Is My WLP400 Yeast Infected?

[Jezz]

I did a Belgian Wit brewday on Monday. I had a bit of a surprise when I pitched my yeast. I used White Labs WLP400 because I have used it many times before when brewing Wits and had amazing results with it. It is usually an off white creamy consistency and smells lovely and yeasty. Each time I've used it before it's activity has been voracious, usually bubbling away through the blowout tube within 3 to 4 hours of pitching and always producing excellent flavours in the finished beer.

This time however was different. When I poured the yeast from the pouch it was a brown liquid. I have never seen it look like that before! Also when the pouch was empty I had a sniff of it and it smelt kind of vinegary. The usual strong yeasty smell was not present. It has been in for about 42 hours now and not a sign of any activity. The sg has not changed at all. Basically it appears to be doing nothing. I called the supplier I bought it from and they said that it was normal for it to be brown sometimes & to smell vinegary. That certainly has never been my experience. They said not to worry as it will be OK.

I am now wondering is the yeast dead and so if nothing happens in the next 24 hours or so I will just be able to repitch with some fresh yeast or is it actually infected and I'll have to dump the whole batch? Has anyone had a similar experience with White Labs liquid yeast? Am I just worrying about nothing? Any advice/thoughts would be most welcome. Cheers.

 

[jambop]

I did a Belgian Wit brewday on Monday. I had a bit of a surprise when I pitched my yeast. I used White Labs WLP400 because I have used it many times before when brewing Wits and had amazing results with it. It is usually an off white creamy consistency and smells lovely and yeasty. Each time I've used it before it's activity has been voracious, usually bubbling away through the blowout tube within 3 to 4 hours of pitching and always producing excellent flavours in the finished beer.

This time however was different. When I poured the yeast from the pouch it was a brown liquid. I have never seen it look like that before! Also when the pouch was empty I had a sniff of it and it smelt kind of vinegary. The usual strong yeasty smell was not present. It has been in for about 42 hours now and not a sign of any activity. The sg has not changed at all. Basically it appears to be doing nothing. I called the supplier I bought it from and they said that it was normal for it to be brown sometimes & to smell vinegary. That certainly has never been my experience. They said not to worry as it will be OK.

I am now wondering is the yeast dead and so if nothing happens in the next 24 hours or so I will just be able to repitch with some fresh yeast or is it actually infected and I'll have to dump the whole batch? Has anyone had a similar experience with White Labs liquid yeast? Am I just worrying about nothing? Any advice/thoughts would be most welcome. Cheers.

Suppliers will say anything over the phone The thing with liquid yeast is the use by date and how it was stored. Just my opinion but I would say any White labs product that has been stored properly and is still in date should be good IF it has been stored properly. From your side you have invetsed a lot in terms of cost and time into the beer ... the yeast supplier will not want to share your costs if he can help it. edit
I know that it is not always required but I don't wonder that there is no harm in having the yeast made into a starter before pitching to make sure it is ready to go at pitching time... it could be a brew saver! Liquid yeasts are great but then again I would say that dried yeasts are in my experience very reliable at less cost and just like liquid yeasts they can be harvested for reuse.

 

[An Ankoù]

I did a Belgian Wit brewday on Monday. I had a bit of a surprise when I pitched my yeast. I used White Labs WLP400 because I have used it many times before when brewing Wits and had amazing results with it. It is usually an off white creamy consistency and smells lovely and yeasty. Each time I've used it before it's activity has been voracious, usually bubbling away through the blowout tube within 3 to 4 hours of pitching and always producing excellent flavours in the finished beer.

This time however was different. When I poured the yeast from the pouch it was a brown liquid. I have never seen it look like that before! Also when the pouch was empty I had a sniff of it and it smelt kind of vinegary. The usual strong yeasty smell was not present. It has been in for about 42 hours now and not a sign of any activity. The sg has not changed at all. Basically it appears to be doing nothing. I called the supplier I bought it from and they said that it was normal for it to be brown sometimes & to smell vinegary. That certainly has never been my experience. They said not to worry as it will be OK.

I am now wondering is the yeast dead and so if nothing happens in the next 24 hours or so I will just be able to repitch with some fresh yeast or is it actually infected and I'll have to dump the whole batch? Has anyone had a similar experience with White Labs liquid yeast? Am I just worrying about nothing? Any advice/thoughts would be most welcome. Cheers.

It doesn't sound good, I have to say. But you've got nothing to lose by leaving it until tomorrow morning. Try and keep t warm, too. 19-23 C is the recommended temperature.

 

[MashBag]

I would get some more yeast in it QUICKLY. ASAP.

It won't be the same, but it will save the day, if you act quickly.

You also what good temp control.

DO NOT AERATE. If you sprinkle, wait 10, sir gently.

 

[jambop]

I would get some more yeast in it QUICKLY. ASAP.

It won't be the same, but it will save the day, if you act quickly.

You also what good temp control.

DO NOT AERATE. If you sprinkle, wait 10, sir gently.

To be honest I have tried liquid yeast cultures and they are good but for me well over priced and ultimately you are at the mercy of the supplier keeping them in the correct conditions, if they get that wrong you are buying rubbish and at the price the are asking that is madness. My advice to anybody using liquid yeast cultures is to sub culture your new yeast just before you pitch it. That would involve making half a dozen or so culture tubes sloped with a malt agar medium . These can the be streaked with the new culture and stored in the fridge for at least six months and still remain good. These can be built up into a starter culture when required. This is not a difficult procedure but having said that I have vast experience in this type of work not everybody has.
Honestly for most brewers, and I include myself, dried yeast is a much easier, reliable and cost effective way of fermenting your wort. The yeast can be harvested if you want in just the same way you would a liquid yeast.