Struggling with OGs, FGs, and ABVs

[Mike at Bay]

Gang, I am back into brewing after a short hiatus and looking to improve my outputs. FYI, I use mostly extract kits from Northern Brewer with Dry yeast, Huge build kettle but normally boil with 3-4 gallons, copper coil wort chiller, I clean and sanitize ALOT, ferment in sealed buckets, use Tilt BT hydrometers, ferment in temp controlled environment and keg the beer upon completion.

I routinely miss the OG, FG and ABV expectations contained in the recipes. For example, 2 beers almost done fermenting. Dry Irish Stout-- Recipe predicted OG of .042 with an ABV of around 4.2%....my result....OG of .034 and an ABV of around 3.41%. Chinook IPA -- Recipe predicted OG of .053 with an ABV of around 5.3%....my result...OG of .051 (good) but FG is .018 getting me to an ABV of 43.%.

I realize there are too many variables to know for sure what is wrong but....

Should I try liquid yeast? It seems more difficult to manage.
Am I not getting the right about of sugars to start? How could that be with NB extracts in their recipes?
Are Tilts inaccurate? I have tested against a regular glass hydrometer and it seems accurate within reasonable tolerance.

Thanks for any thoughts

 

[Bigbre04]

Gang, I am back into brewing after a short hiatus and looking to improve my outputs. FYI, I use mostly extract kits from Northern Brewer with Dry yeast, Huge build kettle but normally boil with 3-4 gallons, copper coil wort chiller, I clean and sanitize ALOT, ferment in sealed buckets, use Tilt BT hydrometers, ferment in temp controlled environment and keg the beer upon completion.

I routinely miss the OG, FG and ABV expectations contained in the recipes. For example, 2 beers almost done fermenting. Dry Irish Stout-- Recipe predicted OG of .042 with an ABV of around 4.2%....my result....OG of .034 and an ABV of around 3.41%. Chinook IPA -- Recipe predicted OG of .053 with an ABV of around 5.3%....my result...OG of .051 (good) but FG is .018 getting me to an ABV of 43.%.

how long did you leave it to finish up?

I realize there are too many variables to know for sure what is wrong but....

Stick with it, take detailed notes of times, temps, volumes, etc.

Should I try liquid yeast? It seems more difficult to manage.

Nope dry yeast is good. Dont do a starter

Am I not getting the right about of sugars to start?

No idea, big thing is the starting volume vs your post boil volume.

How could that be with NB extracts in their recipes?

No idea

Are Tilts inaccurate? I have tested against a regular glass hydrometer and it seems accurate within reasonable tolerance.

cant comment. i use temp calibrated hydrometers.

Thanks for any thoughts

I would consider adding a yeast nutrient.

What temp are you knocking out at? Be careful with the temp that you pitch your yeast.

Over pitching your yeast is a safe investment.

Is your yeast expired?

Be sure that you are using a "leave in" sanitizer like PAA or Star san.

Temp control is important. if it gets too hot/cold you will get off flavors and might stall out.

 

[Limey]

When I first started home brewing I used extract kits. I did not own (nor do I know if it was available) the equipment I have now so I did full boils with a copper coil chiller. Some kits were a "partial" extract that added some grains in a bag. I measured gravity with a hydrometer and fermented in a bucket. I NEVER hit the kit O.G. number either! It is only since going to all-grain brewing (Anvil Foundry 10.5) that I have been able to adjust my recipes, and methods and get pretty close to my expected gravity readings. A two-week ferment went a LONG way to getting the predicted ABV numbers! Keep at it - the way I look at it, you are brewing your OWN beer - if you want Bud, or Sam Adams - go and buy it! Once you get used to how it works, and stop worrying about reaching the claimed numbers, you'll find it's a lot more fun! In the end, just enjoy your beer!

 

[BarbarianBrewer]

Welcome back!

A common problem with measuring gravity with extract kits is not thoroughly mixing the water and the extract. This can lead to stratification, so some spots will be a little higher in gravity and other spots a little lower. I would suggest, taking multiple samples from different spots in the kettle to see if this is the problem.

