Sanity check - what would your next step be?

For starters, sorry for the length of this post, I wanted to get all the necessary details in here so it wound up quite verbose. Bear with me!

Okay, so I've been brewing AG for nearly a year now and I've got things down to the point where I'm always at least happy with my beers, but naturally I'm always looking to improve. I hate to be one to ask for help with general subjects that have already been covered a million times, but I feel like I've already done a lot of research and taken lots of advice and it's still not working for me. What's bugging me is that I have read all sorts of advice and I've still got some nagging issues:

1) Efficiency - I am consistently in the 70-75 range. I know this isn't awful, but I read of people with similar brewing processes getting in the 80's, so I wonder what I'm missing.
2) Fermentability - I cannot remember the last time I had a beer ferment lower than 1.017 or so, even the ones that should have dropped closer to 1.012 or so (like an ordinary bitter). The beers have all been good, but as expected, the further they fall from the target FG the more sweet and kind of unfinished they taste - not so good when I'm going for a crisp, clean finish.

I use a barley crusher set to around .037 gap - I tried going lower once and got a stuck sparge, I've got a much longer braid now so I'd probably be okay to drop it again, but there's enough flour as it is that I'm not sure it's my main bottleneck.

I mash in a cooler, usually 150-154F depending on recipe, and maintain temps quite well. I mash out with an infusion of boiling water, stirred in vigorously, then recirculate a bit and drain. I batch sparge, splitting the water about evenly between two sparges. Each time I add the water, stir, wait 5-10 mins, recirc a bit, and drain.

I always mash for at least 60 minutes. I don't normally check for starch conversion because the times when I did, it was always complete before 60 minutes was up so I figured I am pretty much safe.

I chill with an IC quite quickly, and every last drop goes into the fermenter, cold break and all, so there is no efficiency lost due to wort left in the kettle. However, in the past I have whirlpooled and avoided the cold break, and it didn't seem to make too much difference.

I have an oxygenation kit, and give each batch about a 60 second blast. I have been using dry yeast a lot lately, and I always rehydrate in 100F water, and always see good activity within 24 hours or so as expected. I have also used liquid yeast with a 1L starter, and one batch was even pitched on a yeast cake. My apartment has been 60-65 degrees most of the winter (a little more or less depending on where I put the carboy).

This last batch I used 5.2 pH stabilizer for the first time, and extended the mash to more like 75 minutes, and the issues remain - my porter's sitting at 1.022 or so (target 1.017), tastes a bit worty, and I barely broke 70% efficiency. Rousing the yeast didn't drop the gravity noticeably. This is with Nottingham, which I know isn't a poor performer normally.

I have been having some issues with boiloff rate - the value I had set in beersmith was too low for my keggle so my final volume was typically low and needed some top-off water. I am sure my efficiency will jump a bit now that I've set the value lower so I am adding another half gallon or more of water to the sparge, rather than post-boil. But I'm not sure how big an improvement it will make, and it still doesn't explain the fermentability.

I feel like I've already tried improving all the usual suspects (crush, doing a mash out, splitting batch sparge into two, using 5.2pH, oxygenating, etc) which is why I wanted to just lay out my whole process and see if anyone else can see any obvious glaring issues that I have somehow overlooked. The efficiency problem I can live with (grain's not THAT expensive yet, knock on wood), but the attenuation issue is really not acceptable as it noticeably affects the character of the beer.

Thanks in advance for any and all advice!

Reading through your post my first thought was to question if you have used several different thermometers to check your mash temp If your thermometer is off by 5 degrees or so you could be mashing too hot, making your wort less fermentable.

Just looking quickly regarding your attenuation problem, 100F might be too hot for your rehydration water, but I do not even pretend to know much about dealing with dry yeast. However, your fermentation temperature sounds pretty low. Mid to low 60s might be fine for the early phases of an ale fermentation, but the low temperatures could lead to premature yeast flocculation, especially with British style yeasts (which tend to be more flocculant in the first place). If you were fermenting an Ordinary Bitter or English-style porter at an ambient temperature below 65F, even for a short time, I would expect you to have a difficult time reaching your target FG. When your temperatures get down to that level, check into ways to warm them up.


