Rookie all-grainer needs some advice on stalled fermentations

[sinned34]

I apologize for making my first post here such a long one, but I just need some expert advice from my fellow homebrewers.

I've been homebrewing using beer kits (Coopers, Muntons, Brew House) for a year and a half now, and, other than one infected beer from a no-name can of hopped extract, I've never had any problems in 24 batches. This summer, after much lurking here and on other homebrew sites, I finally made the jump into all grain after building a mash tun from a cooler. However, I'm now having major problems with stalled fermentation after batch sparging.

For my first batch of beer, a pale ale, my mash wound up being way too cold, starting at about 149 F and ending at 135 after 60 minutes. My mashout temp was about 150 F. My efficiency was a very crappy 55%. I used a packet of Coopers dry yeast, which I've never had any problems with. My OG was 1.036, and my fermentation stalled at 1.022. I read a bunch of threads and posts about stalled fermentation and I figure it's because I missed my mash temperature.

My second batch, I tried the same recipe, but fixed some of my mash temp problems, mashing in at 153 F, ending at 145 F after 60 mins, and mashing out at 158 F. My efficiency went up slightly to about 60%. I used another packet of Coopers yeast, and my fermentation completed successfully, going from OG of 1.042 down to 1.008 FG. After bottling, it's a beer I'm fairly proud of.

Reading a thread that recommended racking a stalled fermentation onto a good yeast cake, I racked my first beer onto the yeast from my second pale ale. The gravity didn't budge in the slightest, leaving me again thinking that the problem was my mash temp, and that the sugars I got out of the malt are basically unfermentable.

My third try, I did a brown ale, and was good on my mash temperatures again, starting at 156 F, ending at 147 F after 60 minutes, and mashing out at 175 F. My efficiency went up slightly to about 65%. I actively stirred the wort with a plastic spoon for about five minutes. I again used the Coopers yeast, and from an OG of 1.044, it stalled at 1.022. I went back to the forums again, and tried adding 3 oz of dextrose and 2.5 tsp of yeast nutrient to the brown ale, then gently shook up the wort. There has been no change.

Now I'm worried about my last beer, another variation of pale ale. I hit pretty much the same mash temperatures as my brown ale, but for some unknown reason my efficiency skyrocketed up to around 80-85%, giving me an OG of 1.052. I also added about 5g of brewer's yeast to the last 15 mins of the boil to act as yeast nutrient. After chilling, I used a big whisk to stir the living hell out of the wort for 10 minutes to oxygenate it, then I added a 2L starter I made the previous day from some washed WYeast 1098 I obtained from my last Brew House kit I made six weeks ago. I got possibly the worst krausen I've ever seen on a beer, but I have the deepest cake I've ever had. It's now five days later, and my beers have always fermented out by day four, but the gravity hasn't yet dropped below 1.032. I'll continue to monitor, but I'm concerned this fermentation has also stalled.

What am I doing wrong? I would appreciate any advice you fine folks have to offer.

 

[djfriesen]

You say stalled, but what are the test intervals? Is it possible it was just taking a while to finish? Sounds like you nailed the one problem, no fermentable sugars, but without a little more detail on recipes/process it's tough to diagnose.

 

[tmurph6]

What temperature are you pitching at and fermenting at?

 

[sinned34]

Sorry, I forgot to mention my test interval was two weeks' time. I generally ferment for two weeks in primary and two weeks in secondary, then keg or bottle. I usually only measure final gravity just before I transfer to secondary, but thanks to my fermentation problems, I'm starting to test earlier in the hopes of catching issues earlier.

I pitch and ferment at about 68-70 degrees F, although thanks to an issue with air conditioning, the first beer wound up spending a day at about 76-78 F, and my second ale wound up spending a night at about 62 F.

My pale ale recipe was about 12 lbs Gambrinus ESB malt (I live an hour's drive from Gambrinus, so I can pick up a 55 lb bag for $25), with 1.5 lbs caramel 40 malt. I aim to mash at 155 F for an hour (my mash tun is way too big, so the extra space causes it to lose about 10 degrees during that hour), slowly drain (about 15 minutes), then sparge out at 170. Hop schedule was 1 oz Northern Brewer at 60 minutes, 1 oz Willamette at 15 minutes.

