Testing gravity with new refractometer

[Mike Newman]

6 days ago I made an extract IPA (recipe in attachments). I fermented at 63 inside a temperature controlled fridge. Today I still have pretty steady bubbles coming from airlock (1 every 5-6 seconds). What I am wondering is how to test the wort with my newly purchased refractometer and when to dry hop? I only have the 5 inch plastic droplet thing that came with the refractometer which is not long enough to get a sample, however I want to check the gravity to see where I am at in the fermentation. I am planning to dry hop with .25 oz each of cascade and Citra, but I have read you are not supposed to dry hop in the secondary until the beer has steadily been at FG for 2-3 days. Can anyone provide some advice so I don’t ruin my beer or oxidize it trying to get a sample??

 

[kh54s10]

First of all you need to make a correction for the presence of alcohol. There are online calculators that will get you close. Some say that all of them are slightly off. A hydrometer will give a better reading.

But you only need a couple drops. You could probably sanitize something solid get it wet then let it drip onto the refractometer.

 

[Mike Newman]

First of all you need to make a correction for the presence of alcohol. There are online calculators that will get you close. Some say that all of them are slightly off. A hydrometer will give a better reading.

But you only need a couple drops. You could probably sanitize something solid get it wet then let it drip onto the refractometer.

I have a hydrometer but it requires 80-90 ml to get a solid reading which makes me uneasy when it comes to sanitation if I was going to put it back in with the rest of beer in fermenter. I will try your suggestion of sanitizing something long enough to obtain a couple drops for a sample.

 

[S-Met]

Drink your sample. Yes, warm and still developing, but can clue you on what the end product may be like.

 

[Boomer]

Just bought my first refractometer but I think I’m always going to run it side by side with a hydrometer just to compare. Plus, I refuse to make a beer without drinking hydrometer samples at various points throughout the process. It’s honestly one of my favorite parts of brewing because it indicates exactly what each prior step has done to the flavor of the beer.

 

[Mike Newman]

Just bought my first refractometer but I think I’m always going to run it side by side with a hydrometer just to compare. Plus, I refuse to make a beer without drinking hydrometer samples at various points throughout the process. It’s honestly one of my favorite parts of brewing because it indicates exactly what each prior step has done to the flavor of the beer.

So I tested with refractometer this morning and it read 1.032 after 6 days. Does this mean I underpitched? I read that sometimes Bry-97 has a really long lag time so I’m thinking maybe that’s the cause. I added the extra corn sugar in hopes of drying out this batch, however it’s still under attenuating...

 

[Boomer]

Checked it with a hydrometer? Like I said, even when I’m using this new refractometer, I intend to cross-check against what I know.

Also, one thing I always do, and I don’t mean to sound condescending so please don’t take it that way if that’s how it comes across, is I try to reserve knee-jerk reactions until I’ve checked it twice, with a 24 hour interval between checks, and get the same number. I’d hate to mess with it if it’s just creeping towards my planned FG. I’ve found that a slower fermentation period often yields less off flavors than trying random things to get it to go.

 

[Mike Newman]

Checked it with a hydrometer? Like I said, even when I’m using this new refractometer, I intend to cross-check against what I know.

Also, one thing I always do, and I don’t mean to sound condescending so please don’t take it that way if that’s how it comes across, is I try to reserve knee-jerk reactions until I’ve checked it twice, with a 24 hour interval between checks, and get the same number. I’d hate to mess with it if it’s just creeping towards my planned FG. I’ve found that a slower fermentation period often yields less off flavors than trying random things to get it to go.

Solid advice friend, no offense taken at all! I’m gonna warm take it out of the fermentation chamber and take it up to 68 (house temp) for a DR and see if the warmth will finish things up.

 

[Mike Newman]

Checked it with a hydrometer? Like I said, even when I’m using this new refractometer, I intend to cross-check against what I know.

Also, one thing I always do, and I don’t mean to sound condescending so please don’t take it that way if that’s how it comes across, is I try to reserve knee-jerk reactions until I’ve checked it twice, with a 24 hour interval between checks, and get the same number. I’d hate to mess with it if it’s just creeping towards my planned FG. I’ve found that a slower fermentation period often yields less off flavors than trying random things to get it to go.

Also I added the corn sugar in the boil NOT in the primary for better attenuation...

I think that’s what you were referring to with the “knee jerk reactions”. So just to clarify I have not added anything to facilitate fermentation at this point.