TL

I have a fixed gap mill .45. When I started using 5.2 I saw some but little change in mash efficiency.

The largest improvement I have seen was achieved with a recirculated mash coupled with using a mud mixer for dough in. Prior to those changes, I was getting ~75%. After, I get a consistent jump up to ~80-85%.

You don't say how thick or thin you mash. What's the grain/water ratio?
Thicker mashes produce less fermentability; thinner just the opposite.

Thinner mashes at a longer time will produce a lower FG.

Without knowing more about the yeast, I'd try to get the fermentation temp up to upper 60's-70F.

conpewter said:

Reading through your post my first thought was to question if you have used several different thermometers to check your mash temp If your thermometer is off by 5 degrees or so you could be mashing too hot, making your wort less fermentable.

Click to expand...

Ah, that's one thing I forgot to mention - I have FOUR digital thermometers and one analog one, and I checked them all at once in a cup of warm water and they all read within about 1 degree F of each other, so I think I'm safe there.

TexLaw said:

Just looking quickly regarding your attenuation problem, 100F might be too hot for your rehydration water, but I do not even pretend to know much about dealing with dry yeast. However, your fermentation temperature sounds pretty low. Mid to low 60s might be fine for the early phases of an ale fermentation, but the low temperatures could lead to premature yeast flocculation, especially with British style yeasts (which tend to be more flocculant in the first place). If you were fermenting an Ordinary Bitter or English-style porter at an ambient temperature below 65F, even for a short time, I would expect you to have a difficult time reaching your target FG. When your temperatures get down to that level, check into ways to warm them up.

Click to expand...

100F is what I've seen in rehydration instructions from yeast manufacturers, etc. Since I've also pitched liquid yeast starters and even a yeast cake, I think I'm probably doing okay on the yeast side of things.

Good point about the temps though, and maybe as summer approaches things will improve. I did have a couple batches that fermented in a back room and dropped just below 60, but most of them have been in the living room area which is near the heater and pretty reliably stayed at 65ish, though probably stayed below 70F at nearly all times. Perhaps I'll stick my current batch (porter) even closer to the heater for a few days to get it around 68-70 and see if it picks up at all. Thanks for the advice!

GilaMinumBeer said:

I have a fixed gap mill .45. When I started using 5.2 I saw some but little change in mash efficiency.

The largest improvement I have seen was achieved with a recirculated mash coupled with using a mud mixer for dough in. Prior to those changes, I was getting ~75%. After, I get a consistent jump up to ~80-85%.

Click to expand...

I just recently got a pump and I've only done a recirculated mash once. IIRC the efficiency was a bit higher, but that was also a low-gravity bitter so I expected an efficiency boost anyway. I am in the process of putting together a HERMS setup in which case I'll always be recirculating during the mash, so hopefully my efficiency will go up as a result!

DaleJ said:

You don't say how thick or thin you mash. What's the grain/water ratio?
Thicker mashes produce less fermentability; thinner just the opposite.

Click to expand...

I almost always leave it at the default in beersmith, (I think it's 1.25qt/lb) which I thought was pretty middle-of-the-road.

Thanks everyone for all the advice so far, I already feel a lot better having a couple of strong possibilities for improving the situation that I hadn't thought of before.

So you are ready to push through the next barrier on the way to better beer. Here are some pointers:

Regarding your efficiency, read up on mash pH:

Understanding mash pH, How to brew

Try to understand this and get yourself some good pH measuring strips (colorpHast). This way you get some predictability into your mash pH. Also read up on how the lauter efficiency for batch sparging is affected:

Batch sparging analysis

If you are fly sparging, try batch sparging. Learn how the efficiency is calculated and do these calculations by hand. When using Software you never know what exactly is meant with all the efficiency numbers that are given there. You are interested into the Efficiency that determines how much of the potential extract from the grain did you get into your boil kettle. This efficieny is affected by the mash and the lauter efficiency. Try to figure out where and why you are loosing something.

