Adjusting Recipe Based on Yeast Starter

[Phalangical]

Hey guys, quick question. This is the first time I've made a yeast starter. I'm planning on brewing a Belgian Tripel tomorrow evening with an OG of 1.085 so I figure this was a good brew to try a starter on. Anyway I made a 2 quart starter with about 14 oz. extra light DME. Now my recipe calls for 8 lbs of extra light DME, should I subtract the 14 oz. from the recipe since I plan on pitching the whole starter?

 

[jigidyjim]

Hey guys, quick question. This is the first time I've made a yeast starter. I'm planning on brewing a Belgian Tripel tomorrow evening with an OG of 1.085 so I figure this was a good brew to try a starter on. Anyway I made a 2 quart starter with about 14 oz. extra light DME. Now my recipe calls for 8 lbs of extra light DME, should I subtract the 14 oz. from the recipe since I plan on pitching the whole starter?

No I don't think so.

Either you pour out the starter and just pitch the yeast, in which case it doesn't matter, or you pour in the whole thing in which case you are adding liquid+dme, so it won't change your o.g. if the starter is the same as your beer, and any differences would probably be negligible. But with a 2q starter you should consider decanting before pitching.

Btw - 14oz in 2q is huge, I've never done one that heavy. But that doesn't mean it is wrong. Just curious if others do that too.

 

[Phalangical]

or you pour in the whole thing in which case you are adding liquid+dme, so it won't change your o.g.

Yeah makes sense. Also your right 14 oz is way huge, I was in a rush and did it then started doing the math, should have probably been about half that. Oh well live and learn, thanks for the input.

 

[tally350z]

The starter sounds ok.
For a normal starter at 1.040. Its 1/2 quart water to 1/2 cup DME. I believe..

 

[jigidyjim]

Yeah makes sense. Also your right 14 oz is way huge, I was in a rush and did it then started doing the math, should have probably been about half that. Oh well live and learn, thanks for the input.

Actually now that I think about it more, I'm starting to doubt the claim that I made that it doesn't affect the OG/FG. I'd have to do more math to figure it out.

I think the general advice still stands though: do your recipe as is, then add the starter, it won't affect the batch that much unless the starter is a large volume - in which case you'd want to decant anyway to avoid off flavors.

 

[Phalangical]

Its 1/2 quart water to 1/2 cup DME. I believe..

Hmm, I keep reading different numbers all over the place, not to mention everyone measures in different units.

 

[mux]

Hey guys, quick question. This is the first time I've made a yeast starter. I'm planning on brewing a Belgian Tripel tomorrow evening with an OG of 1.085 so I figure this was a good brew to try a starter on. Anyway I made a 2 quart starter with about 14 oz. extra light DME. Now my recipe calls for 8 lbs of extra light DME, should I subtract the 14 oz. from the recipe since I plan on pitching the whole starter?

Check out. Mr. Malty. Great tool.

 

[Phalangical]

Check out. Mr. Malty. Great tool.

Yeah Mr. Malty is great but it just gives you a starter size, doesn't advise on the dme to water ratio. It also doesn't have any information regarding the original question which was do I adjust the recipe based on the amount of dme used in the starter?

 

[jigidyjim]

Hmm, I keep reading different numbers all over the place, not to mention everyone measures in different units.

I do 3oz to 1q, which is slightly lighter than the standard 1 to 10 (1 g to 10 ml) - just because its an easy measurement for me to do. I don't like using volume as a measure for dme but before I switched to weight I think I did 1/2 cup dme to 1 pint water.

 

[jigidyjim]

Yeah Mr. Malty is great but it just gives you a starter size, doesn't advise on the dme to water ratio. It also doesn't have any information regarding the original question which was do I adjust the recipe based on the amount of dme used in the starter?

I guess my thinking is - whatever is left in the starter is unfermentable. So say you have 1.010 beer in the starter. If your wort ends up being 1.010 the starter makes no difference. If the wort ends up being 1.020 the starter will make your beer slightly lighter, but a 2q starter in a 5g batch only accounts for 10% of the total... so it won't make a huge difference.

Taste might be a different issue. I'd don't know what the threshold is there. I've never pitched more than 1q starters so you'll have to get someone else's input.

 

[tally350z]

Just make your normal batch the way it should be.. Make the starter the way it should be. Cold crash and decant the liquid. Add the slurry to the wort and you should be good. Even if you get a few oz of liquid in the beer thats better than adding the entire 2 quarts..

 

[tgmartin000]

Yes. Chill for a few hours, bring it back up to room temp, decant, pitch. Post aeration.

A rule of thumb : starter size in quarts X 100 = DME in grams.

So I added 50 grams to my 0.5 qt starter. This will make a starter just under 1.040.

 

[jigidyjim]

I guess my thinking is - whatever is left in the starter is unfermentable. So say you have 1.010 beer in the starter. If your wort ends up being 1.010 the starter makes no difference. If the wort ends up being 1.020 the starter will make your beer slightly lighter, but a 2q starter in a 5g batch only accounts for 10% of the total... so it won't make a huge difference.

To finish out my exercise:

If you remove 14 oz DME but leave your batch as 5gallons, you decrease your OG by 10%. Pretend it is 100% fermentable so your FG decreases 10% too. In order to get back your 10% loss with a .5 gallon starter (10% of total volume), your starter's OG/FG would need to be ~100% larger than your wort's.

If you remove 14 oz of DME but also make your main wort .5g smaller to make room for the starter, then I think you end up with the same OG/FG as what the recipe wants, but again, the taste is different and hop utilization will be different - you'll have a different beer.

This is very rough, but I think it's in the right direction.

 

[Phalangical]

Thanks for all the responses guys, jigidyjim seems to be most on my level. My understanding is there are two schools of thought when it comes to pitching a starter. One is to cold crash the starter after it has fermented out completely, decant, and pitch the yeast, not my intention due to time constraints. The second being to pitch the entire starter when the starter reaches high krausen. I'm gonna go ahead and pitch the entire thing without adjusting the recipe based on jigidyjim's analysis which I tend to agree with. Really wasn't concerned about it, just wanted to get a better understanding.