My brown ale was 10 lbs ESB malt, 1.5 lbs caramel 60, .5 lbs wheat, and .4 lb chocolate malt. I tried the same mash as with my pale ale. Hop schedule was .5 oz Northern Brewer at 60 minutes, 1 oz East Kent Goldings at 15 minutes.

Does that help?

 

[djfriesen]

Temperature is the only thing jumping out at me. What temps are you fermenting at? Any chance the yeast is getting shocked by cool temps and going dormant?

 

[muthafuggle]

10 degrees seems like a big loss of temp. Are you pre-heating your mash tun? If your temp is dropping too low too early in the mash you might not be converting to sugars. Try pre heating your tun and maybe a 90 minute mash, too.

Also, I noticed you are mashing out way too cool. Mashout should be around 170-175 to stop the conversion.

 

[JuanMoore]

I agree that 10F/hr seems like a massive temp loss, even using a drastically oversized cooler. What temp are you striking at to achieve the initial rest temp? How well and for how long are you stirring the grains at dough in before taking the initial temp reading? Are you pre-heating the mash tun at all? Are you opening the mash tun at all during the mash? Have you calibrated your thermometer to make sure it's accurate?

 

[Justibone]

Last I checked, Gambrinus was weak in the enzyme department. I may be wrong about that, but that was my impression.

Also, I agree with the temperature issue. After the first week, when the bulk of fermentation is complete, I let my beers warm up. Sometimes they'll drop another eight to ten points after that, but side-reactions (off-flavors) are not detectable by me. (I have yet to have a BJCP judge try my beer, though.)

There are two things you didn't try, one good, and one not-so-good. The first (good) option is adding champagne yeast. They are tough little buggers and can eat sugars that other yeast choke and die on. The second not-as-good option is "Bean-O(tm)". Yep, those li'l pills that reduce gas or bloating or whatever from eating beans. Crush up a few tablets, dissolve in 140F water for at least ten minutes, then pour into your beer. Some have gotten good results from that way, some have gotten either undesirable or no results, but if it works it will be more drinkable than your current "hop syrup".

One final note: when my buddy and I did a batch of barleywine and bottled it, after six months it was *awesome*. Rich and caramelly and uber-delicious. Best beer I've ever brewed. Best beer I've ever *had*. Now, another six months later, carbonation has shot up and the caramel has all but disappeared. *weep*.

So, time does heal almost all beer wounds, but if you choose to bottle a sweet beer on the off-chance it will finish eventually, don't add bottling sugar or beer bombs could result. Another solution would be to just move it to a glass carboy or Better Bottle(tm) to age for a few months.

TL;DR - champagne yeast: good option. Bean-O(tm): less good option.

 

[waldoar15]

Have you calibrated your thermometer to see if it's accurate?

 

[JonM]

10 degrees seems like a big loss of temp. Are you pre-heating your mash tun? If your temp is dropping too low too early in the mash you might not be converting to sugars. Try pre heating your tun and maybe a 90 minute mash, too.

Also, I noticed you are mashing out way too cool. Mashout should be around 170-175 to stop the conversion.

I used to lose temp too - I use a round cooler for the mash tun, so I cut some circles out of 3/4 inch foam, same size as the inside diameter of the cooler, then I put them in one of those heat-resistant crock pot liner bags and rest it on top of the mash. Temp doesn't budge now.

 

[Elweydoloco]

Everyone is in aggreeance with the 10 degree an hour drop is pretty substantial.

The bad thing now though, is you're going to have to play with keeping it consistant or preheating your tun. Wrapping it in towels throwing hotter water in first and then letting it slowly come down to 155. Then watch your temp thrown in warm water to keep it up where you need it.

Maybe the fermentables just aren't getting there as the mash temps are low.

 

[Mpavlik22]

I do not have an answer to your question, but you said your first all grain try you mashed in around 149 F. That would actually produce more fermentable wort then say mashing in around 154F. Part of the issue may be that you were losing ~10F over the 60 min mash. That can affect your enzymatic conversion.