Regarding the attenuation, read this:

Understanding Attenuation

And learn how to do this test:

Fast Ferment Test

This test is crucial as it will tell you if your attenuation problems come from mashing or fermentation. Without knowing that you might be tweaking the wrong thing.

I’m at a similar point, though my problems are different. The beers are good and oftentimes even great, but I’m still having problems recreating an authentic German flavor profile for most of them. There is also a pesky stability problem that shows up occasionally and which I will hopefully figure out pretty soon. All of that takes a lot of brewing and the incremental gains are by far not as significant as they were early on in the hobby.

Kai

Interesting problem. I was going to suggest thermometers too. It would be worth while to try fermenting a little warmer. I ferment in the mid 60s for my Bitters, but I use an American yeast, so I am sure it makes a difference.

Kaiser said:

And learn how to do this test:

Fast Ferment Test

This test is crucial as it will tell you if your attenuation problems come from mashing or fermentation. Without knowing that you might be tweaking the wrong thing.

Click to expand...

Thanks very much for that. Like you, I love the science side of brewing, so one more scientific test I can use to narrow down my problems is very welcome.

Great site by the way, a lot of very useful articles - I think I'll probably be using your Crush Evaluation article to fine-tune the crush with my mill, in addition to all these other changes.

I think 100º is a bit too warm for rehydrating most dry yeast. SafAle dry yeast should be rehydrated at 75º - 86º, and Nottingham at 86º - 95º. This probably won't make much of a difference, but it's something to think about.

How are you measuring your wort volume? A 2-qt error can make the difference between reading 1.045 and 1.050 on your OG, which will obviously make a difference in your efficiency calculation.

Thinking broadly, there are measurement and calibration issues, and then there are process issues. Once you're sure you are measuring accurately and precisely then move on to process considerations.

Good luck! Enjoy the journey!

I would try pushing your mash to 90 minutes and see what that does for the attenuation. The longer you give the beta to work, the lower your FG.

Also, try making one change at a time so you can figure out what part of the process is giving you problems.

Beerthoven said:

How are you measuring your wort volume? A 2-qt error can make the difference between reading 1.045 and 1.050 on your OG, which will obviously make a difference in your efficiency calculation.

Thinking broadly, there are measurement and calibration issues, and then there are process issues. Once you're sure you are measuring accurately and precisely then move on to process considerations.

Click to expand...

I've got a 4-qt graduated container I got from a restaurant supply store that I use for measuring out water volumes. I filled up a better bottle gallon by gallon and used a sharpie to mark off the gallon levels for 1, 2, 3, 4, 5, 5.25, and 5.5 - and that's what I use to determine final volume into the fermenter. Similarly, I filled up my keggle gallon by gallon and marked off gallon marks on my mash paddle (using it as a dipstick) to measure pre-boil volumes.

I suppose it would be worth my while to double-check the volume markings with repeated measurements just to be sure.

jdoiv said:

I would try pushing your mash to 90 minutes and see what that does for the attenuation. The longer you give the beta to work, the lower your FG.

Click to expand...

Yeah, I think I will be doing that next time. This last batch I bumped up to 75 minutes, and 90 is probably even better for safety.

jdoiv said:

Also, try making one change at a time so you can figure out what part of the process is giving you problems.

Click to expand...

Man, wouldn't I love to, for my own curiosity and edification if nothing else. But lately I've had so few chances to brew it might be tough for me to do so. We'll see!

As far as your attenuation is concerned--what do your recipes look like?

I was having attenuation problems until I started reducing my specialty grains to 8-15%.

maltMonkey said:

As far as your attenuation is concerned--what do your recipes look like?

I was having attenuation problems until I started reducing my specialty grains to 8-15%.

Click to expand...

