fermentable vs. unfermentable sugars in speciality grains

[Farfaloff]

Hi,

I would like to know if their is a way to estimate/calculate the ratio of fermentables and unfermentables sugars in speciality grains.

For exemple, Palmer wrote that medium crystal (60-75L) yield a max ppg of 34 when mashing and 18 when steeping. Out of these numbers, how much is not fermentable and will contribute to the final gravity of the beer?

That could help to estimate the FG especially for big beer like barleywine !

Thanks and cheers !

 

[cannman]

Beersmith will do this for you.

Plug in your recipe, lets say you use crystal 60, depending on your mash temp, it will calculate the amount of fermentables, unfermentables, and estimate an original gravity and final gravity. Hope this helps!

 

[dmtaylor]

I don't have real data but I'm pretty certain that crystal malt sugars are roughly 60% fermentable to the average common yeast strains, as opposed to a mashed wort being about 75% fermentable. It's in that neighborhood. This only comes into play if you steep but don't mash. If you can add some base malt and do at least a mini-mash (if not all-grain) then the enzymes will act on all the sugars and you'll still end up with about 75% fermentability, so you can pretty much ignore the dextrin thing altogether.

Hope this helps.

 

[Farfaloff]

Thanks for your quick answers!

I bought beersmith, but didn't try it for a recipe yet. I read some thread and saw that some people found that it was not really accurate. I guess I will have to try it on my own!

I don't have real data but I'm pretty certain that crystal malt sugars are roughly 60% fermentable to the average common yeast strains, as opposed to a mashed wort being about 75% fermentable. It's in that neighborhood. This only comes into play if you steep but don't mash. If you can add some base malt and do at least a mini-mash (if not all-grain) then the enzymes will act on all the sugars and you'll still end up with about 75% fermentability, so you can pretty much ignore the dextrin thing altogether.

Hope this helps.

So their is still a lot of fermentables sugars in crystal malt, even with the transformation they undergo. I understand that if the grain is not mashed, the starch cannot be used by the yeast. I'm planning an all-grain beer for my next brew, I'll see what are the results!!

Thanks !

 

[kombat]

So their is still a lot of fermentables sugars in crystal malt, even with the transformation they undergo.

I wouldn't take that as gospel - I'd want some actual scientific cite to be sure. My understanding is that it depends on a) the degree of kilning the malt underwent (i.e., Crystal 10 will contain more residual fermentable sugars than Crystal 120), the potential extract of the original grain, the maltster, etc.. In general, I wouldn't expect to extract more than 10% fermentable sugars from any of my specialty grains.

I understand that if the grain is not mashed, the starch cannot be used by the yeast.

This is not entirely true. First of all, starches can't be fermented by the yeast at all. They must be converted into sugars through either mashing (via enzymes) or kilning (via direct caramelization by heat). However, Crystal malts have already had some/all of their starches converted into sugars (some fermentable, some not) by the kilning process, so even without mashing them, you will extract sugars from them, some of which will be fermentable.

 

[Dee_Lynn]

Discussed and tested by nilo here:

https://www.homebrewtalk.com/showthread.php?t=208361

Dee_Lynn

 

[dmtaylor]

Discussed and tested by nilo here:

https://www.homebrewtalk.com/showthread.php?t=208361

Dee_Lynn

Awesome -- thanks for the link. Looks like my estimate of 60% fermentability was a little off -- it's closer to 40-50% based on the real data. But again, if you mash it with enzymatic malt, then a lot of those unfermentable sugars will be broken down by the additional enzymes to bring it up close to normal fermentability. So, it depends whether you just steep or whether you mash.

:rockin:

 

[Farfaloff]

Thx for the link Dee Lynn, that was a very interesting experiment!

According to Nilo's result, even the crystal 120 still have fermentables sugars. He had 38% of attenuation factor when mashing alone and their is sill starch left in the wort!

So I think that we can say that their is still at least 40 to 50% of fermentables sugars in crystal grains like dmtaylor said.

This experiment is a lot of useful info!

But again, if you mash it with enzymatic malt, then a lot of those unfermentable sugars will be broken down by the additional enzymes to bring it up close to normal fermentability. So, it depends whether you just steep or whether you mash.

:rockin:

I guess that enzyme (amylase alpha and beta) are only affecting starch. So even if I'm mashing the speciality grains, their will be no effect on the taste they should contribute to the beer.
All the other unfermentable sugars will be left as is in the wort.

Am I correct with this assumption?

 

[doug293cz]

...

I guess that enzyme (amylase alpha and beta) are only affecting starch. So even if I'm mashing the speciality grains, their will be no effect on the taste they should contribute to the beer.
All the other unfermentable sugars will be left as is in the wort.

Am I correct with this assumption?

Depends on the exact chemical nature of the unfermentable sugars. Alpha amylase can break down any starch or sugar with alpha 1-4 bonds (all the bonds in amylose, and 93% - 94% of the bonds in amylopectin) until they reach the point of being limit dextrins (alpha 1-6 bonds limiting enzyme access to the alpha 1-4 bonds.) If there are other than alpha 1-4 bonds in the specialty grains, those will not be broken by amylase. Speculation: Kilning may create more alpha 1-6 bonds, which would lead to additional limit dextrin, or other types of bonds.

Brew on

 

[dmtaylor]

Thx for the link Dee Lynn, that was a very interesting experiment!

According to Nilo's result, even the crystal 120 still have fermentables sugars. He had 38% of attenuation factor when mashing alone and their is sill starch left in the wort!

So I think that we can say that their is still at least 40 to 50% of fermentables sugars in crystal grains like dmtaylor said.

This experiment is a lot of useful info!





I guess that enzyme (amylase alpha and beta) are only affecting starch. So even if I'm mashing the speciality grains, their will be no effect on the taste they should contribute to the beer.
All the other unfermentable sugars will be left as is in the wort.

Am I correct with this assumption?

No. Enzymes eat any kind of sugars. Starches are really just complex sugars. Dextrins are someplace in between starches and sugars. Sugars are really just very small simple starches. Enzymes work on ALL of the above.

 

[chickypad]

I'm pretty sure Beersmith and other software just go by a straight percentage attenuation and don't have the sophistication to adjust for the fermentability different specialty malts. For example I just put in a recipe with 10 lbs of C-120 and US-05, it's estimating 1.052 OG and 1.010 FG. That ain't happening in real life.

 

[Yooper]

So their is still a lot of fermentables sugars in crystal malt, even with the transformation they undergo. I understand that if the grain is not mashed, the starch cannot be used by the yeast. I'm planning an all-grain beer for my next brew, I'll see what are the results!!

Thanks !

Think of it this way- crystal malt, by the way it's made, is "pre-mashed" so to speak. It provides fermentable sugars, even in a steep. The way it's processed does convert some of the starch to sugars for us and they are fermentable. Very dark crystal malts may be less fermentable, but overall they don't contribute all that much to a higher FG as they are fermentable overall.