Higher Final Gravity than expected?? HELP

[Zandrello]

Hey everyone, So I've been brewing about a year and a half, and this is the first time I've ran into this.

I brewed Northern Brewer's Cascade Mountains Imperial IPA. Fantastic Brew, I made it almost exactly a year ago, and it was amazing, so I decided to make it again.

Brew day: Jan 25th 2014
Primary Fermentation: Jan 25 - Feb 9 (Total of 15 days)

On brew day, my gravity was PERFECT, spot on at 1.085 (big beer). When I moved it to secondary however, I took a Refractometer reading, and it was sitting at 1.038!! WAY TOO HIGH, wtf.

Last time I brewed this beer, it bottomed out at 1.014. I did NOT make a yeast starter either time, I know it is recommended for big beers, but I haven't built my stir plate yet, and I figured, "meh, it worked fine without one last time".

Did my yeast drop out too soon? Or maybe they weren't able to metabolize everything? Or will the gravity continue to drop during the next 2 weeks in secondary?
NOTE: My Wyeast pack swelled up HUGE like a balloon, and Primary fermentation was INSANE, had to use the blow-off tube for the first 5 days, cuz it was so aggressive. So I thought it was doing well?
NOTE: Yes, my temps remained very stable. In a closet with a space heater, kept between 68-76 for pretty much the entire Primary.

Should I repitch? Or wait?? I was really looking forward to that approx. 9.45% ABV again, but I'm afraid I won't hit it. PLEASE GIVE ME SOME ADVICE.

 

[johnsnownw]

Your refractometer isn't accurate in the presence of alcohol. You need to take your measurements with a hydrometer for FG.

 

[stpug]

Using BeerSmith's Refractometer conversion tool:
OG 1.085
FG 9.9 Brix
Corrected FG 1.012 (~9.7% ABV)

Edit:
While some folks claim their refractometers are not accurate post-fermentation, I find that mine IS accurate. However, the issue of equipment and user readings does come into play.

 

[Zandrello]

Using BeerSmith's Refractometer conversion tool:
OG 1.085
FG 9.9 Brix
Corrected FG 1.012 (~9.7% ABV)

Edit:
While some folks claim their refractometers are not accurate post-fermentation, I find that mine IS accurate. However, the issue of equipment and user readings does come into play.

Wait, so are u saying I should take a Brix reading?? Or was BeerSmith compensating for the presence of alcohol??

 

[Zandrello]

Your refractometer isn't accurate in the presence of alcohol. You need to take your measurements with a hydrometer for FG.

My whole point of buying a refractometer, was to NOT have to use the annoying hydrometer anymore lol.....

 

[dobe12]

NOTE: Yes, my temps remained very stable. In a closet with a space heater, kept between 68-76 for pretty much the entire Primary.

By no means is "68-76" a stable temp. This has little to do with your issue, but I just wanted to clarify that. 68F fermentation temp (NOT ambient) is an ok temp, but 76F either ambient of fermentation temp is too high. And jumping up and down between those temps isn't good for you yeast or beer.

 

[dobe12]

But back to your original question. You should have pitched a lot more yeast than you did, so the yeast you pitched may have pooped out leaving an under attenuated beer. Even if that yeast was 100% viable (which of course it wasn't) you should have pitched close to 300 billion cells or 3 packs of yeast. If the yeast had some age to it, that number could easily rise to 4-5 packs of yeast.

Start making starters. A stir plate is nice, but not a must.

 

[BigFloyd]

My whole point of buying a refractometer, was to NOT have to use the annoying hydrometer anymore lol.....

No problem in using one, just be aware that the presence of alcohol throws the reading off (too high) and you have to use a correction calculator. For grins, I took a side-by-side hydro reading and refract reading on a beer that was finishing up. Hydro=1.017 vs. Refract (uncorrected)=1.035.

 

[stpug]

Wait, so are u saying I should take a Brix reading?? Or was BeerSmith compensating for the presence of alcohol??

