High Attenuation Question

[StarsanManiac]

I’d like to figure out why my first 2 batches are so highly attenuating. I got 1.056 to 1.010 on 2-row SMaSH, split batch using both Notty and US-05. Then I got 1.058 to 1.007 on a Vienna SMaSH using US-05. Using my recently built herms I attempted the following 40-60-70 schedule with minor variations between both batches.

15L (16 qt) at 44C (111F) into 9kg (20 lb) grain. Mix and stir to get rid of dry spots. Takes about 15 minutes, mash measures 40C (104F)
Boiling infusion of 12L (13 qt), measured 60C (140F) after stirring.
After 10 more minutes start recirculating ramp to 70C (158F). Ramp was slow, took most of an hour.
Mash out to 75C (167F) after conversion test complete, about 70 min after the boiling infusion.

I don’t really need the protein rest but it seemed like a good way to get everything mixed up before going to mash temperature. More confusing for me is that the Vienna SMaSH hit 63C(145F) after the boiling infusion and my ramp to 70C (158F) was faster, but it ended up attenuating even further. Does conversion start during a protein rest at 40C (104F)?

 

[tehnick]

Sounds like the mash was highly fermentable from the 60C infusion temp. The slow ramp to saccarification (sp) most likely kept the temperature in the 146-151 range for a while and that will lead to drier, more attenuated beers, especially with a yeast strain that can hit 12% abv when working right.

 

[dobe12]

The rest in the 140's is the reason. If you are looking for a higher final gravity, you want to mash in the low to mid 150's.

 

[StarsanManiac]

Ok. I was under the impression that the beta amylase took longer to do their job. I was probably under 66C (151F) for 30 to 40 mins. If I ramp faster from 60C (140F) would that help, or should I just infuse to 66C (151F) and start the ramp to 70C (158F) right away? Then if I want to back off of the body/maltiness on the next batch I could infuse slightly lower. Or better to hold at 66C (151F) for a bit longer?

I’m drinking the 2-row SMaSH now (made with Weyermann 2 –row pale, Willamette) and it cleared nicely without any fining and has great head retention, it just has about 1.5% more ABV than I was intending. It still finishes a bit sweet, which I don’t understand.

For the protein rest, is it fair to say that I could leave it at 40C (140F) indefinitely without conversion?

 

[tehnick]

This weekend I'm brewing a dunkelweizen. I'll be mashing at 126 for a protein rest for 30 min, then decocting and adding back to the mash to hit about 154 where it will stay for about 45 min. I'll then drain the tun, add my sparge in at 175-180, seal the cooler for 10 min, vorlauf, and drain to boil. Those few steps will help me hit the desired body mainly because the temps will hit in a fairly quick amount of time. Conversion can happen in as little as 15 minutes so if you're ramping slowly, by the time you hit mash out you would have mashed the majority of the time at low temps causing more fermentable sugars. 140-158 over an hour ramp leaves the mash in the 140-152 range for the majority of the conversion.

 

[RM-MN]

You are correct in believing that the beta amylase takes longer to convert but finding info on just how much longer is hard to do. I've done some testing with grains that are milled very fine for my BIAB system and wanted to know how long conversion would take. I used iodine to test for starch with the idea that when conversion was done there would be no starch left. For my experiment I planned to take a sample when the grains were just added and every 5 minutes until the iodine showed no change. My first sample turned the iodine dark purple or dark blue indicating there was starch which there should be when the grains were first added. My second sample was at 7 minutes because I got distracted and missed the 5 minute mark but at 7 minutes the iodine wouldn't change color at all. Yes, that fast.

For most mashes it would take longer because the grains are milled coarser and it takes more time for them to get wet through and conversion can't happen until they are wet. In your case, your grains had time to wet through when you did the protein rest so when you finally brought them to the sacrification temperature they quickly converted and the beta amylase had plenty of time as you slowly ramped the temperature up. With the modern, well modified malts, you probably won't gain anything by ramping the temperature up as the two amylases will work too quickly for your temperature change to have much effect. I'd suggest you start with temperature about 152 to 154 and don't even try ramping it up.

The enzymes have a preferred temperature range but I wouldn't be too sure that beta amylase wouldn't have any conversion at 140 F. I think you can get a protein rest at a lower temperature though. Plamer states that this happens between 113 and 131 F.

