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Messed up a batch, is it fixable?

Hi – I’m pretty new to both all-grain brewing and yeast washing and I’ve clearly messed up on a recent batch. I’d love advice on whether it’s fixable. Right now the batch is stuck with a gravity of 1.032, and it’s way too sweet to consider drinking. I made (at least) two mistakes:

  1. I undershot the temperature when lautering by about 5 deg F (it was my first AG batch and I didn’t realize I needed to warm the tun before adding grain), and I think as a result, I ended up with a gravity of 1.064 (it should have been 1.07).
  2. As I’ve now figured out, I definitely underpitched my yeast for the beer – and then didn’t check the gravity before racking.

Once realized fermentation was stuck, I warmed the beer up to 65 F (maybe a bit high for a hybrid yeast, but I don’t have a lot of options – either it’s in the basement at 40, or it’s in the house at 65), and after a few days of nothing I pitched a healthy amount of new yeast. Since then, it’s been sitting for two weeks and done nothing.

I’m worried that maybe I didn’t do a good job of converting to fermentable sugars?

I’d really appreciate any suggestions (even if it’s just to write the whole batch off). Thanks!

[quote=“Matt5”]Hi – I’m pretty new to both all-grain brewing and yeast washing and I’ve clearly messed up on a recent batch. I’d love advice on whether it’s fixable. Right now the batch is stuck with a gravity of 1.032, and it’s way too sweet to consider drinking. I made (at least) two mistakes:

  1. I undershot the temperature when lautering by about 5 deg F (it was my first AG batch and I didn’t realize I needed to warm the tun before adding grain), and I think as a result, I ended up with a gravity of 1.064 (it should have been 1.07).
  2. As I’ve now figured out, I definitely underpitched my yeast for the beer – and then didn’t check the gravity before racking.

Once realized fermentation was stuck, I warmed the beer up to 65 F (maybe a bit high for a hybrid yeast, but I don’t have a lot of options – either it’s in the basement at 40, or it’s in the house at 65), and after a few days of nothing I pitched a healthy amount of new yeast. Since then, it’s been sitting for two weeks and done nothing.

I’m worried that maybe I didn’t do a good job of converting to fermentable sugars?

I’d really appreciate any suggestions (even if it’s just to write the whole batch off). Thanks![/quote]

What’s a “healthy amount of new yeast”? Like a qt. of slurry? If you did that and still got no further fermentation, you’ve likely done all you can do. You say you undershot the lautering temp…did you mean mash temp? Undershooting the lautering temp doesn’t matter. Undershooting the mash temp will make the beer more fermentable, not less, unless your temp temp was below maybe 146-147F. Being 6 points low on your OG isn’t a big deal and certainly doesn’t account for your current gravity. How much yeast did you originally pitch and what kind? Did you happen to take your current gravity reading with a refractometer? Let’s get answers to that stuff first and go from there.

Hmm… I would suggest leaving it alone for a good long time.

Could you post the grain bill along with the temps you hit (not the temps you tried to hit) if you have them please?

My main suggestion is to do another batch while you wait for this one because you have already learned some very important things which will make a next batch way better, and brewing again will help you ignore the current batch.

What was the primary fermentation temp.

How long did you ferment?

Thanks for the replies! Denny is right, I undershot the mash temp. I meant for a single-infusion at 152; I started at 147 and ended at 145.

I originally pitched Wyeast 1007 (German ale); I brewed at the same time as I was racking an altbier and I pitched about a pint of sludge from the cake of the altbier. I fermented in primary for 10 days, then racked.

When I repitched yeast, I used a pack of Wyeast 2112 (California lager) that I had lying around; I made a starter with 3 pints water and 1 and 3/4 cups DME; I pitched 2 days after I mixed it.

I took my gravity readings with a hydrometer – the floating hollow tube type.

Again - thanks for all of the replies.

Also,

In reply to the Braufessor:

I fermented at around 50-55 for 10 days, then I had the beer in secondary for 8 weeks at 40-45. It’s been 3 weeks at 65 or so.

In reply to Adam20:

The grain bill was:
5 lbs. German Pilsner malt
3 lbs. German Vienna malt
3 lbs. German Munich Malt
1 lbs. German Dark Munich Malt
0.5 lbs. Briess Caramel 80
0.5 lbs. English Black Malt
0.5 lbs. English Chocolate Malt
0.5 lbs. Briess Caramel 120

And in addition to which, I added 1 lb DME and 1 lb amber extract when I realized that my yield was going to be bad (the 1.064 takes the extract into account).