Refractometers are scaled to read brix natively. Many have had an additional scale added for specific gravity. There are many indications that the specific gravity scale is not always correct to brix, particularly when dealing with malt sugars. Therefore, I choose to always record brix readings.

You obtained an OG of 1.085 which may or may not have been converted from brix. If it was then it was likely fairly close. If it was not (i.e. you read 1.085 in your refractometers dual-scale) then it was likely off by some amount. I'm assuming you're reading is correct, but please correct me if I'm wrong.

You then saw a FG reading of 1.038. I suspect this was read directly from the refractometer. When reading across the scale it corresponds to ~9.9 brix which is the value I used.

Plugging your OG 1.085 and your FB 9.9% into BeerSmith, it calculates an approximate FG of 1.012. HOWEVER, this is a highly temperamental reading and is subject to significant inaccuracy depending on how well you read the brix values as well as how well your refractometer "behaves". There are lots of factors that can throw off readings when using refractometers and is partly the reason why many folks cannot use one for FG determination; the least of which is the calculator actually used. Through dual-readings on many beers (refract and hydro), I have found BeerSmith to be the most reliable for me (Sean Terrill's was fairly inaccurate for me). I'm generally 0-1 point off from my hydro readings which is within my margin of error on readings a hydrometer anyway.

So, with all that said, what was your original brix reading?

 

[Zandrello]

By no means is "68-76" a stable temp. This has little to do with your issue, but I just wanted to clarify that. 68F fermentation temp (NOT ambient) is an ok temp, but 76F either ambient of fermentation temp is too high. And jumping up and down between those temps isn't good for you yeast or beer.

I should clarify, I meant that it never went outside those temps. But I was able to keep it around 72-74 most of the time. And for this recipe it is noted that 76 is not too high. The only time it got that high was during REALLY high Kreusen.

 

[Zandrello]

But back to your original question. You should have pitched a lot more yeast than you did, so the yeast you pitched may have pooped out leaving an under attenuated beer. Even if that yeast was 100% viable (which of course it wasn't) you should have pitched close to 300 billion cells or 3 packs of yeast. If the yeast had some age to it, that number could easily rise to 4-5 packs of yeast.

Start making starters. A stir plate is nice, but not a must.

Dobe, this does not explain why I had perfect OG and FG the first time I made the beer. I know a yeast starter would be "advisable", and preferred, but I found that it was not entirely necessary. Must have been really good yeast.

Thanks for the advice! I will take a Hydro and a refract reading before i move it to the Keg.

 

[Zandrello]

]

Start making starters. A stir plate is nice, but not a must.

I will definitely start doing so. I now have the magnet, and the other necessary parts, will probably build it this weekend!!

 

[Zandrello]

No problem in using one, just be aware that the presence of alcohol throws the reading off (too high) and you have to use a correction calculator. For grins, I took a side-by-side hydro reading and refract reading on a beer that was finishing up. Hydro=1.017 vs. Refract (uncorrected)=1.035.

Interesting, well that puts my mind at ease then. By using your example, that should mean my FG is pretty close to being on the ball. Around 1.017-18

My refract reading was about 1.038
I did not take a Brix reading, but I will start doing that in the future. It is a dual scale.

 

[dobe12]

I should clarify, I meant that it never went outside those temps. But I was able to keep it around 72-74 most of the time. And for this recipe it is noted that 76 is not too high. The only time it got that high was during REALLY high Kreusen.

What yeast strain? Unless you're using a Saison or certain Belgian yeast strains, which I'm sure that kit doesn't call for, mid to upper 70's is too high, IMO. You'll still make beer, but may have unwanted yeast by-products. For that beer and most ale styles you really want to keep the fermentation temps in the low to mid 60's. And remember actual fermentation temperatures are higher than ambient temps.

 

[Zandrello]

Refractometers are scaled to read brix natively. Many have had an additional scale added for specific gravity. There are many indications that the specific gravity scale is not always correct to brix, particularly when dealing with malt sugars. Therefore, I choose to always record brix readings.

