Rising gravity?!

[steveng]

Hi, I hope someone can help before I throw my current brew to the sewers! I've been the victim of a stuck fermentation for my past couple of brews, it's most frustrating.

Having noticed my fermenting IPA had stuck around 1.037 (starting at 1.065) I decided to up the temp in my fermentation chamber by a couple of degrees. Lo and behold, it started again, but only down to 1.031 and then stalled again. So, I decided to give it a bit of a gentle stir (and suggested by the Internet) yesterday. Today, taking a measurement with my refractometer (and adjusted in Beersmith) it's gone back UP to 1.037!

Is this a factor of the stirring and perhaps introducing more sugars from the trub?? Should I be worried, or just give it a couple more days to settle again properly?

This is a small batch, about 8 litres into the fermenter, and I pitched a whole wyeast smack pack (#1056) about 2 and a half weeks ago.

Thanks, any pointers gratefully received!

Steven

 

[MrRook]

Recipe?

 

[Ghillie]

Just pitch more yeast.

There is the possibly that you had stratification of sorts; and when you stirred; you ultimately measured two different "samples".

If you stirred and mixed some of the trub back into suspension, then the wort would naturally become more dense. Thus the alleged jump from 1.031 to 1.037.

There's also the human element with interpreting the gravity readings that can;t be ruled out. We've all made mistakes reading hydrometers.

I'd disregard the refrac reading also, as it requires an accurate hydrometer reading for the calculation with fermenting beer. As you have discrepancies with your hydrometer, your refrac reading is **** on a fish.

 

[Leon103]

I think we need to know more a out the recipes and technique otherwise the problem will never go away.

Are you happy your equipment is accurate?

 

[Dutto]

"Stuck" brews have more solutions than you can shake a stick at but one of the most common is a **** hydrometer that is reading high because the bit of paper inside the tube has shifted. So, first job it to check that the hydrometer reads 1.000 in water at 20*C.

FOR ME there is only one way to tackle a "stuck" brew:

1. Take the lid off the FV and beat it with a sanitised paddle as if it owes me money! (At this stage I class the brew as a "wort" and the extra oxygen doesn't affect it like a completed brew!)
2. Shake in a packet of Wilco Ale Yeast (aka Nottingham Yeast, aka Gervin - 12 Yeast.)
3. Put the FV lid back on and increase the fermentation temperature to 22*C. (I normally brew at 20*C.)
4. Leave it alone for at least to weeks before checking the SG again.

I can't remember a time when this method has failed to re-start the brew so I don't have any further tips.

 

[steveng]

It's a small batch of Raspberry IPA with:

1700.00 g Pale Malt
180.00 g Munich Malt
75.00 g Cara-Pils/Dextrine
75.00 g Caramel/Crystal Malt - 60L
75.00 g Melanoiden Malt

Citra hops and Lactose added towards end of boil and the aforementioned 1056 yeast.

Frozen raspberries added to fermenter after 7 days.

It's a BIAB, 60 min mash at 68.9 C, 60 min boil.

I calibrated my refractometer last night and it was spot on. I think I'll give it a few days to settle from my stirring, check again and go through Dutto's steps if it's still not playing ball.

Thanks,

Steven

 

[jceg316]

I don't use a refractometer but I have read they are for measuring the gravity of wort and not beer, but you will have more experience on this than I will. Anyway, it might be worth measuring with a hydrometer at the correct temperature.

 

[steveng]

There's an apparently complicated calculation between refractometer Brix readings and the real figure for gravity. Beersmith deals with it, given the OG, and I've not really questioned it but I'm veering towards returning to the hydrometer!

 

[xozzx]

For sure you need to use a hydrometer for beer gravity. I use a refractometer for the wort and hydrometer after it has fermented. I have checked the refractometer out of interest and got a gravity of about 1.035 for a beer which hydrometer read 1.010.

Remember you will also have a slightly higher FG as you added lactose.

 

[steveng]

Yeah, I knew it would be higher with the lactose. I will take a hydrometer reading this eve to be sure.