Yeast starter help - newbie

[churchofthebrownbottle]

Hi everyone,

I am trying to take my brewing to the next level and am starting to do yeast starters. I told to make high gravity beers, so I needed to use a 2 step yeast starter. I was making an imperial weizenbock with OG of 1.098. I calculated with a pitch rate of 1.5 per what I read on the Wyeast website (Wyeast 3638). When I pitched the yeast I had 2 solid days of vigorous fermentation. After 4 weeks, when I took the final gravity, it was only 1.045 (goal was 1.016). What could I have done wrong?

I currently have a scotch ale in the fermenter (pitched the yeast 2 days ago). I used a much lower pitch rate of 1.0 this time. Again I needed a 2 step starter. I am using Gigayeast GY044 Scotch Ale yeast. After pitching the yeast, I had a very vigorous fermentation (temp went up 10 degrees from 68-78 even with using a ssbrewtech brew bucket with chiller in about 24 hrs). Now not much is happening. Was the primary fermentation too fast?

Thanks everyone for your time!

 

[catalanotte]

Are you using a hydrometer or refractometer for your gravities?

 

[churchofthebrownbottle]

I am using a refractometer

 

[catalanotte]

I am using a refractometer

Can’t use a refractomer for final gravities without a correction. Once the alcohol content builds it affects the refraction through the sample. Try this calculator, with a 1.03 for a correction factor. Refractometers are calibrated for sucrose and need a small correction factor for average wort sugars. 1.02-1.04 is the typical range people see if they test this. I ran your numbers through the calc and it looks like your at 1.015, pretty much on the money.
https://www.brewersfriend.com/refractometer-calculator/