I use beersmith to formulate all my recipes (which calculates the expected FG automatically), and in addition, most of the recipes I brew are tweaked versions of recipes from reputable sources (ie - Jamil Zainasheff, plus recipes from the database), so I have a good indication of what the FG should be in all cases. So, when I say I'm getting a high FG (and thus poor attenuation) it's always relative to the target FG. For instance, I've had a beer that should have dropped to 1.012 finish around 1.017, and my current porter which should finish at 1.017 is currently sitting solidly at about 1.022.

Funkenjaeger said:

I use beersmith to formulate all my recipes (which calculates the expected FG automatically), and in addition, most of the recipes I brew are tweaked versions of recipes from reputable sources (ie - Jamil Zainasheff, plus recipes from the database), so I have a good indication of what the FG should be in all cases.

Click to expand...

You've got to remember that BeerSmith will not take the fermentability of the grains into account when giving you a final gravity estimate. All it does is take the OG and apply the attenuation rate of the yeast you chose. For example, you can make a recipe in beersmith that is 10lbs of crystal malt and nothing else: Beersmith reports an OG of 1.043 and a FG of 1.011.

maltMonkey said:

You've got to remember that BeerSmith will not take the fermentability of the grains into account when giving you a final gravity estimate. All it does is take the OG and apply the attenuation rate of the yeast you chose. For example, you can make a recipe in beersmith that is 10lbs of crystal malt and nothing else: Beersmith reports an OG of 1.043 and a FG of 1.011.

Click to expand...

Yes that's why I consider the calculated FG BS and I'd rather not have it there at all. It just causes more confusion than being a help.

Kai

And, I notice that you have the Rogue Pacman yeast on slants. It maxes out lower, at about 70% AA, so figure that in when predicting your target FG.


TL

I knew that the beersmith FG calculations weren't perfect but I didn't know they were that worthless. Oh well, good to at least know that invalid target FG's may have been partly to blame for my results not matching the recipes. From now on I'll pay more attention to the target FG's, particularly comparing them to the original recipe in cases where I'm using an established recipe from some place, etc.

Still, I don't think that's entirely it - 1.022 still seems too high for my porter. I've put it in front of the heating vent to warm it up a bit to see if it ferments a bit more - the thermometer on the carboy was reading 66F, hopefully I can get it up to 68-70.

TexLaw said:

And, I notice that you have the Rogue Pacman yeast on slants. It maxes out lower, at about 70% AA, so figure that in when predicting your target FG.

Click to expand...

Yeah, I found that out the hard way already. I did a 10g batch of ordinary bitter, pitched nottingham on half and pacman on the other half. The nottingham finished several points high, but the pacman finished several points higher than that... Considering how low the OG was in the first place, I almost would have been better off just drinking the unfermented wort...

What was your recipe and OG for your porter?

According to my super accurate finishing hydrometer, my FG's are also higher than they ought to be. However, when I took the gravity of some 60 degree water with said super accurate hydrometer, it read 1.004!
You may want to calibrate your hydrometer.
The next thing is how long do you leave the been in the fermenter? At your temperatures it could take 4 - 5 weeks to complete fermenting.

-a.

ajf said:

According to my super accurate finishing hydrometer, my FG's are also higher than they ought to be. However, when I took the gravity of some 60 degree water with said super accurate hydrometer, it read 1.004!
You may want to calibrate your hydrometer.
The next thing is how long do you leave the been in the fermenter? At your temperatures it could take 4 - 5 weeks to complete fermenting.

Click to expand...

I've tested my hydrometer in room temp distilled water and it reads 1.002, so I always subtract .002 from my readings - thus all the ones I've said are already compensated.

Being busy, I've often left things in the fermenter for quite a while, some for a little over a month. The porter's been in primary for close to 2 weeks and has been pretty much quiet since the vigorous fermentation died down 3-4 days in.

I'll try to get my porter recipe up later, if I can manage to extract it from beersmith in my presently rather broken install of Ubuntu...

Thanks for this post- you saved me from having to post an almost identical issue, except FG for me is not a problem. The responses here are a big help!