Re-pitch different strain, why?

[estebanuri]

Hi everyone,
I've seen some recipes that for secondary fermentation use a strain of yeast different from the primary.
Does it make sense to do this? Why?

If final gravity has reached, there's no more sugar to ferment...
If we are re-pitching a second strain with some extra sugar, how can be sure that the yeast that will work is the second one and not the first one?

If we are looking for complexity can't we just combine yeasts since the primary?

Thanks!

 

[madscientist451]

It depends on what you are trying to achieve. Can you put in the specific recipe you are talking about?

 

[thehaze]

There are always sugars to ferment, but it depends on the yeast you have used. Most sacch yeast will not eat all sugars. Adding brett will eat more and lower the FG.

 

[Gravity]

I would not combine yeast unless you know specifically what you want. Repitching the same yeast is cool, a different yeast needs more thought. Your recipe and intended flavors/outcome would help

 

[Kent88]

For a barleywine (that had been primarily fermented with a white labs high gravity strain) we bottled 6 months ago a friend of mine and I added just a little dry yeast to each bottle because it had been sitting for 6 months and if I remember correctly it had an OG above 1.090. Didn't add a ton, didn't want any new flavors from it (including autolysis), but wanted just enough that it might help prime the bottle.

It worked so well I did almost the same thing with my Belgian Dark Strong Ale. I used Wyeast 3822PC primarily, and at bottling I added just a little dry saison yeast. Not trying to get new flavors, just want to carbonate a beer where the original pitch of yeast should have all settled out and gone dormant to the point where I might not get much from it.

I've heard that adding dry yeast directly from the pack to a high-alcohol beer doesn't do much, but I think the earliest I sampled the barleywine was 6 weeks after bottling, and I don't plan to crack into the Belgian Ale for a few months, plenty of time for whatever yeasts might survive to do their thing.

I remember NB had a carbination drop/tab that had new yeast in with the sugar, but last I checked I couldn't find that.

 

[estebanuri]

Sure, for instance this recipe. http://www.candisyrup.com/uploads/6/0/3/5/6035776/gulden_draak_9000_clone_-_040.pdf
I think it's my favorite beer ever tasted.

But there are also many other recipes which add a second yeast for secondary stage or for priming... Some folks say they use Champagne yeast for this step.

 

[kingwood-kid]

Sure, for instance this recipe. http://www.candisyrup.com/uploads/6/0/3/5/6035776/gulden_draak_9000_clone_-_040.pdf
I think it's my favorite beer ever tasted.

But there are also many other recipes which add a second yeast for secondary stage or for priming... Some folks say they use Champagne yeast for this step.

For that recipe, I have no idea. If it's in secondary, I could see using one yeast for flavor and the second to insure fermentation gets to the preferred dryness. For priming, people will often use a yeast that is low-attenuating (so it only eats the priming sugar and doesn't overcarbonate), a strong flocculator and tolerant of high-alcohol and reduced nutrients.

 

[Calder]

The second yeast is a waste in that recipe. The Bastogne yeast has a higher alcohol tolerance, a higher attenuation, and more flavor. There will be nothing left for the Forbidden Fruit.

Sometimes there are legitimate reasons for using a second yeast:
- To finish fermentation of a lower alcohol tolerant yeast, where you want the flavor characteristics of the initial yeast.
- For priming of a high alcohol brew. Champagne yeast is often used as it has high alcohol tolerance and generally only ferments the simple sugars used for priming, and not the complex sugars left by the original yeast.

I see no reason for the second yeast in the linked recipe.