Stop fermenting, help!

[Brandon8200]

So I did my first all grain big beer. 5 gal strong scotch ale. OG was 1.072. Today is 5 days in the primary fermenter (stainless conical) and it stopped at 1.03. I did a 1 liter starter plus 2 additional pks of wyeast. Fermentation temp was steady at 68F, pure oxygen added for 1 min....brew day was flawless. I'm really confused why it stopped. Taste is super sweet right now so....should I do a starter and pitch at high krausen?

 

[oceanic_brew]

Can you warm it up a little bit and give it a good swirl around (without opening) ?

 

[Yooper]

Have you checked your hydrometer in plain water to make sure it's reading correctly? If your using a refractometer, toss it aside and get a hydrometer reading.
It'd be really unusual for it to stop at 1.030. How did the mash go?

 

[eRicphtgr]

So I did my first all grain big beer. 5 gal strong scotch ale. OG was 1.072. Today is 5 days in the primary fermenter (stainless conical) and it stopped at 1.03. I did a 1 liter starter plus 2 additional pks of wyeast. Fermentation temp was steady at 68F, pure oxygen added for 1 min....brew day was flawless. I'm really confused why it stopped. Taste is super sweet right now so....should I do a starter and pitch at high krausen?

not sure what yeast you use, but an ale you can normally go up to 74F to ensure a complete ferment

 

[ba-brewer]

which yeast did you use, why do a starter then add extra pouches of yeast?
Is it 5 days of fermentation or 5 days since the pitch? You have attenuated 58% in 4 or 5 days of fermentation give it a couple more days.

The bulk of the fermentation is done, bumping the temp will help keep the yeast working without adverse affects.

 

[Brandon8200]

I used Wyeast 1728 Scottish Ale. I used a starter plus 2 pks because according to beer smith I needed a little over 300 billion cells for my pitch. A starter plus 2 pks would give me 400 billion. I didn't want to under pitch. I swirled it and I can try to bump the temp by moving it out of my basement to upstairs where the temp is slightly warmer

 

[ba-brewer]

I have not used the yeast calculator in beersmith even though I use the program for recipe design. I use mrmalty.com or the calculator at brewunited.com if I need to do a multi step starter. Just seems funny to do a starter and add extra packets but that would work, normally I would either use more packets or build a bigger starter.

The specs for 1728 say it has an attenuation of 69 to 73 so when you measure the gravity at 1030 you were 75 to 85 percent to the published specs. That seems reasonable for 4 or 5 days. Some yeast slow down in finishing up that last part of the attenuation, give it a few more days. It also says that yeast has high flocculation and some british yeasts drop like a rock a little early, moving it around and getting it warmer should help.

 

[Brandon8200]

Thanks for the info. I only have the equipment to do a 1L starter. My thought was to use the additional packs to reach the desired yeast cell count. Lesson learned...I will buy a larger flask to create the right size starter.

 

[ba-brewer]

Certainly easier to build a single large starter, but doing a smaller starter and using a portion of that first starter to make a second starter and combine the two can work too. Only being able to do a 1lire starter does seem a bit restricting. Some times the yeast is not too viable so you need to do multi steps anyways, having the equipment to do different size starters is useful.

I choked when I seen the price of the large flasks so I tried using a 1 gal jug and found it worked OK with my DIY stir plate. Takes some fine tuning on spin rate and position because of the rounded bottom but it works fine when set right. I use quart and half gallon mason jars for my smaller starters.

Forgot to mention that it seems like I get slightly less or closer to the bottom range of attenuation for some yeasts on the first pitch, repitches of the yeast generally come out closer to the upper end of the range or a bit higher.

I think your current beer will be fine and good luck on your future ones.