SAF 05

[argodzilla]

Second all grain batch had an OG of 1.054. Bbwesmith called for 1.1 packages of SAF 05.
I pitched a single packet last Friday. Friday night I had slow bubbling taking place. The blow off hit it's peak on Sunday. Activity slowed quickly after Tuesday and by Wednesday I wasn't seeing much airlock activity. I just took a refractometer reading and the reading has me concerned. 1.023. I was expecting 1.010 or so. Should I be looking to pitch a bit more SAF 05? Fermentation temp has been steadily held to 68. Thanks
Matt

 

[beermanpete]

Did you apply the correction factor for the reading obtained from the refractometer?

https://www.brewersfriend.com/refractometer-calculator/

 

[deadwolfbones]

Yeah, you can't use uncorrected refractometer readings once there's alcohol in solution. You need to use a calculator to adjust it.

 

[argodzilla]

The right side of my scale says SG Wort.

It has the scale built in.

 

[deadwolfbones]

The right side of my scale says SG Wort.

It has the scale built in.

Use the calculator. You'll get the right(ish) reading.

Edit: Just checked and it looks like you're sitting on 1.008.

 

[RM-MN]

The right side of my scale says SG Wort.

It has the scale built in.

But you no longer have wort, you have beer. Use the correction table or use a hydrometer (more accurate).

 

[beermanpete]

The right side of my scale says SG Wort.

It has the scale built in.

Exactly the point. Wort is not beer. The refractometer measures sugar content by detecting the angle of light refraction through the sugar. The alcohol in finished beers interferes with the measurement. The correction factor compensates for the error caused by the alcohol.

 

[argodzilla]

Using the calculation it comes to 3.57%. Same as what I was getting using the SG Wort numbers in a traditional abv calculator... Maybe I missed something... won't be the last time.

 

[argodzilla]

Haha....I'm going to go watch a YouTube video. I don't think I'm smart enough to use that calculator.

 

[Yooper]

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

Use the first reading, and the last reading, and ignore the bottom box (1.040 is good enough), and then click calculate. That will give you a decent estimate.

 

[argodzilla]

Ok...5.8% . Thanks for sending me in the right direction. According to the calc...I have a current gravity of 1.007.

 

[Yooper]

Ok...5.8% . Thanks for sending me in the right direction. According to the calc...I have a current gravity of 1.007.

It's not 100% accurate, without knowing your actual wort correction factor, so it's an estimate, but if you don't want to break out your hydrometer, it's good enough to know it's somewhere between 1.006 and 1.010, likely.