Huge build kettle but normally boil with 3-4 gallons,

The other, more likely, issue is adding too much water. How are you measuring the water? If you are using a the measurement markings on a kettle or bucket, those markings may not be accurate. If you have a larger measuring cup (i.e. 2 quarts), use that to add the water and see how that matches up to the kettle/bucket markings.

Should I try liquid yeast? It seems more difficult to manage.
Am I not getting the right about of sugars to start? How could that be with NB extracts in their recipes?
Are Tilts inaccurate? I have tested against a regular glass hydrometer and it seems accurate within reasonable tolerance.

Liquid vs dry yeast wouldn't help. Both are good options.
I'm sure you can trust the OG from a Northern Brewer kit.
Tilts are accurate at the beginning of fermentation. However, during fermentation, kreuzen on top of it and CO2 bubbles on the side can skew the readings. I always use a hydrometer before and after fermentation.

 

[Dave Y]

Nope dry yeast is good. Dont do a starter

#Beefin'

There is an axiom in the motorsports world; "Horsepower forgives a multitude of sins". Do we know how old that yeast was and how it was stored?
Chances are, it's been sitting on a shelf for a while and not at ideal temperatures, so dry or not, a starter won't hurt. Is it necessary all the time? No, but when you have a variable like this with the high FG, I'd say you want yeast strong like Popeye, not wimpy like Olive Oyl... or you want your yeast to perform more like a supercar, less like a prius.

You could double pitch, though the beers you mentioned, you are well within tolerance.
What water are you using? If you're using tap water, what does your water report say?

You DID get a water analysis done like your business associate Marcellus Wallace asked you to, right?

I struggled with FG when using urban tap water. Too many chemicals to 'fix' the water. Yeast didn't like it.

Should I try liquid yeast? It seems more difficult to manage.

Not until you have the FG issue resolved.

Are Tilts inaccurate? I have tested against a regular glass hydrometer and it seems accurate within reasonable tolerance.

Tilts are plenty accurate, until or unless they get caked with yeast and even then they're surprisingly close. They also can get bounced around in a vigorous fermentation. For your context, they're fine.

Even though you're doing extract brewing, check out this thread: https://www.brewersfriend.com/forum/threads/all-in-one-brewhouse-help-thread.17832/

The instructions that come with your extract kit are analogous to the Pirate Code; More like guidelines than actual rules.
You have a set amount of malt extract, hops and yeast. The variable affecting OG is your water volume. Too much and you thin out the wort, you boil a set amount of time and miss the target gravity.
- what is your boil off rate? Knowing this helps remove another variable.
- if you have too much water for the boil off rate of your system, you can boil -BEFORE- the hop schedule to increase the gravity. Or you could add more LME/DME.

 

[Minbari]

I will just repeat my mantra. "Brew to gravity, not volume"

If you are high on gravity, add water. If you are low, boil more or start with less water than you need. If you end up with 5.25 gal or 4.5 gal, but the gravity is correct, it will make the rest of the process easier.

As for derivations in FG. There are allot. Mash temp, yeast type (% attenuation), yeast health, fermentation temp control. Fermentability (tied in some part to mash temp). To some extent, it is just trial and error and you will figure out your setup

 

[Craigerrr]

I would start at the beginning, if you are not hitting your expected OG there is one of two problems. Too much water, or the kit is shy on the malt extract required.

The solution here is to be more accurate measuring the water. Don't trust gradients on a kettle. For ultimate accuracy weigh the water. Water volume changes with temperature, but the weight does not. 1 pound of water is one pound of water regardless of it being 33F or 211F. You could just mix the malt extract into a lesser volume of water, then add water until the gravity gets down to where it is supposed to be, but you will never k ow what the issue is.

If you confirm with correctly measuring the water needed that your OG is still low, have some extra DME on hand to bring the OG up to where it should be. There are calculators to know how much to add to get from A to B with volume of X.

