Negatives from mixing different yeast?

[clydo]

What would be an expected result if I were to mix a pack of s-04 dry yeast and White Labs Irish Ale Yeast? The reason I ask is I ordered from AHS 4 days ago and it's arrived today (sitting on my porch in the GA heat while I'm at work.) I'm worried my WL yeast (packed w/cold pack) may not have survived but I have an extra pack of S-04 at home.

If the WL vial is hot, should I pitch them both together or wait to see if the WL yeast shows signs fermentation?

 

[bja]

Make a starter and find out if it's good.

 

[betarhoalphadelta]

The two yeasts are not *phenomenally* different, so I wouldn't expect any negative interactions. Essentially you'll have a flavor profile likely somewhere in between the two, and probably closer to the S-04 because you'll have a higher cell count.

About the only time you'd see a *negative* from mixing yeasts might be with two yeasts that have different characteristics at different temperatures. For example, I occasionally use a belgian yeast from a local brewery, and the brewer has told me that when fermenting below ~75 degrees, it puts out a lot of sulfur. I wouldn't want to toss a pack of US-05 in there with the yeast and ferment hot, as the US-05 might throw off esters I don't want at >75 degree temps.

However, I just brewed a Gose with a mix of US-05 and WLP300 (Bavarian Hefe), and fermented at 62 degrees. I wanted to get *some* of the flavor profile of the WLP300, but not an overwhelming amount, so by combining the yeast I should be somewhere in between the neutral US-05 and the clove hefe characteristic of the WLP300.