You obtained an OG of 1.085 which may or may not have been converted from brix. If it was then it was likely fairly close. If it was not (i.e. you read 1.085 in your refractometers dual-scale) then it was likely off by some amount. I'm assuming you're reading is correct, but please correct me if I'm wrong.

You then saw a FG reading of 1.038. I suspect this was read directly from the refractometer. When reading across the scale it corresponds to ~9.9 brix which is the value I used.

Plugging your OG 1.085 and your FB 9.9% into BeerSmith, it calculates an approximate FG of 1.012. HOWEVER, this is a highly temperamental reading and is subject to significant inaccuracy depending on how well you read the brix values as well as how well your refractometer "behaves". There are lots of factors that can throw off readings when using refractometers and is partly the reason why many folks cannot use one for FG determination; the least of which is the calculator actually used. Through dual-readings on many beers (refract and hydro), I have found BeerSmith to be the most reliable for me (Sean Terrill's was fairly inaccurate for me). I'm generally 0-1 point off from my hydro readings which is within my margin of error on readings a hydrometer anyway.

So, with all that said, what was your original brix reading?

Mr Pug, thanks so much for all your info. Sadly, I did not take an ORIGINAL brix reading, it was my first time using my new refract toy at the time, and I didn't even think to take Brix reading, because I'm not used to that scale. I took the Specific Gravity reading cuz that's what I'm used to, and I'm good at ABV calculations using that scale. It's what I have the most experience with (since that is all I've ever used with a hydro).

I will start recording both though for sure. Just didn't think of it before. Glad I came here with my questions!

 

[dobe12]

Dobe, this does not explain why I had perfect OG and FG the first time I made the beer. I know a yeast starter would be "advisable", and preferred, but I found that it was not entirely necessary. Must have been really good yeast.

Thanks for the advice! I will take a Hydro and a refract reading before i move it to the Keg.

Every fermentation is different. You can brew the same beer 10 times and a few will taste a little different if you're not controlling fermentation temps, pitching amounts, etc.

 

[Zandrello]

What yeast strain? Unless you're using a Saison or certain Belgian yeast strains, which I'm sure that kit doesn't call for, mid to upper 70's is too high, IMO. You'll still make beer, but may have unwanted yeast by-products. For that beer and most ale styles you really want to keep the fermentation temps in the low to mid 60's. And remember actual fermentation temperatures are higher than ambient temps.

Wyeast 1272 is what comes with the recipe by default. Unless you opt for the dry yeast S-05, which I NEVER do. I prefer the liquid yeast, I've always had fantastic results.

Thanks for the info. If it makes you feel better, it has been sitting at about 64-66 degrees for the past 10 days or so.

 

[dobe12]

Wyeast 1272 is what comes with the recipe by default. Unless you opt for the dry yeast S-05, which I NEVER do. I prefer the liquid yeast, I've always had fantastic results.

Thanks for the info. If it makes you feel better, it has been sitting at about 64-66 degrees for the past 10 days or so.

Hey it's your beer. No skin off my back. Just trying to give you some tips. I use that yeast often. The upper range of temperature (noted by the manufacturer) is 72F, but I normally ferment around 60-64F.

Another tip if you care, temperature is only crucial for the first few days of fermentation where most esters are formed. After that it's not as big of a deal.

You should try brewing the same beer again, with the proper amount of yeast and fermented in the low to mid 60's. I bet you'd be surprised at the final product.



FWIW, many would agree proper pitching rates and temperature control are two of the biggest factors in making a great beer.

 

[Zandrello]

Hey it's your beer. No skin off my back. Just trying to give you some tips. I use that yeast often. The upper range of temperature (noted by the manufacturer) is 72F, but I normally ferment around 60-64F.

You should try brewing the same beer again, with the proper amount of yeast and fermented in the low to mid 60's. I bet you'd be surprised at the final product.



FWIW, many would agree proper pitching rates and temperature control are two of the biggest factors in making a great beer.

