylase might turn out OK but it is also very difficult to control what that enzyme does in your mash based on the amount used and exact temperatures in different places within the mash. I would expect this beer to taste more dry than the third unadulterated "control" beer... but maybe it wouldn't. Too many variables to say for sure.

And in the third beer, the lower mash temperature might result in better or worse efficiency, with a higher or lower original gravity, or might require more or less weight of grist to match the OG and ABV of the other two beers. Any changes in any of these parameters likely has some minimal impact on finished beer flavor, though I admit I would expect this effect to be extremely minimal and perhaps inperceptible to the human palate.

So.... while the flavor differences might range from barely perceptable to vastly different between the examples.... I do believe many people (not all but many) would be likely to be able to detect differences in a blind tasting. And as @Jeroen79 alluded to above, the only way to know for certain is to run multiple blind triangle tests. Not just one, but many many.

 

[Cloud Surfer]

Thanks guys for the input. I won a beer comp and subsequently got to brew 1200 litres of one of my beers at a brewery. One of the things I learned about on the day was glucoamylase that the pro used. So I’ve used it several times now in the mash. It’s pretty easy to use and control after a bit of trial and error. But I do perceive a slight loss of malt character, and was wondering if it was my imagination, hence I thought I would ask the question.

 

[InspectorJon]

I can use a higher mash temp for more complex sugar and then add simple sugars,

If you use the same grain bill, mash high and add sugar I think you will end up with more alcohol but not a lower gravity. Simple sugar will boost alcohol but doesn’t significantly reduce FG.

If you added enough simple sugar to produce enough alcohol to counter balance the remaining complex sugars and finish with a low gravity you would have a very strong beer and that would definitely be different. At least that’s how it seems to me.

 

[Jeroen79]

You should not really need glucoamylase either unless you have very special malt that hasn't got enough enzymes.

 

[dmtaylor]

Sounds like that commercial brewery that always uses enzyme was burned once a few years ago and now uses the enzyme as an insurance policy. I suppose once they understand it well enough to have it completely dialed in, they can make great beer with it. The rest of us... don't need it.

 

[mac_1103]

Glucoamylase in the fermenter is impossible to control. Glucoamylase in the mash can be controlled with time and temperature, just like pretty much everything else in the mash.

 

[Halfakneecap]

Thanks guys for the input. I won a beer comp and subsequently got to brew 1200 litres of one of my beers at a brewery. One of the things I learned about on the day was glucoamylase that the pro used. So I’ve used it several times now in the mash. It’s pretty easy to use and control after a bit of trial and error. But I do perceive a slight loss of malt character, and was wondering if it was my imagination, hence I thought I would ask the question.

What benefit do you get out of it?
Is it just a low FG? I rarely end up with a FG of 1.010 or above.