Once you get the OG sorted the FG problem should solve itself, as long as you are using the yeast that the recipe calls for. But definitely sort out the OG problem first.

 

[Sandy Feet]

I use spring water. Since it is in a one gallon container, I know how many gallons I have. Check your efficiency settings in the software, they may be set too high. That is why you take notes, so you can go back and dial in the software.
FG could very likely be a result of a high mash temperature.
You don't need to try liquid yeast until you are ready. Liquid yeast has a LOT more variety for different recipes, but get the basic yeasts to work first. If you pitch heavy enough with healthy yeast, you do not need a starter. Dry yeast works fine.
I did have a difficult time getting gravity to come out correctly when I did extracts on the stove. Now that I have a Hellfire burner outside where I can get a good mash temperature reading, and I use grain, things are a little more predictable except with French Saison yeast. The guys at the brew store usually give me a double crush for my BIAB.

 

[Minbari]

I would start at the beginning, if you are not hitting your expected OG there is one of two problems. Too much water, or the kit is shy on the malt extract required.

The solution here is to be more accurate measuring the water. Don't trust gradients on a kettle. For ultimate accuracy weigh the water. Water volume changes with temperature, but the weight does not. 1 pound of water is one pound of water regardless of it being 33F or 211F. You could just mix the malt extract into a lesser volume of water, then add water until the gravity gets down to where it is supposed to be, but you will never k ow what the issue is.

If you confirm with correctly measuring the water needed that your OG is still low, have some extra DME on hand to bring the OG up to where it should be. There are calculators to know how much to add to get from A to B with volume of X.

Once you get the OG sorted the FG problem should solve itself, as long as you are using the yeast that the recipe calls for. But definitely sort out the OG problem first.

1 pound is 1 pound. But 1 pound at 32F is not the same volume as 200F

 

[Zambi]

My first guess would have been the use of a refractometer, but you mention you use a hydrometer or tilt.
I would definitely check the tilt reading against a simple hydrometer.

other things to look at:
Fermentation temperature
Yeast expiry date (although I have used yeast more than 2 years past without issues)
Pitch temperature
Volume of water
Time - you don't mention how long you ferment
Dunno... (Never done an extract kit )

Mixing properly before measuring SG, as mentioned in the posts above, can be a factor as well

Maybe try inputting the ingredients in the calculators here and see what it comes up with

 

[Mike at Bay]

Gang Thanks so much for all of the comments and recommendations. I will attempt to address most comments here:
1) Thanks...sticking with dry yeast for now. I might dabble in starters and heavier pitch for the higher gravity beers. Liquid yeast after I get more consistent.
2) Fermentation time varies both due to the yeast working and due to my life schedule but I always wait to move on until the FG remains the same for a number of days so never less than 10 days.
2) Water, Water, Water......sounds like I have been a little sloppy both in terms of using tap not knowing the make of or the water (BTW I live on an island in N Florida so the water ain't great.) and the measurement. Literally never occurred to me to not use the markings on the kettle.
3) I don't know my boil off rate per se. I use a 10 gallon pot and a propane burner outside. Throws a lot of heat and thus a lot of steam (I do use the lid ). I use a Thermapen to keep track of temps.
4) I have not used a calculator software in the past but I will begin to do so to track my outcomes.
5) I have BIAB and have done that in my accent past with some success. After making sure my equipment and water are good and getting the software I may try that again as I always question whether I am getting all enough out of the container.

Thanks again for the support. I will take the recommendations and report back. Starting with the water.

 

[Dave Y]

Awesome @Mike at Bay

WRT water, you can buy spring water as mentioned above, or go full on reverse osmosis and add chemicals or somewhere in between. I suggest a boil off test before the next brew. it's really easy.

put as much water in your kettle as you would typically have with water and extract, etc. Start the boil from where you typically start temperature wise.
At 60 minutes exactly, terminate the boil. let it cool enough to settle and gauge how much water is in the kettle. Do some brewer's math and you have your 'boil off rate'. <amateur tip> if you go electric, do not believe the numbers in the manual if they quote a boil off rate. <amateur tip>
My anvil 10.5 is alleged to boil off a gallon in an hour at 110v - it's more like .6 gallons.
My anvil 18 boils off 1.7 gallons in one hour.

