Problem with either mashing or fermentation

[brelic]

I'm now officially at my wit's end!

I've been managing some pretty nice batches over the past few years, but there seems to be one problem that continually plagues my brews: high finishing gravity.

Over successive beers, I've tried just about everything to correct it... finer crushes, fewer adjuncts, lower mash temps, thinner mashes, decoctions, you name it. Nothing seems to correct it.

I've had about 3 brews out of 12 over the past year finish below 1.020: a belgian blonde, an oatmeal stout, and a pale ale. Two of those (belgian and stout) were decoction mashes.

Does anyone have any tips??? What on earth could I possibly be doing wrong? Fermentation temps are stable, and I've tried fermenting in the 20 C range as well as 16-17 C range.

The only thing left that I can think of is a faulty thermometer. It is a stainless steel analog type... I've been mashing between 149-152 lately to try and increase fermentability, and if the thermometer is faulty, that might be the culprit...

Any thoughts?

Thanks in advance!

 

[s3n8]

I would double check your thermometer. What does it read in ice water and boiling water? A few degrees seems to make a big difference to me. Also, what yeast are you using? I have real good luck with Nottingham and S-05, both finish nice and dry for me. With liquid yeast are you using an appropriate pitching rate (making a starter) for the OG?

 

[brelic]

s3n8 - I've used liquid yeasts with no starter, with 1 L starter, with 2 L starter, and dry yeast on the most recent (SafAle S-04 for a Robust Porter).. first time using dry yeast. OG was 1.054, and 4 days later, it is 1.028-1.030 @ 17-18 C.

I made a Dogfish Head IPA clone a few weeks ago, 2 L starter, Wyeast 1056, OG 1.069, and it finished at 1.018-1.019 and it is *delicious*.

The Robust Porter smells awesome, tastes awesome though a bit sweet, so I'm not *too* worried (though only 3.1% alc. thus far which blows).. but I really want to correct what it is I'm doing wrong.

It must be a thermometer issue. Any recommendations on a digital one?

 

[robertvrabel]

Definitely check your thermometer vs another one. Personally I brought a digital one for about $22 and its been so much more helpful. I learned my old one was about 4-5 degrees higher.

If your using liquid yeast, are you making a starter 3-4 days before?
What temps are you normally fermenting at?

 

[robertvrabel]

I also wanted to note that a FG of 1.018-1.020 is perfectly normal in a lot of different brews. If your FG was stopping at 1.030 then I would say you have a problem... personally I think if your beers taste good, don't worry about it!

 

[weirdboy]

Yeah my guess is mash temps are high, and you should get another, trusted, thermometer to be sure your temps are correct.

Or you are boiling unusually long or somehow scorching the wort a bit.

In my experience S-04 doesn't attenuate as much as some others, but shouldn't be off by as much as you say.


EDIT:
Another possibility that just occurred to me is that your hydrometer could be off. Have you checked the calibration on it recently?

 

[brelic]

robertvrabel - I was always told 1.012ish-1.018ish was the appropriate range (of course, there are exceptions, like wee heavy, etc).

Would LHBS carry digital thermometers? I'll give them a call tomorrow. That's gotta be it.

For starters, I was making them about 36-48 hours ahead of time. Fermentation temps are usually between 17-18 C, but I have also tried 20-21 C with not much difference.

 

[brelic]

weirdboy - Nope, regular 60-70 minute boils.

The hydrometer is about .001-.002 off, so that my water (well water) measures 1.001 or so. Which makes a difference when my FG is 1.020, but I've had a few at 1.024, 1.023, etc. Just feels too high for me.

What are the typical FGs you guys get?

 

[robertvrabel]

This is the digital thermometer I bought. I like it a lot, it takes about 10-15 seconds to get an absolute final reading (only 5 to get an approx)... but its so much easier to use. I don't have to do any guess work on the reading, and its easier to keep it consistent from brew to brew.

http://www.amazon.com/dp/B00064BCPM/?tag=skimlinks_replacement-20

I've had beers finish from 1.012 (my hefeweizen) to 1.024 (oatmeal stout)... all depends on the recipe and mash temperatures I've done.

