Struggling with poor attenuation after new setup

[Smellyglove]

Hi!

I've recently started brewing on my new setup. I went from a three-kettle HERMS, to a two kettle HERMS no sparge setup.

My first few brews are at bottling-time but my gravity readings makes me wonder..

They are high.

I've re-checked all my temp-probes and they are correct.
Yeast-handling is the same as before.

The two I sampled today are:

Wlp380. Should land on 1.013-1.014 landed on 1.016
US-05. After eight days it's at 1.020. Og was 1.067. It "should" be lower.

Also had another 380 a bit earlier which landed on 1.014, should be 1.012.

So. yeast handling and fermentation control is out of the equation, I'm looking at what happens in a thinner mash when it comes to beta-amylase. As far as I know they work a bit slower. but I'd reckcon 45/60 minutes would be enough before I ramp the HERMS up to 72C for some final alpha action. I have a short hose between the HERMS and mash tun so I don't have to overcompensate temperature in herms by more than maybe 0.2C. So I've taken premature denaturation of the enzymes because of excess heat exposure out of the equation as well.

I also make 14L batches now comparing to 22L before.

Anyone?

 

[mredge73]

The only thing that makes sense to me would be mash temp, as higher mash temp will lead to higher FG.

How do you determine what it "should" be? Is this based on previous examples?
Due to the higher volume on the same system it is conceivable that the mash temp dropped lower on your previous batches done on the 3 vessel system.
Lower the mash temp by 1-3C and see if you get desirable results.

 

[Smellyglove]

I've used the same HERMS-setup for both setups, which were/are calibrated to the specific setup.

My mash is 0.1-0.2C +/- comparing to my target temperature.

Yes, "What it should be" is based on my own empirical previous examples on the three-vessel setup.

 

[jamorgan3777]

Yeast need more than just sugar to grow (and thereby convert your wort). Poor attenuation can be a factor of oxygenation level, mineral levels and lack of other yeast nutrients.

 

[TheMadKing]

I've used the same HERMS-setup for both setups, which were/are calibrated to the specific setup.

My mash is 0.1-0.2C +/- comparing to my target temperature.

Yes, "What it should be" is based on my own empirical previous examples on the three-vessel setup.

Not to beat a dead horse, but can you post your actual mash schedule?

Another place to look might be your ingredients. Are you using higher percentages of crystal malt than before? Are you adding extract anywhere?

Can you describe your yeast handling process? i.e. do you use yeast starters, what is your pitch rate, etc. If you doubled your batch size but didn't adjust your pitch rate properly, that might account for it as well.

For the record, I do BIAB full volume mash, with no sparge and I've never had an attenuation issue. I highly doubt that your water to grain ratio is an issue at all. Also 1.016 when you were expecting 1.014 is pretty good, I doubt there's anything wrong with your process. And I'd give the 1.02 beer some more time, but that isn't an unreasonable FG either.

 

[Smellyglove]

I use pure oxygen, and add yeast nutrients to the wort. Same as before. That's why I've written yeast handling off. Fermentation is exactly as before, yeast handling is exactly as before. Mash regimes are ALMOST as before. Now I've added a 72C step to all my mashes, mash precision temperatures are as before, grist composition is exactly as before, although I've gone from BestMalz/Muntons/Weyermann to Weyermann/castle Malts.

I always set a starter, even if I don't need to bump the cell count numbers, but always to ensure good vitality. The batch size is smaller than before.

The water has changed though. I now use a different source and Bru'nWater, which I didn't before. I don't add MG though, since it comes with sulfates, which I don't like.

I live in norway, the minerals in municipal water sources are almost exactly the same all over the country, soft. I moved 100km north. I don't know if MG is an essential mineral for yeast health (so essential that I need to add it to the water, there is close to 0 MG where I live now), and I don't know the water report from the place I lived in before.

 

[TheMadKing]

I use pure oxygen, and add yeast nutrients to the wort. Same as before. That's why I've written yeast handling off. Fermentation is exactly as before, yeast handling is exactly as before. Mash regimes are ALMOST as before. Now I've added a 72C step to all my mashes, mash precision temperatures are as before, grist composition is exactly as before, although I've gone from BestMalz/Muntons/Weyermann to Weyermann/castle Malts.

