[AmandaK]

Please keep this discussion on topic and respectful.

I wanted to find out for myself if there is a perceptible difference between 150F and 145/158F. On my system, I dough in for every batch and mashout for every batch. The only variable here is the time and temperature rests in between. I just want to be able to prove to myself, once and for all, that there is a discernible difference between these two techniques. I fully expect them to be similar, how similar is the question for me.

The Zymatic ramps at 1.9*F per minute, so I determined that I should eliminate as many variables as possible, which meant keeping the dough in and mashout for both beers. Had I done one with and one without, that would be another variable, so I wouldn't only be testing 145/158 versus 150.

Here's most of the original post:

Now that we have a Zymatic and can perform very precise measurements/procedures, I'm giving a real comparison a shot. I've brewed two identical German Pilsners using these two mashing techniques, taking readings at nearly every chance I could. I dumped the logged data out, overlaid the gravity readings, and now I'm sharing.

Recipe, for each brew day:
German Pils - based on Wort HOG's recipe
Batch size: 2.5g
OG: 1.053
FG (anticipated): 1.012
IBU: 53
SRM: 5
-------------------------
5.5 lbs Best Pilsner
4 oz Carapils
4 oz Melanoidin
-------------------------
Bru'n Water: Yellow Dry
Ca 40, Mg 8, Na 8, SO4 91, Cl 29
-------------------------
60' - Herkules - 15.8% - 0.35 oz
15' - Vanguard - 4.8% - 0.75 oz
15' - Saaz - 3.5% - 0.5 oz
-------------------------
WY2206, 2L starter in 5L flask. Shaken, not stirred. Pitched at high krausen.

Beer #1 (150F):
Mash times/temps: 104F dough-in for 10', 150F sacc rest for 80', 175F mash out for 10'
Target mash pH: 5.45
Actual mash pH: 5.47
Pre-boil SG: 1.051
Conversion efficiency: 91%
Target boil pH: 5.0-5.1
Adjusted pH in 'kettle' to 5.01, 1.8mL 88% lactic
Post-boil SG: 1.053
Fast-ferment test (w/ bread yeast, expected to be 0.2 Brix high): 1.013



Beer #2 (145/158F):
Mash times/temps: 104F dough-in for 10', 145F beta rest for 40', 158F alpha rest for 20', 175F mash out for 10'
Target mash pH: 5.45
Actual mash pH: 5.47
Pre-boil SG: 1.051
Conversion efficiency: 91%
Target boil pH: 5.0-5.1
Adjusted pH in 'kettle' to 5.01, 1.8mL 88% lactic
Post-boil SG: 1.053
Fast-ferment test (w/ bread yeast, expected to be 0.2 Brix high): 1.013



Full data set here.

Several interesting observations:

• There is a huge difference in speed of conversion between 145F and 150F. The 150F mash converted in about 30' while the 145F mash never got to the same conversion in the 40' and only reached that same conversion during the 158F rest. I thought it would be slower, but I didn't think it would be that much slower.
• Each batch had EXACTLY the same gravity. The Z is basically a fully recirculating "brew in a bin" HERMS, I'm not sure if that has something to do with all of this, but it should be said.
• I'm also surprised at the work the mashout did on increasing the gravity. Here, it increased the SG by 17%. This is similar to what I've seen for other batches on the Z (+16-17%) for the mashout.
• The fast-ferment test indicated exactly the same FG for these batches, which also goes against what I've thought in the past. (More malt flavor, more fermentability.)

Some pictures:
Actual brew day, for the uninitiated:


The fast ferment test all set up:


Right after pitching the Hochkurz one (pitched the 150F about 12 hours ahead of time, since that was brewed in the morning and the other in the evening):


These have been rocking since 11/22/2015, and I'm about to take my first gravity readings and samples tonight. Pitched at 48F, fermented until 11/29 at 50F, now at 56F.

Gravity reading on 12/1 was 1.021 for both batches.

I tasted both of them, which of course I am biased, but this is preliminary at best. They have the same aroma as far as I can tell. The flavor is where it seems different, but they are very similar. The Hochkurz is more pronounced graham cracker, a touch of honey, and a light hint of graininess. The 150F, while very similar, is more grainy, similar honey notes, but less graham cracker. Mouthfeel is the same.

I had these out when Myles came home and asked what the difference was. He is also aware of the nature of this experiment but did not know which was which. He spent a while on the aroma, but immediately picked out the flavor of the Hochkurz to be more rounded.

Will this perceived difference hold up in the end? Not sure, but I'm looking forward to finding out.

On 12/3, I ramped them up to 62F. They will remain there until they are completely fermented.
 

[RPIScotty]

I've had good results on Belgian brews using 132/148/156 in the past. I have been trying to decrease my mash times towards dmtaylor's 40 minute mark and the Hochkurz might be worth trying.

I'm trying to limit the infusions because I use such a small mash tun. Doing the steps typically throws my water to grist out of whack because I have to cut it way down for the initial infusion (< 1 qt/lb).


