What is causing my FG to be 1039?

[Belgian Samurai]

I couldn't help but notice that the pre-sugar addition reported OG of 1.073 seemed awfully high for the grain bill, even in my non-native-metric-estimating brain. So I ran some numbers.

18.93 liters
0.43 kg White Wheat Malt
0.43 kg - Pale Malt (2 Row) US
2.35 kg - Wheat Dry Extract

Even at 100% mash efficiency for the malts (which of course is impossible), this would only come out to about 1.060. At a more reasonable 75% mash efficiency, we're looking at about 1.056.

So...something is off about the OG reading, or the stated recipe, or my reading comprehension. My guess would be that the reading was taken from a sample that hadn't been thoroughly mixed with the top off water.

Oh, man, I cannot remember if I took that OG before the top-off water or not. It's not mentioned in my notes.

 

[BrewnWKopperKat]

This seems awfully quick for me given my experience w/ a Tripel last March.

What strain of yeast did you use?

 

[VikeMan]

Oh, man, I cannot remember if I took that OG before the top-off water or not. It's not mentioned in my notes.

Well, even if you take it after topping off (which you should), you have to make sure it's very thoroughly mixed. Not mixing thoroughly after topping off is probably the most common gravity measurement mistake with partial boil batches.

Fortunately, most of your gravity came from extract, so mash efficiency has less effect than it typically does, and the expected gravity is more predictable. I would go ahead and assume an OG of 1.056 (pre-sugar) and you won't be far off.

 

[Belgian Samurai]

This week, I will study/learn about brix and calculators. Thanks, everyone!

Likewise I checked with the refractomer calculator on Brewer's Friend to come up w/ these numbers using his 1.073 OG. His FG (1.037) converted with alcohol present was 1.017 w/ approx 7.39% ABV and ~ 76% attenuation. So overall not bad @ 2 days fermentation. This seems awfully quick for me given my experience w/ a Tripel last March. Wonder what his fermentation temperature was? I have since gone to using the Tilt for monitoring and to get the other relevant temperature data.

I was pressure fermenting in a keg with temps in the 20Cs/70Fs. For that, I did use a CO2/PSI calculator.

 

[bike2brew]

I converted his base grains to extract and totaled w/ the WDE to get 4kg DME. Used in a 19 liter batch, the est OG is 1.079 and w/ 75% attenuation the predicted FG is 1.022. So again, coming into the ballpark. I suspect as everyone else has pointed out previously the OP has just not accounted for the alcohol presence in his readings.

I do have plans for another Tripel soon and will monitor the fermentation progress better next time.

I love these calculators and the telemetry for reducing the guess work. However, I have other very capable brewing friends that still enjoy a black magic approach.

 

[hotbeer]

Most everything for measuring efficiency for mash and beer fermentation revolves around specific gravity. Refractometers require more effort to get a approximation of specific gravity. And as evidenced in many threads here can cause quite a long and confusing discussion.

So just get a hydrometer and use it to double check your results with the refractometer. Then you'll know quickly if you are calculating correction factors incorrectly. After you know you are getting the same numbers, you can exclusively use your refractometer.

Hydrometers are very inexpensive.

 

[VikeMan]

I converted his base grains to extract and totaled w/ the WDE to get 4kg DME. Used in a 19 liter batch, the est OG is 1.079 and w/ 75% attenuation the predicted FG is 1.022.

I assume you included the sugar in this calculation, because otherwise:

Roughly speaking, a kg of malt at 75% efficiency = ~ 0.6 kg of DME (or WME).

0.86 kg Malt + 2.35 kg Extract =
(0.86 kg Malt x (0.6 Extract/Malt)) + 2.35 kg Extract =
= ~2.9 kg Extract

 

[AlexKay]

At this point, I'd throw up my hands and call the recording (for learning and reproducibility) aspect of this particular batch a loss. Then the only remaining question is whether it tastes good. Does it taste good?

 

[bike2brew]

What strain of yeast did you use?

It was a Brewer's best kit and the yeast was unspecified. Checking my notes, it went from 1.076 to 1.01 in 7 days so quicker than I thought I remembered.