 

[Elweydoloco]

I do not have an answer to your question, but you said your first all grain try you mashed in around 149 F. That would actually produce more fermentable wort then say mashing in around 154F. Part of the issue may be that you were losing ~10F over the 60 min mash. That can affect your enzymatic conversion.

Well you have a point there.

M.A.L.T.

More Alcohol Less Temperature

 

[frazier]

OK everyone is talking about the temps, but I have another question for the OP: you say you get your base grain in a 55 lb. bag - do you crush it yourself? Maybe you need a finer crush. What mill do you use?

 

[waldoar15]

What temps are you striking at? I'm only asking because you say you're a new AG brewer and I've seen new people here confuse mash temp with strike water temps before. i.e. they were striking with mash temp water.

 

[sinned34]

Wow, thank you everyone for all the helpful responses!

My fermenting temp is pretty stable at about 70 degrees. My "fermentation chamber" is a spare bedroom that tends to keep a couple of degrees cooler than the rest of the house.

My mash tun is probably way oversized - it's made from a Coleman Xtreme 70 qt (66 L) cooler, in which I'm making 23 L batches (boiling down from 28 L). I figured it wouldn't lose heat much, but I was apparently wrong, and was pretty disappointed to see how much temp I'm losing. I'm contemplating picking up a smaller cooler and putting all my mash tun parts into it instead. At the very least, I'll start wrapping blankets around my mash tun to see if that helps. I was also thinking of something along the lines of JonM's suggestion of putting sanitized foam on top of the mash.

For pre-heating my mash tun, I start by putting 185-190 F strike water in my cooler for a couple of minutes with the top closed, then I dump my grain in and stir for about 10 minutes, at which point the temp usually hits about 155 F. I then close the lid and leave it for 30 minutes, when I open it again to check temperature. Once, when I was checking it too much, I saw it had hit 145 after 30 minutes, I added 4L of 180 F water and stirred for 2 minutes, which brought the temp back up to 152 F. After another 30 minutes (60 minutes total), the final temp was 150 F. I usually mash out (sparge out?) with 190 F water, which usually puts me up to 170 F (although it's about 165 F when the last drops of wort come out of the mash tun).

I've got two thermometers, one is a candy thermometer that I put in my mash tun and another that came with the turkey fryer that I'm using for boiling my wort. They both match up with the same temperatures and seem to be accurate for boiling water, but I suppose it's possible they are both out of whack in the 130-160 F range.

I still have my first pale ale in secondary (it's been in there for three weeks now), and my brown ale in primary (it's third week there) so maybe I'll take Justibone's suggestion of trying champagne yeast. I was planning on kegging them instead of bottling so I don't have to worry about bottle bombs.

As for a crush, I've been borrowing a corona mill at a local U-Brew place and I'm relying on their expertise for how fine a crush to use. Sadly, they are an extract brew place, so I think they know about as much about crushing grain as I do. I've begged my wife to get me a Barley Crusher for Christmas this year.

 

[sinned34]

Just as I feared, my final, high-gravity pale ale that I put into primary a week ago (last Sunday) has stopped fermenting and has been stuck at 1.032 since Wednesday.

I've tried putting champagne yeast into it, as Justibone suggested. I'll see if anything changes in the next couple of days. For my next beers, I'm going to do everything I can to recreate exactly what I did on my second pale ale that turned out very pleasant.

I appreciate everyone's assistance, but feel free to let me know if anyone else has any further suggestions.

Thanks.

 

[Justibone]

I think that grain crush shows up in efficiency, not in finishing at too high a gravity.

You might have an issue with your water, or yeast nutrients, but you said you took care of that by boiling in some yeast. Have you tried pitching a new beer onto an old yeast cake? If that worked, then you would know it was a yeast problem and not an all-grain problem. I'm basically just spitballing here.

You didn't have this problem with extract brewing though, IIRC, so maybe that's not the problem.

If the champagne yeast doesn't work, and the Bean-O does, then you've got too many unfermentable sugars. (Brew a beer that's supposed to be dry if you're going to try the Bean-O.) If the champagne yeast does work, it might still mean that you've got too many unfermentable sugars... hmm. This is a thorny one.

