how much to raise temperature? Stuck fermentation

[saeroner]

have a 10 gal IPA in a conical.

Mashed in the mid 150s

Was aiming for OG 1.075 and only got it to 1.049

used 3 packs of US05 and it started up the next day and lasted 2 days.

It's been 3 days of 1.035

It's my brother's batch and he was talking about bottling it (No way).

If i raise the temp up and shake it would that help? How much should i raise the temp? 5 degrees?

 

[Pkrd]

Whats the temperature now?

 

[Yooper]

Just a quick question- you're not using a refractometer to take these readings, correct? If you are, then run and check with a hydrometer.

If you're using a hydrometer, then a new yeast starter needs to be used. But I have a feeling that's not the case.

 

[saeroner]

Just a quick question- you're not using a refractometer to take these readings, correct?

Yes i'm using a refractometer. How did you guess that? anyways i will go buy a hydrometer.

It was fermenting at 66. I slowly raised it to 70

 

[Yooper]

Yes i'm using a refractometer. How did you guess that? anyways i will go buy a hydrometer.

It was fermenting at 66. I slowly raised it to 70

Because a refractometer always does that, as alcohol skews the reading.

There are some calculators online that can help guestimate the proper reading, if you don't have a hydrometer.

Your beer is done, and probably more like 1.010, but you can check it with a hydrometer. http://seanterrill.com/2012/01/06/refractometer-calculator/ has a site with a calculator for this, but you'd still have to know your wort correction factor.

 

[Yooper]

I forgot to add this!

http://seanterrill.com/2010/06/11/refractometer-estimates-of-final-gravity/ is a link to the same site, but it explains how a refractometer works and why it isn't accurate (without correction) once fermentation starts.

 

[dammBrewer]

Just a quick question- you're not using a refractometer to take these readings, correct? If you are, then run and check with a hydrometer.

If you're using a hydrometer, then a new yeast starter needs to be used. But I have a feeling that's not the case.

Yooper hits great advice yet again!

 

[saeroner]

Because a refractometer always does that, as alcohol skews the reading.

There are some calculators online that can help guestimate the proper reading, if you don't have a hydrometer.

Your beer is done, and probably more like 1.010, but you can check it with a hydrometer. http://seanterrill.com/2012/01/06/refractometer-calculator/ has a site with a calculator for this, but you'd still have to know your wort correction factor.

THANKS. I went and checked with a hydro, it says 1.030 -- crap.

So the only other option is to pitch more yeast. I use US05 (dry) should i rehydrate and pitch?

Also, telling my brother bottling this is a bad idea. If yeast don't start up should i just dump the batch?

 

[Yooper]

THANKS. I went and checked with a hydro, it says 1.030 -- crap.

So the only other option is to pitch more yeast. I use US05 (dry) should i rehydrate and pitch?

Also, telling my brother bottling this is a bad idea. If yeast don't start up should i just dump the batch?

It's in a conical? Can you look and see if the krausen has fallen? It'd be hard to fathom a 1.049 beer stalling at 1.030 with even unhealthy yeast.

You can try raising the temperature to 72-75, and I'd do that first before repitching.

The other thing to consider is that maybe there are a lot of unfermentables in this batch for some reason- a too high mash temperature due to a faulty thermometer, a recipe error, etc- so that would be something to look at as well. If the beer is stuck due to something other than faulty yeast, then repitching won't fix it. With two days of visible activity, it seems very odd that the SG only dropped 19 points though, so I would check the hydrometer in plain water to ensure accuracy. Something doesn't add up.

 

[cannman]

You also might have created a ton of non-fermentables that are causing your excessive gravity. How confident are you of your mashing temp?

(oops, Yooper beat me to in in the time I was reading and then posted).

 

[Pam Alexander]

I have the same problem and the mash temp was too high.. what can be done? Add amylase? Anything else?