safe to mix US-04 and US-05?

[Paradigm]

Ok, so generally what I do when I order recipes is calculate my dry packs of yeast to have a really low viability (50%) on Mr Malty and then order to the nearest packet. For a 1.065 OG I'll need 2.3 11.5g packs if the viability is 50%, so I'm confident that 2 will be enough.

For some bizzaro reason both my packs are super-low viability would it be OK to add the remaining as US-05? I have about half a packet in the freezer from my last brew. I often see US-04 and 05 as options for the same beer and they seem to be pretty similiar.

The beer is a heavy-citra-hop IPA.

 

[eastoak]

unless you are buying really old yeast there is no reason to assume that they have a viability of 50 %, 1 packet of US-05 is plenty for a 1.065 beer. as far as mixing those 2 yeasts, there is nothing wrong with doing that.

 

[Foosier]

"Safe" is really the wrong word to use. Sure it is safe. It is just yeast. Do you need to do it? No. As eastoak said, one sachet of dry is usually enough. I would not assume they are 50% viable either.

 

[GreatDayBeer]

I've been making a 1.067 export stout for the last couple of years that uses one pack of S-04 and one pack of US-05. It comes out very nice so those two(2) seem to play well together. Started out that way because that was all I had on hand at the time. The results were great soI keep making it using both.

 

[kh54s10]

How old is the yeast. If they were well stored (refrigerator) they should lose very little viability.

From Fermentis: How long does the yeast last in storage?
The sachets are stable for two years from date of manufacture with no significant loss of viability and fermentation activity. Fermentis dry yeast should be stored below 10C to ensure optimum fermentation performance.

 

[Paradigm]

Hi all,

Thanks for all the reminders, but I'm very familiar with the viability of dry yeast packets. I did specifically mention that my caluculations are "in case" measures. I understand 50% viability is unlikely, but I'd rather have extra yeast I need to store rather than too little.

 

[hunter_le five]

My buddy tried mixing US-04 and US-05 one time, and it did not end well. So much blood. They still can't find all the pieces. May he RIP. Stay safe, and be careful.

 

[eastoak]

Hi all,

Thanks for all the reminders, but I'm very familiar with the viability of dry yeast packets. I did specifically mention that my caluculations are "in case" measures. I understand 50% viability is unlikely, but I'd rather have extra yeast I need to store rather than too little.

we hear you but what you are doing is certainly not best practice. a correct yeast pitch is, along with temperature control, the most important part of brewing beer. calculate how much yeast you need and pitch that amount. calculating viability at some random percentage is not helping you make better beer.

 

[jmendez29]

we hear you but what you are doing is certainly not best practice. a correct yeast pitch is, along with temperature control, the most important part of brewing beer. calculate how much yeast you need and pitch that amount. calculating viability at some random percentage is not helping you make better beer.

And it isn't necessarily making worse beer now, is it? There are plenty of brewers who use combinations of yeast to achieve a certain flavor profile so what he's asking isn't exactly taboo. Also understand what he's been saying repeatedly, and that is that he is assuming a worst case scenario.

Paradigm. I can't say how it will turn out, but I suspect you got it right. I'm sure the beer will be just fine. But unless it turns out downright spectacular, I probably would bother washing and reusing the yeast from it. At some point, you have to assume that you have no control over the ratio of US04 to US05. And with that assumption, you really don't know what yeast you have at that point. So as an emergency backup, I personally don't see a problem with it but if you can plan ahead, why risk it? Others may see differently....

 

[eastoak]

And it isn't necessarily making worse beer now, is it? There are plenty of brewers who use combinations of yeast to achieve a certain flavor profile so what he's asking isn't exactly taboo. Also understand what he's been saying repeatedly, and that is that he is assuming a worst case scenario.

yeah, i was talking about pitch rates not mixing yeasts. when i read his post about worst case scenarios i think he was also talking about pitch rates.

 

[jmendez29]

yeah, i was talking about pitch rates not mixing yeasts. when i read his post about worst case scenarios i think he was also talking about pitch rates.

Yup. It sounds like he's got a pretty good grasp on that as well. His initial post talks about the prospect of ordering "too little" on the assumption that the yeast is of absurdly low viability. Not like he's asking if a single pack will cover a 1.125 OG but if the recommended 2.3 packs with a viability of 50% would be covered by 2 packs of a real world 75% viability(or higher). You even used one of his posts in yours...

Hi all,

Thanks for all the reminders, but I'm very familiar with the viability of dry yeast packets. I did specifically mention that my caluculations are "in case" measures. I understand 50% viability is unlikely, but I'd rather have extra yeast I need to store rather than too little.

But back to the point, he was asking if it would be ok to mix yeasts, that's all. You even answered it on your first post in the thread.

 

[eastoak]

Yup. It sounds like he's got a pretty good grasp on that as well. His initial post talks about the prospect of ordering "too little" on the assumption that the yeast is of absurdly low viability. Not like he's asking if a single pack will cover a 1.125 OG but if the recommended 2.3 packs with a viability of 50% would be covered by 2 packs of a real world 75% viability(or higher). You even used one of his posts in yours...



But back to the point, he was asking if it would be ok to mix yeasts, that's all. You even answered it on your first post in the thread.

none of that makes sense to me but it doesn't matter anyway.