I always set a starter, even if I don't need to bump the cell count numbers, but always to ensure good vitality. The batch size is smaller than before.

The water has changed though. I now use a different source and Bru'nWater, which I didn't before. I don't add MG though, since it comes with sulfates, which I don't like.

I live in norway, the minerals in water (lakes and stuff) are almost exactly the same all over the country. I moved 100km north. I don't know if MG is an essential mineral for yeast health, and I don't know the water report from the place I lived in before.

hmm, well the only two new things are the system itself and the water, so my bet is on one of those.

In answer to your Mg question, yes it is essential to yeast health but there is plenty contained in the grain for the yeast, so there is no need to add any.

Honestly, don't think there's anything wrong. I regularly get variations of 2-4 points in my FG, especially on bigger beers. What you're describing seems to be within the realm of variation that is normal for a homebrewing setup.

I realize that professional brewers hit the same FG every time, but the variations in temperature, ingredients, yeast health/age, batch size, all inherent in homebrewing makes it less precise than professionally sized breweries.

As long as your beer tastes right, and like what you are aiming for, I wouldn't worry about it. If you do want to attenuate better, I agree with what mredge said before, just drop your mash temps a few degrees. There could be some variable in your new system that isn't accounted for, and you have to compensate a little.

 

[Smellyglove]

Well. That's sort of why I want to look into enzyme-activity in thinner mashes.

If I have to drop the temperature of the mash by a few degrees I guess I'd also need to mash longer, since then we're talking about 63/64C, which is pretty low for a mash "which should attenuate better" at 65/66c. The beta-amylase works slower down there.

 

[TheMadKing]

Well. That's sort of why I want to look into enzyme-activity in thinner mashes.

If I have to drop the temperature of the mash by a few degrees I guess I'd also need to mash longer, since then we're talking about 63/64C, which is pretty low for a mash "which should attenuate better" at 65/66c. The beta-amylase works slower down there.

65C should produce a very well-attenuating beer. I don't understand the need to vary mash time with mash temperatures though. Effectively, 60 minutes is such an overkill for most standard mash temperatures, you never need to vary it unless you drop your mash temperature to 60C or so. Mash thickness has zero effect on enzyme activity. The only things mash thickness affects are pH and lautering efficiency.

In a mash of 63C, 60 minutes is sufficient for beta amylase activity to cease completely. So a mash of 65C for 60 minutes should also result in a highly fermentable mash.

http://braukaiser.com/wiki/index.php?title=Starch_Conversion

This is an excellent resource for learning more about how the different enzymes work and the mashing process. Kai is a great resource for science based brewing.

 

[Smellyglove]

When you say that mash thickness has zero effect on enzyme activity.. are you sure..?

The thicker the mash, the higher density of sugars enzymes collide into and break down. Thinner mash is the opposite..

 

[TheMadKing]

When you say that mash thickness has zero effect on enzyme activity.. are you sure..?

The thicker the mash, the higher density of sugars enzymes collide into and break down. Thinner mash is the opposite..

"The amylase enzymes are more stable in thicker mashes (Figure 8). Which is especially important to the more heat liable β-amylase and as a result thicker mashes give more fermentable worts than thinner mashes when mashing at high mashing temperatures [Briggs, 2004]. But while thick mashes offer better protection for the enzymes, they also inhibit the enzymatic activity through the reduced availability of free water and the sugars acting as competitive inhibitors [Briggs, 2004]. In addition to that the gelatinization of starch is also slower and happens at higher temperatures in thick mashes and as a result thinner mashes are known to give more fermentable worts at normal mashing temperatures."

-Brukaiser's website

Sorry, after doublechecking myself you are correct that it DOES affect enzyme activity, but in the exact opposite way from what you're thinking. A thinner mash will give you a more fermentable mash for the same temperature because there is more sugar in solution (because of the increased water to grain surface area ratio) for both beta and alpha amylase to work on, and less competition between them.

 

[Smellyglove]

I read that too, Briggs cited at Kai Trosters site.

But, browsing through Kai's site i found some pH stuff. I've used Brun'nWater to hit a target of 5.35 at room temp, as I guess that's where you should measure. I've started using phosforic acid to reach these levels, which I dind't use before. Kai says that optimal pH fro fermentability is 5.4-5.6. I'm a bit lower now.. I know I was higher at my old setup.