So, now you know your boil off rate. You can use tap water for this

Next up, if you don't have a refractometer, get one. During the mash, you can measure the gravity of your wort with it. Or, for extract brewing, after you mix in the LME/DME, you get a reading and see if you have the gravity you need. No? Easy, go grab a bag of light DME, add some in, mix, take another reading. Wash, rinse, repeat.

keep some DME on hand, not just for the brew but if you do continue to struggle to reach FG, you can do a yeast starter. You can do this on the cheap, but I got a kit - beaker, stir plate and all. Mostly to channel my inner Walter White. Anyway, you pitch the yeast into water and your yeast, typically about 1.5L
Let the yeast multiply for several hours Kveik yeast works much faster, but generally just before bed to about 2PM is good-ish. You don't want the starter to finish fermenting the yeast, just multiply the cells to optimum, then pitch into the yeast. This will cost you about .003 - .005 gravity points, unless you cold crash the yeast a day or so and then dump the excess liquid. You then put a small amount of wort in, agitate & pitch that into your wort.
The resulting yeast will be MUCH stronger. We're talking 12 days pitch to cold crash on a Pilsner for just a straight pitch vs. 5 days pitch to cold crash on the same mash bill.

Let us know how it goes !

 

[Minbari]

Gang Thanks so much for all of the comments and recommendations. I will attempt to address most comments here:
1) Thanks...sticking with dry yeast for now. I might dabble in starters and heavier pitch for the higher gravity beers. Liquid yeast after I get more consistent.
2) Fermentation time varies both due to the yeast working and due to my life schedule but I always wait to move on until the FG remains the same for a number of days so never less than 10 days.
2) Water, Water, Water......sounds like I have been a little sloppy both in terms of using tap not knowing the make of or the water (BTW I live on an island in N Florida so the water ain't great.) and the measurement. Literally never occurred to me to not use the markings on the kettle.
3) I don't know my boil off rate per se. I use a 10 gallon pot and a propane burner outside. Throws a lot of heat and thus a lot of steam (I do use the lid ). I use a Thermapen to keep track of temps.
4) I have not used a calculator software in the past but I will begin to do so to track my outcomes.
5) I have BIAB and have done that in my accent past with some success. After making sure my equipment and water are good and getting the software I may try that again as I always question whether I am getting all enough out of the container.

Thanks again for the support. I will take the recommendations and report back. Starting with the water.

Careful using the lid, if you go to all grain. The boil drives off DMS. . You don't want the lid on.

As for boil off rate. Fill with 5 gallons and fire it up and test it. You don't have to run the burner at full hellfire after you get it to boil either. Turn it down until you have a nice rolling boil.

 

[Craigerrr]

1 pound is 1 pound. But 1 pound at 32F is not the same volume as 200F

Exactly my point. To describe it more accurately one liter of water weighs 1 kilogram. It will expand and contract with changes in temperature, but the weight will not change.

 

[Craigerrr]

With 80+ batches and typically great results, I have only used liquid yeast 2 or 3 times. Dry yeast has been very good to me!

 

[Limey]

Exactly my point. To describe it more accurately one liter of water weighs 1 kilogram. It will expand and contract with changes in temperature, but the weight will not change.

I could be picky and point out that, since you are using metric units, it is not the weight that stays stable - it is the mass!

 

[Sandy Feet]

My water sucks. North Florida is worse. Do not use tap water. Go to Publix. Buy Spring Water. You probably get the same Silver Springs sourced spring water that I get in Orlando. It makes good beer. Orlando water is awful. Jacksonville/St Augustine water is disgusting.

 

[Sandy Feet]

I make 5 gallon batches in a 16 gallon kettle for BIAB. If you go in that direction and go outside 1 gallon/1 hour for Florida as a boil off rate using a rolling boil and nothing too crazy.