Yeast Starters and OG

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jmmy3

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Ok so I had a little complication with my brewday yesterday and I haven't been able to find a clear answer. I'm hoping someone here can help me, as I assume it has to be very common.

I made a 2 liter yeast starter a couple days before brewing my NB Dead Ringer kit. Since this was a bigger yeast starter than I am accustomed to doing I assumed it would be best to bring the wort volume to around 4.5 gallons after cooldown, since the 2 liter starter should have brought it to my 5 gallon mark. Without thinking, I took my gravity reading before pitching the yeast, even though there was no way it could have reached my target gravity, being at only 4.5 gallons. Dead Ringer's target OG is 1.067 and I came up with 1.076. I'm unsure why most directions tell you to take the reading before pitching yeast, but I'm just assuming it is to avoid infections? Anyway, I'm wondering how I can counteract this in the future. Do I just get a reading right after pitching? Or do I bring the wort to 5 gallons before pitching the starter, regardless of it's size?

Also, is it necessary to factor in the DME I used in the starter to get a more accurate ABV estimation for the final product? I've done a starter with all three of my batches so far, but it's still sort of unknown territory to me. I've done a little research but haven't found a good resource for starter info. Any help in this matter would be appreciated!
 
You should have topped off to 5 anyways.. Cold crashed the starter, decanted it, and then pitched.. It will be fine, still beer..
 
Yeah I know the brew will be ok but I like to be precise with my gravity and whatnot. It's nice to know the ABV and such. There's no way to get a better reading without decanting the starter? I mean is it really that dangerous to take a reading after pitching?
 
Just calculate the abv off of the wort... ignore the starter for your measurements

I'm unsure what you mean. I have the OG from before pitching, but how do I get the FG without factoring in the starter? Is there a method to disregard that 2 liter addition?
 
Yeah I know the brew will be ok but I like to be precise with my gravity and whatnot. It's nice to know the ABV and such. There's no way to get a better reading without decanting the starter? I mean is it really that dangerous to take a reading after pitching?

Top off your fermenter to your final volume, then take a reading. Your starter should ideally be cold crashed and decanted, so that you will be adding just yeast slurry, and not much starter 'beer', and therefore not making any change in your gravity reading that you can even measure with a normal hydrometer. If you take a gravity reading after you pitch the yeast, you are losing yeast cells and potentially impacting the final quality of your beer.
 
I'm unsure what you mean. I have the OG from before pitching, but how do I get the FG without factoring in the starter? Is there a method to disregard that 2 liter addition?

Just measure the OG when its done fermenting and ignore everything else...

the abv at the point it will be close enought, it's not like you have a life or death calculation on your hands here
 
Gotcha, guess ill have to make a habit to cold crash my starters. Thanks for the help.
 
Gotcha, guess ill have to make a habit to cold crash my starters. Thanks for the help.

Yeah good idea. Just to get an idea for you most recent batch though, lets do a little math so you can figure out your gravity for this batch.

4.5 gallons * 76 = 342
.5 gallons * 30 = 15
= 357 points
357/5 gallons = 71.4

So your OG was probably pretty close to 1.0714. I'm assuming your starter gravity was around 1.030. Not too far from your target of 1.067 :mug:

EDIT: changed values to reflect your starter OG rather than FG
 
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