In fact, my pH target of 5.35 is not within any optimum anything when I look at his pH-numbers. Funny. I thought I was doing good.

 

[TheMadKing]

I read that too, Briggs cited at Kai Trosters site.

But, browsing through Kai's site i found some pH stuff. I've used Brun'nWater to hit a target of 5.35 at room temp, as I guess that's where you should measure. I've started using phosforic acid to reach these levels, which I dind't use before. Kai says that optimal pH fro fermentability is 5.4-5.6. I'm a bit lower now.. I know I was higher at my old setup.

In fact, my pH target of 5.35 is not within any optimum anything when I look at his pH-numbers. Funny. I thought I was doing good.

pH does certainly affect enzyme activity but the effect is minimal compared to temperature and duration. You should be absolutely fine at 5.35, I target 5.4 which is optimal according to Martin Brungard.

You should also be measuring your pH at 20 minutes into the mash, it will gradually rise throughout the mash.

Brewing is really not a perfectly exact science for the homebrewer. If your pH is off by 0.05 then you're within the accuracy of your instrument and variability of your ingredients and water. Again, with your FG only off by 2 points, its probably just natural variability inherent in small-batch brewing.

 

[Smellyglove]

I guess I just need a few more brews on this system to dial things in. I can't even clone my own beers. that's pretty funny.

 

[Smellyglove]

This horse needs another beating. I can't let it go.

One thing I'm currently researching is if a hard boil does affect the attenutation. I'm thinking caramelization.

I'n my previous system I couldn't get any vigorous boil, it was just more or less bubbling along for the entire boil.

In this setup I'm boiling like crazy, but I adjust my evaporation using the lid. I was at about 14% boiloff before, and now I'm at 15%, but the boil is way more stronger than in the other setup.

 

[TheMadKing]

The only affect I know about from boiling is maillard reactions which primarily influence color. There are a few Carmel flavor compounds produced, but as far as influencing attenuation, I've never read anything like that. From my own personal experience I've never noticed a significant difference in attenuation of beers brewed in the winter vs in the summer (my system boils lower in the winter months when it's cold outside).

 

[eric19312]

I'm curious about how and where you are measuring your mash temperature to be so sure it is the same in both systems. If mash temperature is not uniform throughout the system the measurement a temperature at one location is just that. Possibly the new system is heated much more evenly than the old system (due to larger mash volume) and so the temperature you are measuring is much closer to the overall mash temp where as in your old system it might have been somewhat higher than the average or overall temperature.

Also you might want to check calibration on your measuring device.

Another thought is a mash with a sparge is really a pretty long mash if you were not using a mash out the enzyme activity is continuing throughout the 45-60 minute lauter/sparge process. Even if you were not mashing out on the new system you would be reducing the time spent lautering.

 

[kh54s10]

IMO the only attenuation problem was with the US-05.

I personally can't control things well enough to be concerned with 1.013 to 1.106 or 1.012 to 1.014. I get that amount of variance all the time.

In a taste test I probably couldn't tell the difference between a 1.013 or a 1.016 beer.

Were you able to stay within 1 point with the other rig?

Also IMO, there are so many variables that affect attenuation, I would not really look to the rig as the culprit.

 

[Smellyglove]

I'm curious about how and where you are measuring your mash temperature to be so sure it is the same in both systems. If mash temperature is not uniform throughout the system the measurement a temperature at one location is just that. Possibly the new system is heated much more evenly than the old system (due to larger mash volume) and so the temperature you are measuring is much closer to the overall mash temp where as in your old system it might have been somewhat higher than the average or overall temperature.

Also you might want to check calibration on your measuring device.

Another thought is a mash with a sparge is really a pretty long mash if you were not using a mash out the enzyme activity is continuing throughout the 45-60 minute lauter/sparge process. Even if you were not mashing out on the new system you would be reducing the time spent lautering.

I use PT-100 RTS's to read my mash temps. My source of calibration is a Thermapen. I tried it in an ice-bucket and in boiling water, and it checks out. My mash tun RTD shows me a temp which is spot on where I want it to be.

