19 replies to this topic

[3rd party JKor]

I've been wanting to do some controlled mash experiments for quite a while.  Well, I haven't been brewing regularly since 2011, so it hasn't made much sense to work on this.  Now that I'm back in the saddle (mash tun?), it's time to start.  

 

The first experiment idea came from Union Jack thread in the recipe forum.  Firestone Walker is said to use a step mash to get higher fermentability in their IPA.  I used a 145x45-158x30 mash schedule for my Union Jack clone (still fermenting).  In the thread there was some commentary from people who have used similar step mashes but had not really noticed much difference.  HERMSman posted that he had attenuated a high gravity IPA from 1.080(?) down to below 1.010 using the stepped method.  Having used this step mash method for the first time it was a natural start for my mashing experimentation.

 

Of course, this is also a common method in German brewing, referred to as a Hochkurz mash (see bottom of Kai's page on infusion mashing).  Again, supposedly done to increase wort fermentability.

 

I'm going to complete two mashes, one stepped, one single infusion.  Single batch sparge.  The malt bill is just 2 row pale, 1.3 qt/lb.  I'm going to record refractometer readings throughout the mashes, first wort gravity, pre-boil grav (planned 15 min boil).  The worts will be force fermented using dry bread yeast in order to determine the limit of attenuation of each wort.  Ultimately the idea is to see if there is any difference in first wort gravity, OG and limit of attenuation between the two worts.  If there are any additional ideas on information to collect, I'm open to suggestions.

[denny]

Good on ya!  If you feel like taking the time, we'd love to have your results on www.experimentalbrew.com

[SchwanzBrewer]

Why dry bread yeast?

[HVB]

Why dry bread yeast?

https://www.brews-br...5158/?p=2099207

 

He has it and no time to get other yeast.

[3rd party JKor]

Why dry bread yeast?

Yeast strain has minimal effect on limit of attenuation. It's also a comparative test, so absolute attenuation numbers aren't important to the result.

[3rd party JKor]

Good on ya!  If you feel like taking the time, we'd love to have your results on www.experimentalbrew.com

 

 

Sure, should I post them up on the forum?  Kinda slow over there, man!

[neddles]

Sounds like your set on using bread yeast but if these were more "normal" beers (with hops and regular yeast and the like) you might get a more valid taste eval from the experiment.

 

BTW, what yeast did you use for the UJ?.

Edited by nettles, 19 August 2015 - 12:40 PM.

[denny]

Sure, should I post them up on the forum?  Kinda slow over there, man!

 

Yes, it is...we're so intent on getting the new book done we've been neglecting that site.  But yeah, put it in the forum.

[3rd party JKor]

Sounds like your set on using bread yeast but if these were more "normal" beers (with hops and regular yeast and the like) you might get a more valid taste eval from the experiment.

 

BTW, what yeast did you use for the UJ?.

 

 

I'm not sure the forced ferment test would yield useful tasting results regardless of strain used.  I'll save that for the yeast experiment series...

 

WLP002 for the Union Jack.

[3rd party JKor]

Preliminary results.

 

The 145/158 converted a more completely and ended up with a bit higher OG.  1.043 for the 152 mash, 1.046 for the 145/158 mash.  Virtually identical volumes.  0.41 gal for the 152, 0.42 gal for the 145/158.

 

updates to follow...

[Brauer]

I'm not sure the forced ferment test would yield useful tasting results regardless of strain used.

Yeah, I wouldn't expect either to taste very good. I think if you could eak out an estimate of perceived dryness and body, it would be useful information. Did you adjust them to the same OG?

When I've done experiments like this, in the past, I've done a variation on a triangle test, to adjust for bias. By tasting three glasses, taking three sets of notes, and seeing if the two identical beers got the same evaluation.

When there wasn't anyone around to pour 3 glasses behind my back, I've done this by marking the bottom of 4 taster glasses, pouring 2 of each beer, then mixing them up like 3-Card Monte, until I couldn't remember which was which, and pulling 3 random glasses.

[3rd party JKor]

Yeah, I wouldn't expect either to taste very good. I think if you could eak out an estimate of perceived dryness and body, it would be useful information. Did you adjust them to the same OG?

When I've done experiments like this, in the past, I've done a variation on a triangle test, to adjust for bias. By tasting three glasses, taking three sets of notes, and seeing if the two identical beers got the same evaluation.