 

[sinned34]

You might have an issue with your water, or yeast nutrients, but you said you took care of that by boiling in some yeast. Have you tried pitching a new beer onto an old yeast cake? If that worked, then you would know it was a yeast problem and not an all-grain problem. I'm basically just spitballing here.

You didn't have this problem with extract brewing though, IIRC, so maybe that's not the problem.

Yes, I did try pitching one of my beers that had a stalled fermentation onto a yeast cake from a successfully fermented beer. It didn't jump-start any further alcohol production.

If the champagne yeast doesn't work, and the Bean-O does, then you've got too many unfermentable sugars. (Brew a beer that's supposed to be dry if you're going to try the Bean-O.) If the champagne yeast does work, it might still mean that you've got too many unfermentable sugars... hmm. This is a thorny one.

I think you're definitely right: it is a problem with getting too many unfermentable sugars. From what I understand, I should be getting lots more fermentable sugars, because my main issue seems to be (or at least, I think it is) that my mash temperatures have been too cool. However, I've only had one successfully finished fermentation in four tries now, and that beer did turn out to be very dry.

I'll certainly try the champagne yeast, followed by Bean-O if that doesn't work. Otherwise, I'll just be having a few low-alcohol, overly sweet beers. The weather is starting to get cold, so I'll be returning to extract/kit brewing for the winter, then I can regroup and try again in the spring.

 

[Justibone]

I think you're definitely right: it is a problem with getting too many unfermentable sugars. From what I understand, I should be getting lots more fermentable sugars, because my main issue seems to be (or at least, I think it is) that my mash temperatures have been too cool. However, I've only had one successfully finished fermentation in four tries now, and that beer did turn out to be very dry.

Try a 90 minute mash. If you want to keep working on AG over the winter, but you don't want to do it outside, check my blog posts. I just did a one gallon batch on an electric range indoors, AG, with minimal equipment. (There's no need for you to do minimal equipment like I did; I was just seeing if it could be done, which, BTW, it can. :rockin: )

I'd say keep at it, and get back on that horse, but at ~$7 a batch it's far more economical to manage than paying ~$30+ and ending up with sugar water.

 

[sinned34]

Try a 90 minute mash. If you want to keep working on AG over the winter, but you don't want to do it outside, check my blog posts. I just did a one gallon batch on an electric range indoors, AG, with minimal equipment. (There's no need for you to do minimal equipment like I did; I was just seeing if it could be done, which, BTW, it can. :rockin: )

That's actually a good idea. I don't feel like spending six hours outside in minus five Celsius weather trying to do a mash, but a small 2 gallon batch should be quite feasible to do indoors (with the wife's permission, of course). I just have to figure out what I can use for a mash tun. I'll check out your blog posts to see what you did.

I'd say keep at it, and get back on that horse, but at ~$7 a batch it's far more economical to manage than paying ~$30+ and ending up with sugar water.

I agree that I obviously need a lot more practice, but price isn't really an issue. Since I pick up a 55 lb bag of my base grain at Gambrinus for about twenty five dollars, a full 23L batch of beer generally runs me ten bucks or less. Sadly, there's no LHBS in my area, so I wind up paying top dollar for specialty malts and hops from local microbreweries, or else I'd probably be spending six bucks a batch.

I've been bitten by the all-grain bug, and I'll definitely keep trying. Things are just a little frustrating right now because I've never really had any issues brewing, and now I've had three of my first four AG attempts fail, and I'm still not sure exactly what I'm doing wrong yet.

Thanks for your help.

 

[BrewKnurd]

For pre-heating my mash tun, I start by putting 185-190 F strike water in my cooler for a couple of minutes with the top closed, then I dump my grain in and stir for about 10 minutes, at which point the temp usually hits about 155 F.

Ok, I want to preface my comments with a huge caveat that I've not used a cooler mash tun, I just use a kettle and wrap it in a towel for insulation.

185-190 seems hot to me. I don't know how much the temp drops in warming up your cooler, and I also don't know what water/grain ratio you're using, both of which would factor in to what temp you would be targeting. But the fact that you're stirring for 10 minutes and after that period getting down to 155 makes me wonder if you're denaturing enzymes. You lose a pretty decent amount of heat while stirring, and if you're stirring for 10 minutes to get down to an average of 155, that makes me think your initial average temp might be a good bit higher.