I've always done a mash-out. I've done some more readings. The fluctuation is up to 6 points. Which is a LOT.

I pretty darn sure something's fishy, I don't think this is an "lower you mash temp" issue.

I shot John Palmer a mail, he told me to turn the heat down, as maillard reactions will render some of the sugars unfermentable, as far as i understood it. But what I read from all the sources (very few) about this issue, is that those reactions doesn't mean that much.

I'm boiling harder than in my previous setup, but I just can't understand that it would affect the attenuation to this extent.

Anyhow. I'll try again tomorrow or monday, with a new BK too, and use less power on the induction plate, so in a week I'll see if that did anything to it.

 

[Smellyglove]

By the way. I've also done two split batches where stuff where out of hand. I can't remember the yeasts I used, but they all finished pretty high except for M31 which just chewed the ****s out of the wort. That one was about 10pts lower than the others.

The other split-batch was a hefe, where 380 was one of them. The two other ones were wb-06 and M20, since i'm not familiar with those dry-strains I didn't mention them intitially, and I messed up my log for that batch, but as far as I remember they ended up about two points higher than 380.

All dry yeasts have been rehydrated and added to the wort with a dosage-thing (dunno what it's called in english), to ensure correct pitch amount.

 

[eric19312]

I use PT-100 RTS's to read my mash temps. My source of calibration is a Thermapen. I tried it in an ice-bucket and in boiling water, and it checks out. My mash tun RTD shows me a temp which is spot on where I want it to be.

OK so the thermometer is calibrated.

By location of the measurement I was thinking about my own system. I use direct fire recirculation and measure the temperature of the wort on the outflow of the pump. I really don't know what temperature is in the middle of the mash nor does it matter as controlling temperature at this point gives me generally reproducible attenuation batch to batch. BUT if I tried to move recipe to a different system, I would not necessarily expect exact reproduction of previous result..

However 6 points FG fluctuation seems extreme. I agree with you that you need to be looking for some explanation other than mash temperature. I agree with other comments above that mash thickness should also not have this level of impact on attenuation. Same with water. I think water has impact on efficiency, appearance and taste but not so much on attenuation.

I don't really know much about any of the yeasts you use.

How about the grain? Is it different source? Is it possible somebody gave you crystal instead of base malt?

 

[Smellyglove]

OK so the thermometer is calibrated.

By location of the measurement I was thinking about my own system. I use direct fire recirculation and measure the temperature of the wort on the outflow of the pump. I really don't know what temperature is in the middle of the mash nor does it matter as controlling temperature at this point gives me generally reproducible attenuation batch to batch. BUT if I tried to move recipe to a different system, I would not necessarily expect exact reproduction of previous result..

However 6 points FG fluctuation seems extreme. I agree with you that you need to be looking for some explanation other than mash temperature. I agree with other comments above that mash thickness should also not have this level of impact on attenuation. Same with water. I think water has impact on efficiency, appearance and taste but not so much on attenuation.

I don't really know much about any of the yeasts you use.

How about the grain? Is it different source? Is it possible somebody gave you crystal instead of base malt?

The grain is different. I use mostly Casle Malting now as opposed to BestMalz before, for my base.

I work at a LHBS so I'm picking my own grain and toss it in the mill.

Anyhow. I've not used so much dry yeast before, just a few times. But I just read that Mr.Malty is calculating with 20BN cells/gram, although Fermentis gives 6BN/gram. So my IPA was underpitched by a pack, I used only one instead of two. But, I've been using MrMalty before and just tossed one pack into even larger batches and can't remember having this problem. Besides, it says on the pack it's for 20-30 liters, I'm doing 14. I'll do the same recipe tomorrow and use two packs and a more puny boil.

 

[Smellyglove]

A different question, but stil relevant.

I almost never did a 72C step before. I do now. I calibrated my system to reach desired PBG with that step. After 60 minutes of mashing at 65, I'm usually 2-3-4 points off my target, but when the 72C-step is done I'm on the mark.

Since I "never" did this step in my previous setup, and it was calibrated to reathing PBG after the first saccharification, step. Could it be that I'm extracting more unfermentables now?

 

[Smellyglove]

Anyone else? In general to the topic.

