Fermenation observation

I brewed 2 beers a week ago today- a dry stout and a hefe. I pitched a dry yeast (S-04) into the stout and a liquid yeast into the hefe. No starter for either one. The stout started up within a few hours. The hefe within 8 hours, but at a slower pace. The krausen fell in the stout in about 3 days. The hefe was bubbling into the airlock at day 3 and is slowed down now. I found this to be an interesting contrast. The OG’s of the 2 beers are very similar. Fermenting at the same temp too. This is only the second dry yeast batch I’ve done in over 15 yrs of brewing. Does this contrasting fermentation sound normal? I expected a big krausen from the hefe, of course. But I didn’t expect the stout to slow so quickly. I haven’t checked a gravity. I’m going to wait another week. Any thoughts?

This sounds about right. Dry yeast have a lot more yeast cells, and is therefore “ready to pitch”. Most liquid yeast don’t have quite enough cells for a healthy 5 gallon fermentation. It will ferment without a starter, but will have a longer lag time, and the yeast cells will be slightly stressed, which may produce off flavors and increase mutation rate for future generations.

Even with a healthy starter, there are so many different types of liquid yeast with different fermentation profiles (temp, duration, vigor, etc) that you really can’t expect identical fermentation from two types of yeast. I’ve even had instances where I pitch the same type of yeast and one takes off faster than the other; probably due to package age or handling or something.

[quote=“CliffordBrewing”]This sounds about right. Dry yeast have a lot more yeast cells, and is therefore “ready to pitch”. Most liquid yeast don’t have quite enough cells for a healthy 5 gallon fermentation. It will ferment without a starter, but will have a longer lag time, and the yeast cells will be slightly stressed, which may produce off flavors and increase mutation rate for future generations.

Even with a healthy starter, there are so many different types of liquid yeast with different fermentation profiles (temp, duration, vigor, etc) that you really can’t expect identical fermentation from two types of yeast. I’ve even had instances where I pitch the same type of yeast and one takes off faster than the other; probably due to package age or handling or something.[/quote]
Agree completely. The differences are due to strain and pitch rate more than liquid versus dry.

The liquid yeasts typically need a starter to be put into a pitchable state for any beer above about 1.040. The dry yeasts perform even better, however, if they are rehydrated. The sheer number of cells in a dry yeast packet far outnumber the cells in a liquid yeast smack pack or vial. And at the beer party numbers count. Gravities and temperature can affect things further based on yeast strain, of course, but generally speaking, on the first pitch, the dry yeast packets are better than the liquid yeasts vials/smackers on a single unit basis.

I’ve noticed that store-bought liquid yeast tends to be really laggy if I don’t use a starter. Much shorter lag times with a starter. Much shorter lag times with yeast cake that’s repitched without a starter, too, as long as hasn’t spent more than a couple weeks in the fridge.

My assumption’s always been that it’s that liquid yeast is pretty well half-starved after a month or two of sitting around at the LHBS.

Rehydrated dry yeast is a party animal.