Anyways, like I said, have never used a cooler mash tun, so I could be way off on this one.

 

[Justibone]

I've never used an MLT either. I've wrapped my pot with a towel as well. Stirring is a bad idea with a pot, though... but you can "slosh"-stir it on the countertop if you use a trivet. Just don't slosh too much, or get ready to be very uncomfortable and/or have very messy towels.

I mashed in a pasta pot with a lid, and boiled in a chili pot. I'm going to do it again (already have the ingredients), but this time I'll make a half-gallon batch. It's really not much tougher than making spaghetti with your own sauce.

If you get gambrinus or 2-row cheap, I say skip the specialty grains until you figure it out. Wash your yeast a couple times and you could be getting a gallon of beer for a couple of bucks, total.

 

[smalliewader]

I've been dabbling a little in AG brewing on occasion. For space concerns, I do 3 gallon batches. My tun is a 5G bottling bucket, with spigot and Phil's Phalse Bottom. If I use water around 170-175, I get a mash temp right around 155-158 when the grains go in at 1.25-1.5 qt's per pound. Wrapping an old quilt around the bucket with the lid on, I only lose around 3-5* in an hour. I sparge with 170-175 water from another bucket through a Phil's Sparge arm, gravity fed.

Just a thought if you are looking for equipment to do smaller batches indoors, you probably have the majority of it already. It's ghetto, but the old quilt holds a lot of heat in that uninsulated bucket.

 

[Justibone]

If your batch is small enough, a colander is good enough! :rockin:

 

[sinned34]

Ok, I want to preface my comments with a huge caveat that I've not used a cooler mash tun, I just use a kettle and wrap it in a towel for insulation.

185-190 seems hot to me. I don't know how much the temp drops in warming up your cooler, and I also don't know what water/grain ratio you're using, both of which would factor in to what temp you would be targeting. But the fact that you're stirring for 10 minutes and after that period getting down to 155 makes me wonder if you're denaturing enzymes. You lose a pretty decent amount of heat while stirring, and if you're stirring for 10 minutes to get down to an average of 155, that makes me think your initial average temp might be a good bit higher.

Anyways, like I said, have never used a cooler mash tun, so I could be way off on this one.

You know what, I think you`ve hit the nail on the head here.

My first failed beer, I put my grain in my mash tun first, then dumped my 170F strike water onto it. That beer didn't ferment lower than 1.022 FG.

My second beer, which was successful, I put 166F water in my tun, then added the grain and stirred for 5 mins, reaching 149F. After 30 mins, the temp had dropped to 145F, so I put a gallon of 170F water in, which brought the temp back up to 150F. I left it for another 30 mins and drained it, then added sparge water at 170F, which gave me a final temp of 155F.

My third and fourth beers both failed, and I put 180-190F strike water onto the malt. I think I'm going to go back to using 170-175F strike water, and try to fix the amount of temp loss I'm experiencing. I'll return to adding a gallon of 170F water if the temp drops too much.

I'll let you know if this works.

 

[Justibone]

You can always boil longer to get rid of the extra water. Or put a fan blowing on the pot as it boils -- that makes it boil-off a lot faster, I've heard.

 

[seanybubbles]

I think you have a few problems going on sinned34. 1) Your mash tun is way to big and will not be able to hold the temps with that much dead space. 2) You shouldn't need to stir your mash for ten minutes to get down to your target temp, look into software to get your temps right. 3) You should probably invest in a better (more accurate) thermometer. I used a candy thermometer when I started and had the same problems, beers that just wouldn't finish due to inaccurate temps. 4) Do an iodine test to check if your getting full conversion. 5) Make sure your getting a good crush, otherwise your just wasting grain.

Hope this helps......

 

[flabyboy]

my advice would be a smaller cooler with less head space = less heat loss. I also wonder about the accuracy of your thermometers. You may want to think about getting a thermapen or CDN proaccurate. I got the CDN for $15 and have been very happy with it.

I may have missed this, but what are you using for water?