I just measured my IPA. 6 days, down 30 points from 1.059. US-05. I can't see this one will finish where it should either. This is depressing. Fermentation seems visually very healthy, it's just that 5 points per day, mashed at 65, and it's getting slower, seems a bit low..

Edit: I got confused with an APA I also have going. OG was 1.069. That means 40 points down. 6.6 pts per day which seems more reasonable comparing to the activity I've seen in the bucket. Now I'm just curious about what happens next, after the short chained sugars are eaten up.

 

[bonecitybrewco]

Anyone else? In general to the topic.

I just measured my IPA. 6 days, down 30 points from 1.059. US-05. I can't see this one will finish where it should either. This is depressing. Fermentation seems visually very healthy, it's just that 5 points per day, mashed at 65, and it's getting slower, seems a bit low..

Edit: I got confused with an APA I also have going. OG was 1.069. That means 40 points down. 6.6 pts per day which seems more reasonable comparing to the activity I've seen in the bucket. Now I'm just curious about what happens next, after the short chained sugars are eaten up.

I think you're expecting yeast to react at the home brew scale the same way it does in a controlled lab environment. Attention listed generally has a range. Generally that range is at least a few points... kicking yourself over 2 points in homebrewing seems like an exercise in frustration...

 

[Smellyglove]

I think you're expecting yeast to react at the home brew scale the same way it does in a controlled lab environment. Attention listed generally has a range. Generally that range is at least a few points... kicking yourself over 2 points in homebrewing seems like an exercise in frustration...

No I don't.. It's just that it doesn't attenuate to where I'm used to, from different setups, and other peoples experiences with recipes/yeasts , with this new setup. And it's consequent.

Take the us-05 for instance. That one went way high. Usually my attenuation numbers are higher than those given by the yeast-company, because I always mash for good attenuation. If I want lower I use another yeast strain. or if I want slightly lower I mash higher..

The numbers are high,. I want to know why, because I don't want to do any special "tricks" to get the attenuation to where it actually should be. That would just be a bandaid, I'd like to adress til problem at its core, which I can't identify.

I might be perceived as a semantic, maybe I am. But something is off. I've been brewing about 40 batches per year, using mostly the same yeasts, recording lots of data. Being in the brewery and sampling and tending to my babies almost every day. After I moved and built a new setup the attenuation is off.

 

[Smellyglove]

I just found an old google docs sheet where I've tracked my last 40 brews, I thought that sheet was lost but I found it.

The red thread through that sheet is that the beers with a 72C step attenuated lower than the ones without. This raises at least one new question. Conversion not done after 60 minutes at 65c?

 

[jddevinn]

Smelly, did you ever resolve the pump "cavitation" issues you were having in the other thread? With your small HERMS coil is it possible that you are locally overheating the recirculated mash?

 

[Smellyglove]

Smelly, did you ever resolve the pump "cavitation" issues you were having in the other thread? With your small HERMS coil is it possible that you are locally overheating the recirculated mash?

I didn't resolve it per se, but I found the reason to it. It got more extreme after I upgraded from a 3kW element in the herms to a 3.5kW.

It's the water de-gassing from heat. Bubbles get trapped under the False bottom, al LOT of bubbles. Finding their way down to the pump.

I don't overheat the recirculated wort. I set the PID to target mash temp, and that's the maximum. I could overshoot to get a faster temp raise, but then I'd manually had to monitor that thing not to denature the enzymes.

Edit: The way I'm dealing with it is that I wait until my strike-temp is around the corner. Grab some thick brewing-gloves, and then mount the FB. Just before i dough in I just knock my mash paddle against the FB to knock out newly formed bubbles.

Bubbles, this is what I feel about them:

 

[Smellyglove]

It's been a few weeks..

If somebody is curious. It was a combination of dialing down the boil, and staying away from 72C during mashing, and mashing a bit longer/a bit lower. To hit my targets. Obviously old recipes which didn't have the 72C step in them and if I did it now, missed by more than just turning down the boil.

Going from a 3V-setup to a 2V-no sparge is a whooole different experience than I ever could imagine. Beers are starting to turn out great though. More malty, and fuller. Which I didn't achieve before. Was even able to turn out a 1.112 a few weeks earlier. I was expecting to se a ceiling at about 1.105. Still so many parameters to adjust to.