 

[RM-MN]

This weekend I'm brewing a dunkelweizen. I'll be mashing at 126 for a protein rest for 30 min, then decocting and adding back to the mash to hit about 154 where it will stay for about 45 min. I'll then drain the tun, add my sparge in at 175-180, seal the cooler for 10 min, vorlauf, and drain to boil. Those few steps will help me hit the desired body mainly because the temps will hit in a fairly quick amount of time. Conversion can happen in as little as 15 minutes so if you're ramping slowly, by the time you hit mash out you would have mashed the majority of the time at low temps causing more fermentable sugars. 140-158 over an hour ramp leaves the mash in the 140-152 range for the majority of the conversion.

From my testing, conversion can happen in as little as 2 minutes.

 

[StarsanManiac]

This is very interesting and just the kind of detail I'm looking for. Thanks!

The enzymes have a preferred temperature range but I wouldn't be too sure that beta amylase wouldn't have any conversion at 140 F. I think you can get a protein rest at a lower temperature though. Plamer states that this happens between 113 and 131 F.

I did my protein rest at 104F, not 140F. Is the 113 to 131 a better range, i.e. 126F as the other poster did?

 

[RM-MN]

This is very interesting and just the kind of detail I'm looking for. Thanks!



I did my protein rest at 104F, not 140F. Is the 113 to 131 a better range, i.e. 126F as the other poster did?

I'm quoting John Palmer from his book, "How to Brew" where he states that a beta glucan rest would be between 98 and 113 F. That puts your rest at 104 right in the middle of beta glucan which breaks down the sticky parts of wheat or rye that otherwise would surely give you a stuck sparge. 126 F. would be in the middle of the protein rest.

 

[Yooper]

This is very interesting and just the kind of detail I'm looking for. Thanks!



I did my protein rest at 104F, not 140F. Is the 113 to 131 a better range, i.e. 126F as the other poster did?

Why are you doing a multi-step infusion starting with a beta glucans rest? If you are using a ton of adjuncts or something, that's ok but if you're doing a mash with well modified malt, you aren't gaining anything (and in fact seem to be losing somethings that you want, like a higher FG and more body in the beer).

I'd stop with the step mashing unless you know absolutely what it is that it accomplishes, and why.

Try a single infusion mash at 152. Don't ramp or anything- just hold it there for the full mash time. After that you can ramp to mashout temperatures if you want, and then sparge.

 

[StarsanManiac]

Why are you doing a multi-step infusion starting with a beta glucans rest?

Admittedly I have confused beta glucan with protein rest, AND I'm not fully aware of the benefits/trade-offs of the various rests. I skimmed Palmer a while back and decided to try the 40-60-70 step mash (104 - 140 - 158°F)

http://www.howtobrew.com/section3/chapter16-2.html

I built an electric herms system because I could. Then, I did step mash because I could. From what I'm hearing a single infusion would give me the beer I want more so than the 40-60-70, but given my setup I don't find step mashes any more of a challenge. Do the fully modified malts I'm using benefit AT ALL from beta glucan or protein rests? The beer I'm drinking now is nice and clear with a great head despite being a simple 2-row SMaSH and I would not want to lose those aspects in my next brew.

 

[RM-MN]

Wheat and especially rye benefit from a beta glucan rest as they make a very sticky grain bed. Wheat sometimes gains by using a protein rest but barley probably doesn't at all. Try the single infusion and see if it gets you where you want to be. Remember the step mashes if you work with rye or wheat.

 

[StarsanManiac]

That seems like the right approach. Thanks everyone for the info and suggestions.

 

[tehnick]

This is very interesting and just the kind of detail I'm looking for. Thanks!



I did my protein rest at 104F, not 140F. Is the 113 to 131 a better range, i.e. 126F as the other poster did?

Single infusion is best with most malt these days unless you're shooting for something different in your beers. The only reason I'm doing a decoction with my next batch is because the SRM range is 14-23 for the style and all of the malts I'm using only puts it around 7-8 SRM. The decoction is there so I can stick to the style guidelines and achieve desired color. I do single infusion mashing 99% of the time.

I use a 10g gott cooler for my mash tun so the 126 strike is to compensate for a little heat loss but keep it in range for the rest. My grain bill for that batch is 58% wheat.

 

[kingwood-kid]

The enzymes have a preferred temperature range but I wouldn't be too sure that beta amylase wouldn't have any conversion at 140 F. I think you can get a protein rest at a lower temperature though. Plamer states that this happens between 113 and 131 F.

The amylase isn't there for us to brew beer. It's there for the germinating barley seed to be able to metabolize its starch reserves. Since very few Canadian farm fields reach 150F at planting time, I think it's safe to assume that the enzymes are capable of working at pretty low temparatures, albeit pretty slowly when compared to what we're used to as brewers. Even the amylase in your saliva works pretty quickly at around 90 degrees.