split batch specific gravity issue

[Jkrags]

Hi guys... so we're still kind of newbies but we're trying some new things. I went to my local brew shop and bought a Irish stout kit, I told him we wanted to split it into 2- 2 1/2 half gallon batches and make a Holiday style stout out of the second batch. He gave me an extra pound of DME and we also got a pouch of omega ale yeast. AT 55 minutes we split the batch, finished the regular batch with half of the bittering hops , terminated the boil and put that into the ice bath, pitched with the dry yeast from the kit. That batch had an OG of 1.05

In the mean time we bought the second batch back to a boil added the extra DME and some spices in a bag. We probably boiled that for about another 30 minutes. Cooled it and that had an OG of 1.06. Pitched with the Omega and send both batches off to do their thing.

We went today to move them to the secondary. First batch had a SG of 1.012 and Tasted good. Now here's the weird thing ...The second batch is reading 1.020! Am I right in that this means it has less alcohol? which makes no sense! Or do you think that the second batch is still fermenting and we need to wait on it? And I'm not sure but also the package of yeast also seem to me to not puff out as much as we are used to.

Any input appreciated!!

 

[grampamark]

You added more fermentables to the second half with the DME and also boiled it longer, concentrating the sugars. You also had a higher OG with that half and used a different yeast. Give it some more time; it probably hasn't completely attenuated.

Mark

 

[Pkrd]

You added DME so should expect a higher OG and FG. Were the final volumes the same on both batches(did you compensate for the extra 30 min boil off)?

First batch went from 1.05 to 1.012 = 5%
Second batch went from 1.06 to 1.02 = 5.25%

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

 

[Jkrags]

Thanks guys.

Mark - My instinct is that you are right we should probably let the second batch stay in the primary.

Pkrd - when we said we wanted a higher gravity I thought it would be like a 7! My guess now is that 1 extra# of DME would not be enough to do that? What do we know. Ug. And yes you are right we did have to compensate, added about 32 oz to second batch.

 

[Calder]

I'm not sure your Original Gravities are correct. Or I need more information from you to agree with your numbers.

First question - Why are you transferring to secondary? If you don't know why, then there is no reason to do so. Most people now do not rack to secondaries (I'm one of the few who still do - for my own reasons, but I am an exception). This time of year is especially problematic for people transferring to secondary. If the beer gets too cold for the yeast to ferment, it will drop before finishing, and if you rack it, you leave behind the yeast you need to finish it.

I assume you partial boil and make up the volume in the fermenter. You took half the wort out for the first batch, and left half and added 1 lb of DME. If you split was accurate, the DME would add 18 points to the gravity reading in 2.5 gallons; it is basically sugar, and will do this. This is why I don't believe your OG readings. When you add make-up water to fermenters, it doesn't always mix well, and you can get incorrect OG readings. The yeast will find the sugar, so no worries.

List your ingredients for the initial boil, volume you boiled, how much you removed, and what you did for the second half, and someone will be able to calculate what your gravities should be.

Yes, 1.020 is probably not done.

Don't worry the yeast pack did not swell. The yeast is working, so you should be OK.

I'm a little concerned about your statement "finished the regular batch with half of the bittering hops". Maybe you did not say it correctly. Bittering hops should be added at the start of the boil, not the end. Did you mean 'finishing' hops, or did you mess up?

 

[Jkrags]

Hi Calder - thanks for your response!

Yes Started with 2 1/2 gallon partial boil, and yes misspoke, meant the finishing hops!

Fermentables

3.3 # Dark LME
2.0 # Dark DME
.5 Maltodextrin

Grains
12oz Caramel 60L
4oz Roasted Barley
4oz Black Patent

Hops
1oz Magnum
.5oz El Dorado

Yeast
1 dry Sachet

Extras
1# Dark DME
Omega Ale Yeast
Bag of spices - cinnamon, nutmeg, Vanilla


At 55 min took out 1 & 1/4 gallons to a separate pot. Terminated boil on batch one added about a gallon of water and took the reading with hydrometer got apprx 1.05.

Bought 2nd batch to a boil, in hindsight should have added more water then to the pot right?? Added the 1# dark DME let go for about 30min. Added the rest of the finishing hops, the spices, terminated the boil, cooled, added water, needed more than anticipated (PKrd was right about that!) almost 2 gallons. I believe we got a 1.06, but always have a hard time reading the hydrometer in foamy wort :-(. Thinking about getting a refratometer.

THANK YOU!

 

[Calder]

Total points in initial boil would be ~260, so half would be 130. In your initial pull, if you made it up to 2.5 gallons the gravity would be 130/2.5, or 1.052. which is close to what you got.

For t he second batch, assume you had 130 of the original points and added 45 points with the DME = 175 points. In 2.5 gallons that would be 175/2.5, or 1.070.

Most of the sugar content is standard - all of it is just different forms of sugar that have to meet certain sugar levels. The only real variable in the sugar is the grains. I estimated 15 points for the grains.

Why the Maltodextrin? I used some when I started (a long long time ago), I thought it would add malt flavor, and body. I guess it does, but it is unfermentable and therefore just raises the FG and makes the beer sweet. Since extract is not fully fermentable, there is no reason to use it unless you are trying to get a beer to end sweet for some reason. Don't use it in future unless you know why you want to use it. You can get the same malt flavor by using extract, but end up with a drier beer.

 

[Jkrags]

Hi- Thanks again for your input on this!

Course like a typical new Brewer I did not know there was a method for attaining points for The sugar to calculate what the potential og would or should be. Very interesting!

We have only been brewing with kits so we used whatever was in there as per the instructions. We definitely did not want a sweet beer so I will take your advisement about maltodextrin in the future!

 

[Remos112]

I did not know there was a method for attaining points for The sugar to calculate what the potential og would or should be. Very interesting!

This one is for extract:
https://www.brewersfriend.com/extract-ogfg/
and if you want to calculate even more there is this one:
https://www.brewersfriend.com/homebrew/recipe/calculator/

When I was still doing extract I never got reliable OG hydrometer samples because it is difficult to mix the extract and water to one mass, this is where calculators come in handy, and very usefull for recipe building as well!