SG issues

[Nberry]

The last few batches I have brewed, am having an issue with the SG dropping while it's in fermentation. I brewed a batch this weekend and the SG is 1.043 and when I got ready to add my yeast it was 1.040. It is now about 48 hours later, and the Tilt hydrometer is telling me that the SG in 1.017. I don't know if its correct as I don't want to open the container until I am ready to keg it. I expect it to drop, as it always does when I brew a batch, but this seems excessive. I have kept a spreadsheet of most of the beer that I have brewed, and they have lower SG readings at the end. I am needing to know if this is normal or am I doing something that is causing the large drop in SG readings from the time I start the fermentation? here is an example of an Irish Red Ale that I did a few years ago, SG after brewing is 1.042, SG reading after 1st fermentation is 1.020 and the final SG reading is 1.015 at the time of bottling. The recipe stated the OG is 1.042. It is possible, that I don't have a good understanding of these readings so any input would help to try and get a grasp of the situation to see if I need to change something or its just my lack of understanding.

 

[Minbari]

Are all these reading coming from the tilt? these things are not super accurate, but do a good job with trending.

A 0.03 drop is not uncommon if it cooled. temp effects the tilt to some degree

 

[Sandy Feet]

At bottling it is FG. SG is pre-fermentation. It is supposed to drop or you don't have any alcohol. Gravity readings with alcohol are lower than without. That is how you know the alcohol level.

 

[Minbari]

At bottling it is FG. SG is pre-fermentation. It is supposed to drop or you don't have any alcohol. Gravity readings with alcohol are lower than without. That is how you know the alcohol level.

Sg = specific gravity. it doesn't occur at any particular time

 

[Semper Sitientum]

Maybe there’s some confusion with the nomenclature. The “SG” immediately after brewing is the “OG” as stated in the second to last sentence of your post. And, as mentioned will go down with fermentation. Unless I’m misunderstanding.

 

[Zambi]

Seems a quick drop in SG, but not uncommon.
What yeast are you using and at what temperature?
(Kveik Voss can finish in less than 24 hours at high temps)

 

[J A]

The last few batches I have brewed, am having an issue with the SG dropping while it's in fermentation. I brewed a batch this weekend and the SG is 1.043 and when I got ready to add my yeast it was 1.040. It is now about 48 hours later, and the Tilt hydrometer is telling me that the SG in 1.017. I don't know if its correct as I don't want to open the container until I am ready to keg it. I expect it to drop, as it always does when I brew a batch, but this seems excessive. I have kept a spreadsheet of most of the beer that I have brewed, and they have lower SG readings at the end. I am needing to know if this is normal or am I doing something that is causing the large drop in SG readings from the time I start the fermentation? here is an example of an Irish Red Ale that I did a few years ago, SG after brewing is 1.042, SG reading after 1st fermentation is 1.020 and the final SG reading is 1.015 at the time of bottling. The recipe stated the OG is 1.042. It is possible, that I don't have a good understanding of these readings so any input would help to try and get a grasp of the situation to see if I need to change something or its just my lack of understanding.

Check the recipe numbers against the gravity readings that you're getting. The numbers are targets that you should be getting close to during the process.

OG, original gravity, on most beers is between 1.040 and 1.060, depending on the amount of fermentables that go into the recipe and mashing efficiency if you're brewing all grain.

FG, final gravity, is the reading after fermentation is finished and should be between around 1.010 and 1.015 or so for most beer styles, depending on Attenuation - percentage of the available sugars that are converted to alcohol.

ABV, alcohol content, is a calculation based on the difference in the two readings.

SG, as Minbari pointed out is specific gravity, a number that applies to any liquid as measured by a hydrometer (water equals 1.00)

Tilt numbers may or may not accurately match actual gravity at any particular time and should be confirmed with hydrometer readings.

 

[Dave Y]

I brewed a batch this weekend and the SG is 1.043 and when I got ready to add my yeast it was 1.040. It is now about 48 hours later, and the Tilt hydrometer is telling me that the SG in 1.017. I don't know if its correct as I don't want to open the container until I am ready to keg it. I expect it to drop, as it always does when I brew a batch, but this seems excessive. I have kept a spreadsheet of most of the beer that I have brewed, and they have lower SG readings at the end. I am needing to know if this is normal or am I doing something that is causing the large drop in SG readings from the time I start the fermentation?

Some points of clarification, if you will. I think I get your gravity readings, not withstanding the terminology discussion - which is correct.

what beer type/style did you brew?
Are you putting the tilt in the fermenter and then immediately pitching the yeast, or very soon after ?
Are you using liquid yeast, and / or a yeast starter culture and what strain of yeast?
what kind of fermenter are you using?
do you have temperature control?
what temperature are you fermenting at?