With the munich/vienna malts and all that crystal,
I’d say she’s done.

One pound of crystal malt in that batch shouldn’t leave you that high and while the temps got a bit low, it should mash okay. I wonder if your gravity readings were off in part by low temperatures? Also, have you calibrated your thermometer to true it (poor attenuation usually is associated with a higher mash temperature range)? Adding those extracts would allow for a slightly greater finishing gravity, perhaps, as well, but not that much.

I brew with Munich and Vienna all the time and with them you can still finish in the 1.010-1.013 range. I will be interested in hearing from others. As a last resort, you can go sour with the beer by adding some bacteria - it can work with those sugars…

Good luck - brew again as someone said. It is the best way to refine your technique.

I hope your right,
I think I lumped all the special malts together.
Seems like alot of kilned malts.
Maybe your hydrometer went crap on you.
You could actually have pulled a pretty high OG with that grain bill and not known it.
Thats one of the workhorse yeasts, but maybe it was just too much.
Or the recipe/style is supposed to finish in that range?
Something seems wacky. Hope you figure it out.

You’re in batch-saving mode now, so drastic measures are called for. Wrap a heating pad around the fermenter, set it on low, then cover with a blanket - get the beer temp into the mid- to upper-70s. Once it’s warm, rouse the yeast at least once per day.

+1 absolutely!

I just assumed that it wasnt just an undershooting of temperature. The combination of that much crystal and the undershot mash temp you end up with a fairly unfermentable wort. But it being only a pound total, you should be able to squeeze some points out with what shadetree suggests.

Hey on a side note fo my own information, Are Munich and Vienna Malts base malts?

Yep.

No, I haven’t – good point. I’d guess my thermometer isn’t great, and will calibrate it. I’m actually working with a digital meat thermometer (cue the laughter, I know), and I’ve actually tried to find a more accurate replacement, but I haven’t seen anything get good ratings on Northern Brewer (other than thermometers intended to be installed in a brewpot, that is). Does anyone have any suggestions?

[quote=“ynotbrusum”]As a last resort, you can go sour with the beer by adding some bacteria - it can work with those sugars…

Good luck - brew again as someone said. It is the best way to refine your technique.[/quote]

Thanks to both of you! I brew (what I think is) pretty often, and just racked a bock which appears to have come out well; I’ll probably try another batch next weekend. Live and learn, I guess. Thanks for the suggestion on souring – I’ll definitely give that a shot if I can’t find another way to fix things.

Thanks for the suggestion. I don’t have a heating pad, but I can make a warm water bath and change the water out every day. Do you think that would do? How hard should I push rousing the yeast? Some stirring/shaking, or should I go as far as transferring to a bucket where I could attempt to aerate, etc.?

Thanks to everyone for the replies!

Thanks for the suggestion. I don’t have a heating pad, but I can make a warm water bath and change the water out every day. Do you think that would do? How hard should I push rousing the yeast? Some stirring/shaking, or should I go as far as transferring to a bucket where I could attempt to aerate, etc.?

Thanks to everyone for the replies![/quote]

Whatever you can do to get the temp to at least 72F, or higher as Shadetree says, and preferably maintain that temp consistently. Just swirling your fermenter enough to get the yeast a bit up from off of the bottom works well, especially if you are doing that daily. I sometimes use a radiator style electric heater hooked up to a temp controller in a closet. Some folks use an aquarium heater in a water bath.

A basic space heater works well too.

40 is freaking low even for a lager. If you’re planning on ferming in the basement, it’s time to get a brew belt or a permanent heating pad.

A quick update (and another thank you to everyone who responded): I roused the yeast and raised the temperature as suggested, and thought I was out of luck – no bubbling in the air lock, no signs of fermentation on the beer.

So, I was getting ready to try souring, and did one last check of the gravity/taste – and it’s down to 1.018 and the extra sweetness is gone.

Again, thanks to everyone who offered advice – it feels great to have saved this batch!

Glad that you got it turned around! As a side note, especially if you are fermenting in a bucket, it is often the case that you won’t see bubbling from outgassing, while nevertheless fermentation is ongoing, sometimes strongly. The buckets just don’t seal solidly many times, and sometimes have a fairly large headspace.

You should check the gravity a couple days apart to make sure it is fermented out - see that it has stopped dropping. With your stated low mash temp, you might go a few points lower than 1.018.

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