Bumping up Second Runnings for Starters?

[TRainH2o]

Beer Math time.

Is there a calculator that you can plug in the amount of your leftover runnings, the specific gravity and then know how much DME to add to get a 1.040 starter wort?

I'm sure there is, I just can't find it.

I have 1/2 Gallon 1.012 wort. I want to make a 1/2 Gallon 1.040 starter wort. So how much DME should I add? Or at what point is it not worth it? Thanks.

 

[momobono]

http://brewzor.com/gravity-correction-calculator/

Boom. Happy starter wort brewing.

edit: Alright, i saw this was just an android app. Here's the beery math behind it:

Gravity points (GU) = (last two numbers of gravity reading) * (gallons of wort you have)

For DME, the equation is (GU_target - GU_mash)/36 = lbs of DME

For your application:
(12)(0.5) = 6 GU for your current starter
(40)(0.5) = 20 GU for your target starter
(20 - 6)/36 = 0.389 lbs DME

So 0.4lbs will do you just fine.

As I said before: Boom.

 

[TRainH2o]

Very cool, thanks. I'm running Android on my Nook Color, I wonder if I can install it?

 

[ajf]

http://brewzor.com/gravity-correction-calculator/

Boom. Happy starter wort brewing.

edit: Alright, i saw this was just an android app. Here's the beery math behind it:

Gravity points (GU) = (last two numbers of gravity reading) * (gallons of wort you have)

For DME, the equation is (GU_target - GU_mash)/36 = lbs of DME

For your application:
(12)(0.5) = 6 GU for your current starter
(40)(0.5) = 20 GU for your target starter
(20 - 6)/36 = 0.389 lbs DME

So 0.4lbs will do you just fine.

As I said before: Boom.

I wouldn't trust that calculator, and it wouldn't work for stepping up a starter.
The site says the extract PG for LME is 44, and the extract PG for DME is 36.
They've got them the wrong way round. DME adds about 44 points per gallon, LME adds about 36 points per gallon (because of the extra water in it).
If you start with 1/2g starter at 1.012, you can't add any extract to end up with 1/2g at 1.040. If you start with 1/2g and add anything, you will end up with more than 1/2g.
What you need to do is to chill the original starter to cause the yeast to flocculate, and then drain off the clear wort and discard it.
Then you need to make a new 1/2g starter using about 7 oz DME, and add the slurry left after decanting the clear wort from the original starter.

-a.

 

[TRainH2o]

I'm starting with 1/2 Gallon of wort from my second runnings, I have not made a starter yet. I was wanting to bump up the SG so it would be 1.040. I realize the total volume will change slightly.

So basically, I'm adding DME to my 1/2 Gallon of 1.012 wort to make it 1.040, and as close to 1/2 Gallon as I can.

Per a friend's suggestion, I added 5.5 ounces of DME to my 1/2 of wort and did a light boil. My actual volume was slightly over 1/2 Gallon but I also boiled off a bit. I didn't measure the gravity of the starter but the yeast are happy with it.

 

[momobono]

If you start with 1/2g starter at 1.012, you can't add any extract to end up with 1/2g at 1.040. If you start with 1/2g and add anything, you will end up with more than 1/2g.

What you need to do is to chill the original starter to cause the yeast to flocculate, and then drain off the clear wort and discard it.

It was my understanding that you only have wort, not leftover starter? If so, allowing yeast to settle in the cold (not flocculate, that's a natural biological process that happens at fermentation temperature) wouldn't have any effect.

With regards to initial volume vs. final volume, boiling the starter for the 10 minutes recommended by Palmer would effectively cancel out any volume change incurred by adding the small amount of sugar. At that size, and at starter boil times, volume gain/loss isn't an issue.

And gravity points are gravity points, no matter how large the volume of wort is, so the equations are definitely scalable. It's not an estimation like hop utilization eqn's are, it's a direct relation between volume and sugar by weight %.

It may have been an error on my part, but I'd like to see some citation before telling me I'm wrong about the 36 points / #DME.

 

[momobono]

Glad to see the yeast are happy!

These threads can quickly become a classic case of " thinking too much can ruin your beer." what are you brewing with this starter, and what yeast are you using?

 

[TRainH2o]

Glad to see the yeast are happy!

These threads can quickly become a classic case of " thinking too much can ruin your beer." what are you brewing with this starter, and what yeast are you using?

I'm doing my first India Brown Ale, similar to DogFish Head. I'm using Wyeast Ringwood Ale because I hear that's what DFH uses. It's attenuation is rather low but it states is has unique fermentation and "flavor characteristics. Distinct fruit ester and high flocculation provide a malty complex profile, also clears well. Thorough diacetyl rest is recommended after fermentation is complete."

It should be interesting.

 

[ajf]

It was my understanding that you only have wort, not leftover starter? If so, allowing yeast to settle in the cold (not flocculate, that's a natural biological process that happens at fermentation temperature) wouldn't have any effect.

With regards to initial volume vs. final volume, boiling the starter for the 10 minutes recommended by Palmer would effectively cancel out any volume change incurred by adding the small amount of sugar. At that size, and at starter boil times, volume gain/loss isn't an issue.

And gravity points are gravity points, no matter how large the volume of wort is, so the equations are definitely scalable. It's not an estimation like hop utilization eqn's are, it's a direct relation between volume and sugar by weight %.

It may have been an error on my part, but I'd like to see some citation before telling me I'm wrong about the 36 points / #DME.

Yes, I misunderstood the OP. My fault, not his.
I assumed that his starting point of 1.012 was because the wort had fermented (hence the assumption that he was stepping up a starter).
One mistake leads to another. If the starting wort contained yeast, you couldn't boil some DME in it without destroying the yeast. As the starting wort doesn't contain yeast, I agree that the small amount of DME would not make a significant difference to the final volume.

Sorry for giving incorrect information.

As for the extract potential of DME, see http://***********/stories/article/...618-extract-for-all-grainers-advanced-brewing
or http://www.howtobrew.com/section1/chapter3-4.html (Palmer's estimate for the pppg of DME is a bit lower than most estimates. Beersmith uses 44 pppg, Promash uses 46 pppg.

-a.