Interesting, I must have mis-read or gotten mistaken on the upper range for that yeast. I will say I'm glad that it rarely got upwards of 74. That's good I guess, when it did get up there, it didn't stay there for long. I was afraid it would get higher, so I typically would wrap a cold wet towel around the carboy, and turn the heater vent to that bedroom off for an hour or so... I will certainly brew this again and again, it's a FANTASTIC IPA, great recipe. Also, next time I will be doing it All-Grain, Finally got all my equipment

Next time I will certainly try the low to mid 60's. I'm always down to try new things. I just was always under the impression that Ales should start out between 68-74 because the yeast like being warm in the beginning?? What do you think?

 

[johnsnownw]

Next time I will certainly try the low to mid 60's. I'm always down to try new things. I just was always under the impression that Ales should start out between 68-74 because the yeast like being warm in the beginning?? What do you think?

Most ales should be below 68°, not ambient, but the wort should be below that temp.

 

[BigFloyd]

Next time I will certainly try the low to mid 60's. I'm always down to try new things. I just was always under the impression that Ales should start out between 68-74 because the yeast like being warm in the beginning?? What do you think?

Warmer temps do make the yeast cells more active, but that's not necessarily a good thing. If you pitch a sufficient amount of yeast into well-oxygenated wort, you don't have to (and should not) up the temp to promote yeast activity.

It's much better to start cool and finish warmer. For most of my ales, I pitch at 60-62*F, set the ferment temp on my controller to begin at 63-64*F, hold it there until activity begins to slow (usually 3-5 days) then begin to ramp it up to finish and clean up anywhere from 66-75*F depending in the strain (Belgians on the high end). If I'm using Nottingham, I'll pitch at 55*F and begin at 56-57*F for a very clean lager-like flavor profile in certain brews like an Altbier.

 

[dobe12]

It's much better to start cool and finish warmer. For most of my ales, I pitch at 60-62*F, set the ferment temp on my controller to begin at 63-64*F, hold it there until activity begins to slow (usually 3-5 days) then begin to ramp it up to finish and clean up anywhere from 66-75*F depending in the strain (Belgians on the high end). If I'm using Nottingham, I'll pitch at 55*F and begin at 56-57*F for a very clean lager-like flavor profile in certain brews like an Altbier.

This is great info and pretty much exactly what I do. Pitch and hold around 60-62F for a few days then raise the temp into the mid upper 60's for a few days, then pull the fermentor out of my mini-fridge and let it sit at room temps for the duration. For pale ales, IPAs, and many other ales, I prefer a clean fermentation where the yeast adds very little character to the beer.

Now for Belgians, Saisons, some English ales, and some others I like the yeast to shine so my process is much different.

 

[Zandrello]

This is great info and pretty much exactly what I do. Pitch and hold around 60-62F for a few days then raise the temp into the mid upper 60's for a few days, then pull the fermentor out of my mini-fridge and let it sit at room temps for the duration. For pale ales, IPAs, and many other ales, I prefer a clean fermentation where the yeast adds very little character to the beer.

Now for Belgians, Saisons, some English ales, and some others I like the yeast to shine so my process is much different.

This is all very great info. Thanks guys! I will certainly try this with my next brew. Have you learned this just based off experience or what?? I ask because, most of the Wyeast strains I have used say on the pack to pitch between 68-72. But you pitch around 60-62?? Seems so low! I was just always afraid that if it was that low, the ale yeast would "be lazy" and not do as much to ferment cuz they were too cool...?

I'm brewing a mini-mash clone of Tallgrass Buffalo Sweat this weekend, and will give this a try. Pitch around 60.

Furthermore, if I pitch and hold lower temps, it will make my life so much easier! I've been using a space heater in my fermentation closet to hold my temps ABOVE 68. But if I keep it down closer to 60-62, I won't even NEED the space heater! (It's really cold here in Oklahoma)

 

[dobe12]

This is all very great info. Thanks guys! I will certainly try this with my next brew. Have you learned this just based off experience or what?? I ask because, most of the Wyeast strains I have used say on the pack to pitch between 68-72. But you pitch around 60-62?? Seems so low! I was just always afraid that if it was that low, the ale yeast would "be lazy" and not do as much to ferment cuz they were too cool...?