 

[bike2brew]

I assume you included the sugar in this calculation, because otherwise:

Roughly speaking, a kg of malt at 75% efficiency = ~ 0.6 kg of DME (or WME).

0.86 kg Malt + 2.35 kg Extract =
(0.86 kg Malt x (0.6 Extract/Malt)) + 2.35 kg Extract =
= ~2.9 kg Extract

 

[bike2brew]

Yes, the sugar was included to bring the total DME up to 3.98 or 4.

 

[bike2brew]

Most everything for measuring efficiency for mash and beer fermentation revolves around specific gravity. Refractometers require more effort to get a approximation of specific gravity. And as evidenced in many threads here can cause quite a long and confusing discussion.

So just get a hydrometer and use it to double check your results with the refractometer. Then you'll know quickly if you are calculating correction factors incorrectly. After you know you are getting the same numbers, you can exclusively use your refractometer.

Hydrometers are very inexpensive.

I used a hydrometer initially and checked gravity weekly. The switch to a refractometer made for more economic sampling and figured out how to use the calculator so no real confusion on my end.

 

[BrewnWKopperKat]

It was a Brewer's best kit and the yeast was unspecified.

Fermentis, in their Tips and Tricks brochure (p 28) provides some performance information on their strains. From that information, it looks like S-33 can be 'done' fairly quickly while US-05 can take more time.

There are many factors (wort composition, fermentation temperature) that affect performance. For example, I've fermented with US-05 in the 58-62F range a couple of times. I found it to be very, very slow.

 

[bike2brew]

Yes, most of my experience is w/ us 05. I have some s 33 set aside for the next tripel. Let time I learned but did not apply the lesson about fermenting at higher temperature to obtain the characteristic flavors. I kept everything low so the beer was more phenolic. Appeals to some but not what I was looking for.

Fermentis, in their Tips and Tricks brochure (p 28) provides some performance information on their strains. From that information, it looks like S-33 can be 'done' fairly quickly while US-05 can take more time.

There are many factors (wort composition, fermentation temperature) that affect performance. For example, I've fermented with US-05 in the 58-62F range a couple of times. I found it to be very, very slow.

 

[SRJHops]

Not sure if this was covered, but what did the recipe calculator predict for the FG? From my view, with such a high OG and so little yeast pitched, that FG does not seem totally unreasonable, combined with some other factors.

I would have pitched two packs of yeast at least, and probably some liquid too for good measure! It's nearly impossible for homebrewers to overpitch, but I believe many are seriously under pitching.

 

[DBhomebrew]

From my view, with such a high OG and so little yeast pitched, that FG does not seem totally unreasonable

To which OG and which FG are you referring?

 

[SRJHops]

To which OG and which FG are you referring?

I was using the original numbers from the OP.
I'm not sure if we ever got the final corrected numbers? I did see that someone calculated predicted FG of 1.022, which is in the ballpark of 1.039 if a few procedures were off.... And not enough yeast pitched to do the trick...

 

[DBhomebrew]

I was using the original numbers from the OP.

Those were found to be erroneous. OP had not used a refractometer calculator to arrive at FG. OP is also unsure of their measured OG. Given the grist is predominantly extract and sugar, low 1070s is likely.

FG of 1.022, which is in the ballpark of 1.039

That's a stretch.

 

[VikeMan]

OG (including sugar) seems like it was probably about 1.074-ish.

1.074 --> 1.039 = ~47% ADF
1.074 --> 1.022 = ~70% ADF

Not really in the same ballpark. Underpitching can certainly cause lower attenuation, but the affect is usually pretty subtle. Pitch rate (within reason) just isn't a major driver of attenuation in my experience. (That said, there are other reasons to pay attention to pitch rate.)

Also, I think even 70% ADF would be low for this wort and yeast. We don't know the mash temp or length, but with a subtantial amount of the OG coming from table sugar, this should be very fermentable wort.

 

[SRJHops]

Those were found to be erroneous. OP had not used a refractometer calculator to arrive at FG. OP is also unsure of their measured OG. Given the grist is predominantly extract and sugar, low 1070s is likely.



That's a stretch.

He had 1.073 for OG. Was there a final predicted FG or corrected measurement?