When there wasn't anyone around to pour 3 glasses behind my back, I've done this by marking the bottom of 4 taster glasses, pouring 2 of each beer, then mixing them up like 3-Card Monte, until I couldn't remember which was which, and pulling 3 random glasses.

 

Yes, I think there will be some validity to the tasting results, even if they don't taste 'good'.  As time goes by I'll continue to run these small sample tests with varying yeast, hops, grains, mash schedules, etc., etc.  THis is just the first of many.

 

I didn't bother to adjust OG.  I didn't think they were far enough apart for it to be a major factor in the limit of attenuation numbers.  Of course, the fact that I didn't take the time to normalize them almost guarantees the results will be nearly identical, so I have to wonder whether I should have normalized the gravity.  

 

The nice thing about your tasting method is that, nowadays, I'll forget which one is which by the time I put all the glasses on the counter!

[3rd party JKor]

Here are the Brix vs. time profiles for the three mashes I did.  

 

Mash #1 was a bit of a screw up, I was still learning the equipment and getting much more fluctuation than I would have liked.  I also don't believe I was getting accurate temp readings.  Ironically, it had the highest first wort gravity.  Ultimately, I think it nded up as a step mash with the first step in the upper 140s for 30min and the second step in the low- to mid-150s for 30 min.

 

Wort #2 is the 152x60 wort and wort 3 is the step mash which ended up more like 145x40, 160x30.

 

I think it's really interesting to see the initial stages of the mash, especially between mash 1 and 3.  They show a pretty clear denaturation of beta amylase, with wort 1 dying out around 25 minutes (average wort temp around 147-148) and wort 3 looking like it hit a wall around 40 minutes (144-145 mash temp).  They both got to 15 Brix but the 148 mash did so much quicker.

 

Wort 2 had the typical mid-range single infusion mash profile.  It jumped out quickly but lost steam versus the step mashes when they bumped into alpha activity range.

 

It's interesting to note that none of these mashes came close to theoretical first wort gravity, which should be 22.1.  the worts had conversion efficiencies of 91%, 85% and 81%, respectively.   Wort 1 wasn't far off, but still not what I'd consider 'good' conversion.  A little surprising that the mashes had such trouble converting.  I'm wondering about the diastatic power of this 4 year old pale ale malt, now.

 

[denny]

Damn...cool stuff!  Thanks!

[neddles]

I think your experiment and data are really cool and I expect to get something from it. So thank you. I do wonder though if you'd have been better off using fresh malt like you suggested. Like you said it seems conversion efficiency should have been better.

[3rd party JKor]

I think your experiment and data are really cool and I expect to get something from it. So thank you. I do wonder though if you'd have been better off using fresh malt like you suggested. Like you said it seems conversion efficiency should have been better.

 

 

I pretty much only have old grain right now, or I would've used new grain.  I have a bunch of new grain on order though, so I will use that in the future.

[Brauer]

It's interesting to note that none of these mashes came close to theoretical first wort gravity, which should be 22.1.  the worts had conversion efficiencies of 91%, 85% and 81%, respectively.   Wort 1 wasn't far off, but still not what I'd consider 'good' conversion.  A little surprising that the mashes had such trouble converting.  I'm wondering about the diastatic power of this 4 year old pale ale malt, now.

If the old malt has absorbed a lot of moisture in the current humidity, it may have lower potential extract due to a higher percentage of the weight being water. Noonan said that 2% additional moisture would decrease potential yield by 4%, but I can't figure out why it wouldn't decrease by 2%.

[3rd party JKor]

The worts were vigorously fermenting away when I got home yesterday.  I was shaking them every few hours, then at about 11 when I checked them they were dead still.  I've continued to shake them but they're likely done.  I'll be checking gravities tonight.

 

 

If the old malt has absorbed a lot of moisture in the current humidity, it may have lower potential extract due to a higher percentage of the weight being water. Noonan said that 2% additional moisture would decrease potential yield by 4%, but I can't figure out why it wouldn't decrease by 2%.

 

 

Yes, that's certainly a possibility.  I should probably do a quick moisture content check.

Edited by JKor, 21 August 2015 - 06:58 AM.

[positiveContact]

Yes, that's certainly a possibility.  I should probably do a quick moisture content check.

 

how do you do that?  compare volume and weight of new grain vs old?

[3rd party JKor]

how do you do that?  compare volume and weight of new grain vs old?

 

 

Weigh it then dry it in the oven.