 

[brelic]

robertvrabel - Thanks for the link. I think I might order it.

 

[weirdboy]

I typically get 70-75% attenuation with S-04. For e.g. my porters and pale ales with that yeast that start in the mid-50's they pretty much always end in the range 1.012-1.016.

 

[ajf]

How long do you mash for? I've found that when mashing below 150F, a longer mash time (say 90 minutes instead of 60) helps to bring the FG down.

-a.

 

[bctdi]

My dial analog thermometer was correct at room temp and boiling, but off by 15-20 degrees between the temps of 120-180......I was being blindsided by that damn thing.Go buy a lab mecury thermometer, they are under 10 bucks and accurate....even if you get a digital one, it`s good to have the mercury one around to check it against every now and then.

 

[DrinkNoH2O]

I bought this thermometer/timer a few weeks ago and it is by far the best tool I've bought for brewing to date:

http://www.amazon.com/gp/product/B000P6FLOY/?tag=skimlinks_replacement-20

When heating water, simply set your target temp, clamp the probe to the pot, and wait for it to beep. That's it! You can also time all of your boils with it. My favorite feature is the ability to drop the probe right in my rubbermaid cooler MLT and seal it up - it keeps a constant reading and the thin probe cable fits under the rim of the cooler no problem. Plus the cable is waterproof/high-temp resistant!

I've also calibrated it again regular analog thermometers and it's completely accurate. At $20 it's a great investment.

 

[brelic]

Thanks for all the advice, folks. A new thermometer is on its way.

In the meantime, if this batch remains stuck at 1.028-1.030ish, is there anything I can do to get it going? I swirled it a few times, and warmed up the room a degree or two to bring it to about 18-19 C.

Other than that, what can be done? Like I mentioned earlier, it tastes nice, but at that level of FG, there is just too much residual sweetness.

 

[weirdboy]

You could add amylase enzyme, but you'll pretty much lose control over the FG after that unless you boil it or something. It will dry your beer out, but quite possibly more dry than you intended.

You could also add a pound or two of sugar. That will tend to dry out/thin out the flavor a bit, but I wouldn't want to stray too much over, say, 15% of the total grain bill.

EDIT: I think if this is a pale ale...adding sugar is going to change its character to something else. Of course, it's already not very much like a pale ale if the FG is close to 1.030, so I guess it's a moot point.

 

[chefchris]

You could add amylase enzyme, but you'll pretty much lose control over the FG after that unless you boil it or something. It will dry your beer out, but quite possibly more dry than you intended.

I second the amylase enzyme. However, I've had the complete opposite results as you. I only see a drop of about 5 points, never had it completely dry a beer out. Had an IPA finish at 1.022, got it down to 1.018. This was an odd IPA with a lot of crystal in it.

 

[brelic]

weirdboy - it's a robust porter, so some maltiness is good. I'll take another reading today to see where it's at.

If amylase can help, might be worth it. Otherwise, this won't be much of a beer.. the alcohol content (3.2%) is more worry than the FG if nothing changes.

 

[midfielder5]

My hydrometer is .004 off, but until I tested it with distilled water I had the same issue. Now I know all is good.

 

[Jmiltime]

This might not help at all but I thought I would throw in a couple of things not said yet. If you have a plastic bucket and it is getting old, I have heard of them getting scratched and harboring bacteria which goes crazy on your yeast and will affect your attenuation percentages. Usually, the beer will have some strange flavors though. I know it's a stretch, but you're at your 'wits end' so I thought I'd mention it.

It sounds like you have been brewing for a while so I don't want to ask a stupid question, but what is the starting gravity of your brews? For beers with an OG of 1.070 an FG of 1.021 is still 70% attenuation. Along with what has already been said, if your gravity is high and your mash temps are high too, 65-70% attenuation is probably about right.

I personally would stay away from the enzymes to correct an OG problem. If there is something wrong in the process, enzymes will mask the problem and can cause unpredictable things to happen to your beer. I think you are on the right track by pinpointing and fixing the issue.

Probably not too helpful, but my 2 cents.

Good luck!