Yeah, bit of a stretch, but there are certainly factors that could have caused it. If I missed by that much I'd pitch more yeast...

 

[DBhomebrew]

He had 1.073 for OG. Was there a final predicted FG or corrected measurement?

That OG in Post #1 didn't include 2# of sugar. Yes, ~1.022.

If I missed by that much I'd pitch more yeast..

But, they didn't.

 

[SRJHops]

OG (including sugar) seems like it was probably about 1.074-ish.

1.074 --> 1.039 = ~47% ADF
1.074 --> 1.022 = ~70% ADF

Not really in the same ballpark. Underpitching can certainly cause lower attenuation, but the affect is usually pretty subtle. Pitch rate (within reason) just isn't a major driver of attenuation in my experience. (That said, there are other reasons to pay attention to pitch rate.)

Also, I think even 70% ADF would be low for this wort and yeast. We don't know the mash temp or length, but with a subtantial amount of the OG coming from table sugar, this should be very fermentable wort.

Agree, it should be very fermentable.

Once I started using the proper pitch rates and above (i.e. not what the yeast manufacturer recommends), my beers got a ton better. Seems simple in retrospect, but I was using one packet of yeast for years before I figured it out.

I threw three packets of yeast at my very first Saison two years ago, and entered it in my very first competition. It took first - and I've never looked back. Almost all of my beers get 2-3 packs of yeast, usually a blend. Other folks use starters of course... but I do think a lot of home brewers are not using enough yeast...

 

[SRJHops]

That OG in Post #1 didn't include 2# of sugar. Yes, ~1.022.




But, they didn't.

Ah, I missed that final FG. 1.022 seems more reasonable, though with that much sugar I might have guessed lower. When I use two pounds of sugar my Belgian beers sometimes finish under 1.000!

 

[BrewnWKopperKat]

When I use two pounds of sugar my Belgian beers sometimes finish under 1.000!

Wort composition and yeast selection.

OPs recipe is roughy 60% DME, 25% sugar, and 15% mashed malts (based on gravity points supplied, not weight). Even with the 25% sugar, this is not a highly fermentable wort.

Look at the chart in #23.

S-33 is going to leave a lot of "stuff" behind that other strains (e.g. BE-134, BE-256) wont't.

 

[SRJHops]

Wort composition and yeast selection.

OPs recipe is roughy 60% DME, 25% sugar, and 15% mashed malts (based on gravity points supplied, not weight). Even with the 25% sugar, this is not a highly fermentable wort.

Look at the chart in #23.

S-33 is going to leave a lot of "stuff" behind that other strains (e.g. BE-134, BE-256) wont't.

True, that. I often use BE-134 and it eats everything!

I can't remember if he posted his mash temp, but that sure seems like a nicely fermentable wort to me? The sugar alone is going to drive some fermentation, and I'd think the DME will ferment nicely?

 

[BrewnWKopperKat]

I'd think the DME will ferment nicely?

My experiences with S-33 and DME from a couple of years ago indicate otherwise (70%-ish attenuation). Ingredients can change over time, but with a number of newer dry strains available, I haven't 'made time' to revisit S-33.

 

[SRJHops]

My experiences with S-33 and DME from a couple of years ago indicate otherwise (70%-ish attenuation). Ingredients can change over time, but with a number of newer dry strains available, I haven't 'made time' to revisit S-33.

Oh, I see what you mean. 70% isn't all that great, though I bet a lot of strains are around there. I think that's actually about what the OP got, so it seems his recipe likely worked fine after figuring out the measurements.

 

[VikeMan]

If we assume 70% ADF for the gravity contributed by the DME and the Malts, and 122% for the sugar (which was 25% of the gravity)...

(.75 x .70) + (.25 x 1.22) = .525 + .305 = ~83% ADF

 

[BrewnWKopperKat]

though I bet a lot of strains are around there.

FWIW, p 32 of Fermentis Tips & Tricks has a summary for their strains:

 

[SRJHops]

FWIW, p 32 of Fermentis Tips & Tricks has a summary for their strains:

View attachment 782898

I had to look up that HA 18. What a beast! I wonder if it works for high ABV Belgians?