 

[S-Met]

I don't own a refractometer, but I understand that its readings are skewed by alcohl. Did you adjust your read to compensate?

 

[Yooper]

For a refractometer, there are a couple of things you need to do. First, calibrate it with your hydrometer. That has to be done to get your 'wort correction factor'. If you don't yet know your wort correction factor, you can use the default- BUT it won't be as accurate as it could be.

Then, use some software to correct the reading, since alcohol impacts the refraction of light and skews the reading.

http://seanterrill.com/2012/01/06/refractometer-calculator/

 

[dmtaylor]

The following topic on the AHA forum dives DEEP into individual experiences with a refractometer calculator that was designed specifically to give the ability to use the refractometer accurately DURING fermentation, versus not just at the very end which is what other calculators do.

https://www.homebrewersassociation.org/forum/index.php?topic=28544.0

 

[Mike Newman]

So... I have been doing research all day and have come to the conclusion that I made an extremely fermentable wort and thats why the FG just keeps on dropping! )I took a hydrometer reading prior to pitching yeast and it was 1.066 or around 16 Brix. Today my refractometer read around 8.5Brix at 9am and now it’s at 7Brix (these could also be sample errors as there is still active Krausen occurring on top). My intention was to have a 6% IPA but it’s now looking more and more like it’s gonna be above 7%. Would it be a bad idea to cold crash the beer to decrease the ABV or should I let it finish out to avoid any off flavors?

 

[deadwolfbones]

At 7 Brix you'd already be at 7.7%, according to the Brewer's Friend calculator (and assuming a 1.0 wort correction factor.

 

[Mike Newman]

At 7 Brix you'd already be at 7.7%, according to the Brewer's Friend calculator (and assuming a 1.0 wort correction factor.

I used that same calculator earlier with the same results... which bums me out (was hoping for an easy drinking IPA). I am anxious for this beer to stop fermenting so I can compare the true hydrometer FG and the Brix calculated ABV.

 

[S-Met]

Something may be off. What ueast did you use?

And did you add anything else? At OG 1.066, you should max out at 6.65abv.
3lb dme, 4.6oz dextrose and a 35% from steeping grains should be close to 1.066. Need another sugar sourceto exceed 7%

 

[S-Met]

Did you build or buy the kit. How did you measure the dextrose, weight or volume?

 

[Mike Newman]

Did you build or buy the kit. How did you measure the dextrose, weight or volume?

I based the recipe off a one gallon batch I made a while ago. I made the recipe in beer smith and took a hydrometer reading which was around 1.066-1.068. The yeast is Lallemand Bry-97 West coast ale. Nothing in the fermenter looks out of order (I.e. no suspicious bacteria formation) and there is a decent Krausen on top still. I am just going to let it go until Friday and take a hydrometer reading for the FG.

 

[Mike Newman]

Did you build or buy the kit. How did you measure the dextrose, weight or volume?

All measurements were taken on a digital food scale

 

[dmtaylor]

So... I have been doing research all day and have come to the conclusion that I made an extremely fermentable wort and thats why the FG just keeps on dropping! )I took a hydrometer reading prior to pitching yeast and it was 1.066 or around 16 Brix. Today my refractometer read around 8.5Brix at 9am and now it’s at 7Brix (these could also be sample errors as there is still active Krausen occurring on top). My intention was to have a 6% IPA but it’s now looking more and more like it’s gonna be above 7%. Would it be a bad idea to cold crash the beer to decrease the ABV or should I let it finish out to avoid any off flavors?

Possible infection if it's still going. Definitely do NOT cold crash it yet. See what it does first.

 

[S-Met]

Opinion: infection not likely. Cool temp slows fermenting. Let it ride as others say.

I'm not familiar enough with that yeast to know its efficiecy. I could look into it later, but since it appears that it is still fermenting... lets see a stable fg before thinking about the what if's.

 

[Mike Newman]

Opinion: infection not likely. Cool temp slows fermenting. Let it ride as others say.

I'm not familiar enough with that yeast to know its efficiecy. I could look into it later, but since it appears that it is still fermenting... lets see a stable fg before thinking about the what if's.

Decided to roll the dice today as the airlock slowed down significantly after warming it up for 24 hours at 70. Just racked to secondary with dry hop and got an FG of 1.012 which is what I was shooting for!

 

[S-Met]

Whats the acronym all over the forum:
RDWHAHB

All will work out.