Starter gravity question

[rebel_scum]

So I just made a starter for my dunkel, and just for kicks I started taking gravity readings periodically through the 15 min boil.

I used 1cup of DME and 4 cups of water to start, which I have read is pretty accurate to achieve ~1.040, but when I took a refractometer reading after adding to the boil it was at a 1.078?

I calibrated the refract with distilled water, continued taking readings (which obviously were going the wrong way) and finally decided to add water until I got to 1.038 which is my target. Wound up putting about 2 more cups of water into the boil.

Final OG reading at 65deg before pitching was 1.039.

Why did I need to add so much water to the formula? Considering this is for a dunkel and I don't want to over pitch will the starter going from 1L to about 1.5L have any effect on the banana / clove ratio?
I have been using starters for my last 3 brews and didn't take readings on them. I just assumed that the 1/2 c to 2 c formula would be pretty accurate.

Thanks!

Jeff


Sent from my iPad using Home Brew

 

[Beernik]

Don't worry about the volume of liquid so much. You want to chill and decant liquid off the yeast before pitching anyway.

The best way to do starters is to use a calculator like brewers friend or mr malty. That way you are calculating the yeast population you are adding.

 

[rebel_scum]

I used the brewers friend calculator, the problem is it assumes a 1.038 gravity for the starter.

I was just wondering why a commonly accepted ratio of DME to water would be so far off that mark. If I hadn't taken a reading I would have been pitching one wyeast pack into a 1.078 starter wort and that doesn't seem like a good idea.

I will try the chill and decant to remove some excess. Thanks for the fast reply!



Sent from my iPhone using Home Brew

 

[Beernik]

John Palmer has in his online book 1/2 cup DME to 1 pint water for a 1.040 starter.

You might be thinking 1 cup DME to 1 quart water and used a pint instead.

(EDIT: I just figured out that 1 quart = 4 cups, which is what you did. Sorry, I never learned imperial volume unit conversions.)

Still the best way to avoid confusion is to measure DME in weight instead of volume.

And you can change the OG of the starter when using brewers friend. I had to before I got a 2L flask.

 

[flars]

One cup of DME, according to NBs calculator, weighs 5.8 ounces. Four cups of water equals 0.946 liters. This yields an OG of 1.061 using Brewers Friend yeast starter calculator.

Six cups of water and one cup of DME equates to an OG between 1.040 to 1.041.

When it comes to DME for starters and priming sugar for carbonation volume measurements are not as accurate as weight.

 

[rebel_scum]

Excellent. I didn't back out the conversions using weight to get the OG, I just used the 1/2 cup to 2 cups ratio I have seen on numerous posts and videos and thought that would get me to 1.04, which I left in the OG box on the calculator.

Just for future reference, when using the calculator- if I want to do a 1L starter for instance- it tells me to use 4.0 ounces DME to achieve a 1.040 gravity. Would that mean I would use 1L of water and 4.0 oz of DME altogether prior to boiling? Or do I need to figure out how much water to use by starting with the 4.0 oz DME using another calculator?

Sorry- I'm just a bit confused about the "1L" thing... I always thought that one liter was the size of the starter you wanted after boiling/pitching was done- looks like that was incorrect. Think I have most of the rest of my brewing processes nailed down, just want to get the yeast thing perfected to take it to the next level!

Thanks for all the help!

Jeff




Sent from my iPad using Home Brew

 

[Beernik]

I take it to mean 4oz of DME and enough water to make the starter "wort" 1L in volume. Then you pitch the yeast in it.

 

[flars]

Excellent. I didn't back out the conversions using weight to get the OG, I just used the 1/2 cup to 2 cups ratio I have seen on numerous posts and videos and thought that would get me to 1.04, which I left in the OG box on the calculator.

Just for future reference, when using the calculator- if I want to do a 1L starter for instance- it tells me to use 4.0 ounces DME to achieve a 1.040 gravity. Would that mean I would use 1L of water and 4.0 oz of DME altogether prior to boiling? Or do I need to figure out how much water to use by starting with the 4.0 oz DME using another calculator?

Sorry- I'm just a bit confused about the "1L" thing... I always thought that one liter was the size of the starter you wanted after boiling/pitching was done- looks like that was incorrect. Think I have most of the rest of my brewing processes nailed down, just want to get the yeast thing perfected to take it to the next level!

Thanks for all the help!

Jeff




Sent from my iPad using Home Brew

A one liter starter is one liter of water, post boil, that the DME is added to. After pitching the yeast the volume will be greater, but the ratio of DME to water remains the same to retain the correct SG.

 

[Beernik]

I don't think it matters that much.

Let's say the calculator really means 1L of water + 4oz of DME = a 1.040 1.2L starter.

And what I have been doing is 0.8L of water + 4oz of DME = a 1.050 1L starter.

My yeast might be a little more stressed due to the higher OG, but they both grow the same population.

Of course, now that I replaced my 1L with a 2L flask, I don't have to worry about the volume available for my starter as much.