Low F.G. after low mash temp

[Mark10409]

Hello,
I had a partial mash kit that I done a few weeks ago. Long story short, the mash temp ended up at 140F after 1hr, I forgot to pre-heat tun. I went ahead and finished it anyways. The O.G. after 60 min boil was 1.050. After 2 weeks in the fermenter the S.G. was 1.023, I let it go another week and it did not budge.. 1.023 after 3 weeks. Is it worth the time and effort to bottle? just looking for opinions..

Thanks,
Mark

 

[carluchi]

1.023 is still pretty high.

There are many reasons for a stuck fermentation (this sounds like one), the first thing I would check is the temp of the wort. Assuming ale and not something like a saison yeast, the temp should be in the 68F range. If its not, move it to a warmer area.

If the temps are in that range, perhaps a gentle swirl to get the yeast off of the bottom might help as well. Note: a swirl is NOT shaking. You are trying to get the yeast off of the bottom of the fermentor, not add oxygen.

There are other things as well, but if you checked everything above and the reading is still stable, keg / bottle and chalk it up to a learning experience.

Good luck

 

[JimRausch]

I agree with carluchi- 1.023 is a high FG, not a low one. And it indicates that she's not finished. I first would check the accuracy of my thermometer to see if perhaps you mashed high, rather than low. A mash temp in the range of 155-160 might give you lots of unfermentable dextrins and a high FG. A mash temp in the 140-145 range would actually give you a more fermentable wort, although you might not get all the fermentables out. So it would be a lower than expected OG, but a fairly low FG. I wouldn't bottle her at 1.023- you might run the risk of fermentation kicking back in and creating bottle bombs. I would also do as carluchi suggested- give her a swirl and warm her up to try and get another 5 -10 points.

 

[Mark10409]

Sorry about that, typo.... I meant to say high F.G. on the title. The kit was from Northern Brewer, Speckled Heifer. The fermenter is in the basement, temp is a steady 65 F. I will open it and give it a swirl. The analog thermometer is pretty close, within a degree or two to my digital. I appreciate the advise and sorry about the confusing title...

 

[JimRausch]

Sorry about that, typo.... I meant to say high F.G. on the title. The kit was from Northern Brewer, Speckled Heifer. The fermenter is in the basement, temp is a steady 65 F. I will open it and give it a swirl. The analog thermometer is pretty close, within a degree or two to my digital. I appreciate the advise and sorry about the confusing title...

AOK. I'm not going to tell you how many times I edited my post above.........

 

[Rob2010SS]

I don't know for sure so im kind of asking everyone. Is this a situation where OP would benefit from getting some amylase enzyme or beano and putting that in the fermenter to get fermentation going again?

 

[seatazzz]

I would try swirling the yeast up and moving to a warmer area, and waiting a few days, before suggesting amylase. Since this was a kit, the yeast may have been out of date. Adding amylase to out of date yeast is asking for trouble.

Another option is finding a homebrew supply store nearby, and buying another packet of yeast that is in date. Add that (after rehydrating) to your wort, give it a gentle swirl, and see what happens. Would bet that will get it moving again.

 

[bracconiere]

partial mash? so you only mashed your crystal malt and used extract for the base malt? looked up the kit...it says, " hey, sometimes a beer is just a beer. Have one."

but i would be careful about bottle bombs, maybe with the two pounds of rahr malt 140f actually didn't convert the starch...and just added gravity...

could use two liter bottles instead of glass and vent them just in case, but i'm a lo-brau brewer that way...

 

[dmtaylor]

Are you by chance measuring FG with a refractometer and not a hydrometer?

 

[Mark10409]

**UPDATE** Well I tried stirring it and waited a week. No change. Then I read the post from dmtaylor about refractometer/hydrometer, Yes, I was using a refractometer, Thanks! rechecked with hydrometer and I was at 1.010.

thanks,
Mark

 

[Mothman]

When using a refractometer for FG readings the alcohol present will give you misleading readings.

You can use online calculators to correct the FG reading,eg Part II here : https://www.brewersfriend.com/refractometer-calculator/