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[Stevie]

Derek, how is dough in at the first rest? I have been wanting to try a ~130° dough in for beers that max out my mash tun. According to Kai, the lower temp prevents dough balls so I figured I could dough in low, mix as well as I can without fear of splashing over the side, and add my sacc rest infusion to max out my tun.

[RPIScotty]

It works pretty well. I've had to worry very little about dough balls for nearly all of my brews but especially since using the lower rest.


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[Stevie]

Cool. I never have much trouble with normal beers, but big max capacity beers are such a PIA to stir.

Amanda, is low dough in infusion with your new Z based around the same logic?

[AmandaK]

Amanda, is low dough in infusion with your new Z based around the same logic?

Yes.

When I bought the Sabco, the previous owner (John Fowler, the master judge in KC before I ranked up and he moved away), told me that he did a dough in based on what George Fix had stated in Principles of Brewing Science. Basically the grain more readily accepts moisture at a lower temperature, around 104F or so, then it does at typical mash temperatures which leads to better conversion efficiency.

PicoBrew uses that same logic in their "high efficiency" mash program (104/152/153/175), but I find their software to be...well... lacking - at best. I have never hit the OG that their software "predicts" and it's consistently off by a certain %. Anyway, long story made short is that without the dough in at 104F (and mashout at 175F) I get about 79% conversion efficiency. With the dough in and mash out, I get consistently 91% conversion efficiency. I do not know if that it from only the mashout or if the dough in actually does something, but I doubt I'll test that.

Once I do about 10 or so more beers on the Z, I'll write up a proper review. Maybe by then they will have their long promised "new software" released by then. 

[AmandaK]

I'm trying to limit the infusions because I use such a small mash tun. Doing the steps typically throws my water to grist out of whack because I have to cut it way down for the initial infusion (< 1 qt/lb).

Would a heat stick work in your situation? That's how I used to step mash in a cooler.

[RPIScotty]

I'm trying to limit the infusions because I use such a small mash tun. Doing the steps typically throws my water to grist out of whack because I have to cut it way down for the initial infusion (< 1 qt/lb).

Would a heat stick work in your situation? That's how I used to step mash in a cooler.

I thought about that but I'm drawing up the plans for my 1.5 gal electric system with electric HLT and BK plus cooler MLT.

I've got a 1 week old and a 2 year old currently and once we get our routine back together I'll be sourcing some parts. I might go bigger (2.5 gal batches with 5 gal MLT) to better facilitate Parti-Gyle sessions.

Is the Z programmable? It would be great to manipulate the software.


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[AmandaK]

Is the Z programmable? It would be great to manipulate the software.

I'll PM you so as not to derail any further. 

[mchrispen]

When I bought the Sabco, the previous owner (John Fowler, the master judge in KC before I ranked up and he moved away), told me that he did a dough in based on what George Fix had stated in Principles of Brewing Science. Basically the grain more readily accepts moisture at a lower temperature, around 104F or so, then it does at typical mash temperatures which leads to better conversion efficiency.

Hi Amanda,

Did he rest there or ramp directly into the first rest? I have had good luck grain in at 148F for a 45-60 minute rest, then up to 159/160F. And always get that extra 5% or so extract efficiency... my last pils grained in at 130F for 10 minute rest, fast ramp to 148 for 45 and up to 160 for 20 and a mash out. I am seeing some head retention issues (maybe? might be bias) in this batch, and a touch thinner body.

I really need to brew a side by side version to compare infusion vs step mash with the Sabco.

[AmandaK]

When I bought the Sabco, the previous owner (John Fowler, the master judge in KC before I ranked up and he moved away), told me that he did a dough in based on what George Fix had stated in Principles of Brewing Science. Basically the grain more readily accepts moisture at a lower temperature, around 104F or so, then it does at typical mash temperatures which leads to better conversion efficiency.

Hi Amanda,

Did he rest there or ramp directly into the first rest? I have had good luck grain in at 148F for a 45-60 minute rest, then up to 159/160F. And always get that extra 5% or so extract efficiency... my last pils grained in at 130F for 10 minute rest, fast ramp to 148 for 45 and up to 160 for 20 and a mash out. I am seeing some head retention issues (maybe? might be bias) in this batch, and a touch thinner body.

I really need to brew a side by side version to compare infusion vs step mash with the Sabco.

It has been many beers since that brew day and I no longer remember. He is on here, let's see if he can remember for me. @jcfowler? You there?

[brewinhard]

Yay!  Sharing of knowledge is back on the table! 

[RPIScotty]

Yay!  Sharing of knowledge is back on the table! 

Tread lightly my friend. The goal is to leave the old thread behind.


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[dmtaylor]

Where's the Like button? 

Looking forward to hearing more results from this line of experimentation.

[chezteth]

Out of curiosity how long does it take to ramp from one temp to another on the Zymatic?

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