@Zambi is right; a warm or hot fermented Kveik yeast strain will completely finish in around 24-36 hours. My personal best is a 7%abv Voss Kveik fermented IPA that finished completely in 32 hours. Other yeast strains can also produce some ... vigorous... fermentations. Farmhouse, German wheat beer strains, etc. and the temperature they ferment at can have a profound effect on how fast they finish.

You’re not brewing a particularly big beer so in 48 hours from 1.040, 1.020 is pretty reasonable and I’d expect it to slow down from here. What about the airlock activity, how often is the airlock bubbling vs. the day before?

As to the tilt reading, the last thing I do before dropping the Tilt into the wort is wash it off thoroughly with hot tap water. My kettle temperature may read 75F, and I will transfer the wort to the fermenter, drop in the tilt and it will read something high like 85F and will settle into and adjust its temperature readings over the course of about 5 minutes. Sometimes I will see a gravity change as well but I monitor the gravity throughout with a refractometer and it’s consistently within ~ 0.003 of the tilt, which is for all practical purposes equal to my old school hydrometer. So, at the end of a boil, my refractometer will read, say, 1.054. Tilt and old school hydrometer will read about 1.051 - 1.053.
There is always an adjustment period after the Tilt is put into the wort. It can also be affected by a vigorous fermentation, with gravity bouncing around a bit.

My main fermenter has a cooling coil, and the tilt can get caught by it. rocking the fermenter frees it.

 

[Nberry]

Maybe there’s some confusion with the nomenclature. The “SG” immediately after brewing is the “OG” as stated in the second to last sentence of your post. And, as mentioned will go down with fermentation. Unless I’m misunderstanding.

I admit there is confusion and its my understanding of what everything means. Based on the replies, my brews are doing what they are supposed to its just my lack of understanding. Thank you for your response.

 

[Nberry]

Some points of clarification, if you will. I think I get your gravity readings, not withstanding the terminology discussion - which is correct.

what beer type/style did you brew?
Are you putting the tilt in the fermenter and then immediately pitching the yeast, or very soon after ?
Are you using liquid yeast, and / or a yeast starter culture and what strain of yeast?
what kind of fermenter are you using?
do you have temperature control?
what temperature are you fermenting at?

@Zambi is right; a warm or hot fermented Kveik yeast strain will completely finish in around 24-36 hours. My personal best is a 7%abv Voss Kveik fermented IPA that finished completely in 32 hours. Other yeast strains can also produce some ... vigorous... fermentations. Farmhouse, German wheat beer strains, etc. and the temperature they ferment at can have a profound effect on how fast they finish.

You’re not brewing a particularly big beer so in 48 hours from 1.040, 1.020 is pretty reasonable and I’d expect it to slow down from here. What about the airlock activity, how often is the airlock bubbling vs. the day before?

As to the tilt reading, the last thing I do before dropping the Tilt into the wort is wash it off thoroughly with hot tap water. My kettle temperature may read 75F, and I will transfer the wort to the fermenter, drop in the tilt and it will read something high like 85F and will settle into and adjust its temperature readings over the course of about 5 minutes. Sometimes I will see a gravity change as well but I monitor the gravity throughout with a refractometer and it’s consistently within ~ 0.003 of the tilt, which is for all practical purposes equal to my old school hydrometer. So, at the end of a boil, my refractometer will read, say, 1.054. Tilt and old school hydrometer will read about 1.051 - 1.053.
There is always an adjustment period after the Tilt is put into the wort. It can also be affected by a vigorous fermentation, with gravity bouncing around a bit.

My main fermenter has a cooling coil, and the tilt can get caught by it. rocking the fermenter frees it.

Wow! that is quite the response. I believe the issue is just my lack of understanding how the terms apply to the different numbers. Based on the responses I have received; my brews are okay it's just the brewer who needs to get a better understanding. the brews I have done, and it shows them to be fairly consistent.

 

[Dave Y]

Wow! that is quite the response. I believe the issue is just my lack of understanding how the terms apply to the different numbers. Based on the responses I have received; my brews are okay it's just the brewer who needs to get a better understanding. the brews I have done, and it shows them to be fairly consistent.

Ok, hopefully it all turns out well.
A good friend of mine was doing a brew with me, an IPA with a lot of hops and an aggressive hop schedule. At one point during the chaos of “what hop is next” he quips:

‘Dave; humans have been brewing beer for thousands of years. It’s unlikely we’re going to find a new way to screw it up'