Mash times revisited

[Nightshade]

Been doing some reading (mostly on here) about mash times and how it effects attenuation and want to open a renewed discussion about the effects of short vs long mash times.

So here is my anecdotal evidence based on a brew I did the other day.

Hefe (standard procedure)
Avg SG - 1.050
FG - 1.010
Mash temp - 155
Mash time - 45 minutes
Fly Sparge

Hefe (test procedure)
SG - 1.056
FG - still fermenting
Mash temp - 155
Mash time - 90 minutes
Fly sparge

Ok so the question this poses is, did the extended mash time cause the jump in gravity?

Mash time is the only variable that changed in the process (I brew this every other week), grains, temps, boil etc. all ritualistically the same. In the years I have been brewing this recipe I have never had it hit an SG of of over 1.050-1.052

I will know the FG in a few days and report that as well. All the threads and responses I saw were dealing with the attenuation but mention nothing of an increased extraction rate.

If anyone has any insight on this I would appreciate some feedback.

 

[JimRausch]

Interesting. And unless it's a random change(seems doubtful), considering your only variable was the longer mashtime, it has to be that. Do you routinely do an iodine test?

 

[Nightshade]

Interesting. And unless it's a random change(seems doubtful), considering your only variable was the longer mashtime, it has to be that. Do you routinely do an iodine test?

No iodine test, might have to look into getting some test strips in here to take a look at that as a variable. The place I brew has never done them and just gone off of time in tun.

 

[beersk]

I actually have not seen an increase in attenuation based on increase in mash times. I must be doing something wrong. If this is the only variable that changed, it's likely because the grains had more time to convert starches to sugars. Or maybe it's a different crop of malt...

 

[JimRausch]

Further thinking about what might happen during a longer mashtime:
Did the 155 stay steady, or could it have dropped down into the 140's? Perhaps the increased time would increase shorter chain, more fermentable sugars from the dextrins formed at 155?
It will be interesting to see what your FG turns out, as well as drinking qualities.

 

[Nightshade]

Further thinking about what might happen during a longer mashtime:
Did the 155 stay steady, or could it have dropped down into the 140's? Perhaps the increased time would increase shorter chain, more fermentable sugars from the dextrins formed at 155?
It will be interesting to see what your FG turns out, as well as drinking qualities.

According to the temp readout it remained at 155 the entire time, it is a commercial system and holds temp very well.

 

[JimRausch]

For the iodine test, I just use some betadine picked up at a drugstore. A couple drops of wort on a white paper towel and a drop of betadine.
But, while it shows starch of course, I'm thinking I read something where dextrin-length chains won't react, along with simple sugars of course. I'll have to see if I can find that again.....

 

[Setesh]

That's interesting. I know that longer mashes will generally yield higher fermentability, but I wasn't aware it would yield higher gravity. Were the fly sparge times identical? A slower fly sparge can have a large affect on yield. In other words, if batch A was sparged in 52 minutes and batch B took 62 then I would expect batch B to have a higher SG.

 

[Nightshade]

That's interesting. I know that longer mashes will generally yield higher fermentability, but I wasn't aware it would yield higher gravity. Were the fly sparge times identical? A slower fly sparge can have a large affect on yield.

Sparge times were pretty close in time I would say +/- 10 mins which is an average variance for me.

 

[Setesh]

Sparge times were pretty close in time I would say +/- 10 mins which is an average variance for me.

I wonder if that would be enough for that result?
A 10 minute difference from 52 minutes to 62 minutes is a 16% difference in the amount of time, which also means a 16% difference in flow rate. It seems possible to me that could explain at least some of the difference in yield. My logic is that the slower the rinsing is done the more diffusion of sugars takes place, making your final SG greater.

Another theory is that if the viscosity of the wort is lowered by the extended mash time it would have the same effect as a slower sparge since the more viscous a medium is the slower diffusion takes place.

Maybe a little from column A and a little from column B?

 

[Nightshade]

So beer finished fermenting and stopped at 1.010 which is no different than normal.