I'm brewing a mini-mash clone of Tallgrass Buffalo Sweat this weekend, and will give this a try. Pitch around 60.

Furthermore, if I pitch and hold lower temps, it will make my life so much easier! I've been using a space heater in my fermentation closet to hold my temps ABOVE 68. But if I keep it down closer to 60-62, I won't even NEED the space heater! (It's really cold here in Oklahoma)

I initially learned from this and other forums, then through experience. Generally, fermenting on the cooler side will suppress yeast flavors and let the yeast ferment cleanly adding little flavor to the beer. But yeast strains are all different and all react differently to different temperatures. Fermenting warmer will encourage the yeast to produce more esters which contribute more flavors to the final product.

When I'm making a pale ale or IPA I really want the hops to shine. So, I ferment cooler to get a very clean, crisp profile allowing the hops and malt to come through and dominate the flavor.

When talking about wheat yeast, you'll get wildly different flavors if fermenting at 60F compared to 70F. Lower leans towards clove flavors and higher temps towards banana.

Belgians and Saison yeast strains will give off lots of strong esters at raised temps. I like to start my Belgians closer to 70F and raise them up after only a day or two to promote these flavors. For Saisons, I start even higher, in the low 70s and let the temperature climb up into the upper 70's and even 80s', again to encourage those esters.

IMO yeast is the backbone to a beer's flavor. You can manipulate a beer's flavor by choosing a specific yeast and controlling temperatures. Check out Wyeast's site for more specifics to each strain, but also understand the number they show for attenuation and temperature range are just averages. They are not hard numbers that can't be broken.

 

[strangr419]

I am a new BIAB brewer having done 3 to date after brewing with extract for a year and a half.
I took a FG in my latest red ale and the hydrometer read 1.022. This is the highest FG I've ever had. This is not a high gravity brew.
I've been reading this string and others and see that higher mash temp can somehow cause higher FG.
I recall that during the mash the temps were a bit high, at one point it got to 170 and we stirred the hell out of it to cool it and eventually got it down to 150-155.
Is my high FG potentially a result of the high mash temp? If so, can someone explain why this happens? What are the likely results to my final beer?
Just trying to learn something new to help avoid this in the future. Thank you everyone for a great forum.


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[strangr419]

Forgot to mention on my post above, I pitched two dry packs of US-05.

Thanks for your help!


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[mikeprooo]

Hi OP / All:

How did the batch come out? I'm curious because I have the same batch in my primary. I did everything according to instruction, and mine is 10 days in the primary and still has a nice level of krausen and bubbling away. I pitched a re-hydrated pack of the danstar west coast dry supplied with the kit ( US 97? ) plus I added a half pack of US - 05 that was in the fridge; it was a left over from a gal batch I did earlier. I have the basement bathroom as my "beer room" so I've kept my fermometer at around 62-64 as the carboy is in the tub with a small amount of water to keep things cool. I hope this will be my best batch yet!

Let me know your thoughts...

Mike

 

[BigFloyd]

Hi OP / All:

How did the batch come out? I'm curious because I have the same batch in my primary. I did everything according to instruction, and mine is 10 days in the primary and still has a nice level of krausen and bubbling away. I pitched a re-hydrated pack of the danstar west coast dry supplied with the kit ( US 97? ) plus I added a half pack of US - 05 that was in the fridge; it was a left over from a gal batch I did earlier. I have the basement bathroom as my "beer room" so I've kept my fermometer at around 62-64 as the carboy is in the tub with a small amount of water to keep things cool. I hope this will be my best batch yet!

Let me know your thoughts...

Mike

Sounds like a plan Mike.

Don't worry about mixing the two types of yeast. Those two are pretty similar anyway. Since it's been 10 days, I'd suggest moving it to somewhere a bit warmer (around 68-70*F) if you can to encourage a good clean up of by-products.

 

[mikeprooo]

Thanks!

Well thats easy, Ill lift the carboy out of the tub into the temp controlled area of the basement bathroom, via my space heater..easy to keep it around 68 - 70!