Re-use yeast from off taste previous batch?????

I brewed an all-grain fat tire knock off and possibly first stage fermented at a bit high temp (possibly). The beer tastes off. I typically use the yeast again and again for 3 to 4 batches continuously. If the first batch is off (tastes and smells funny) can I put the second batch of wort into the leftover trub from the first batch without the same bad result. I intend to try the second batch with a lower first stage ferment temp. Also, would it help to leave the sediment in the bottom behind and only use the bottom 1" of liquid and yeast into a new better bottle????? Thanks o great ONES. Need to do second batch soon.

I suppose one would need to know what was "off" about the first batch in order to give a well reasoned answer. Regardless, I would not mess with repitching in that case. Yeast is not obscenely expensive so why not pitch a new pack? At least you will not have wasted effort.

Do you typically repitch two or three batches onto the same used yeast cake?

I typically repitch 3-4 batches on the same cake with no problems. I typically use White labs. This time my LHBS gave me so out of date fat tire yeast. I figured that even if it was out of date, if I did a starter and a second starter I could get the yeast count up high enough. I used 2 out of date WY packs and my starter was extreemly active.

Tech211 said:

I suppose one would need to know what was "off" about the first batch in order to give a well reasoned answer. Regardless, I would not mess with repitching in that case. Yeast is not obscenely expensive so why not pitch a new pack? At least you will not have wasted effort.

Do you typically repitch two or three batches onto the same used yeast cake?

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I agree with Tech. I used to reuse yeast and never had any problems with contamination, but with the price of yeast, why not buy a fresh, guaranteed sterile pack?

I agree also and will use new yeast, but the yeast was sterile. I boiled the starter, very clean clean room, bombarded with ozone machine regularly. Washed the Wy packet in iodine solution before opening. It it is just the overtemp from first batch will second batch at correct temp be ok? Or will existing off yeast produce off flavor at lower temp? Never had this problem before in 40+ batches AG.

avidhomebrewer said:

I agree with Tech. I used to reuse yeast and never had any problems with contamination, but with the price of yeast, why not buy a fresh, guaranteed sterile pack?

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How much is it going to bother you to make another "off tasting" beer? And why aren't you yeast ranching? Your brief description of your very clean clean room sounds like you are only about a half step away from yeast ranching. Just think, all kinds of flasks, slant tubes and petrie dishes to play with too! Yer gonna need a microscope too!...and...ahem, please excuse the outburst.

I'd use new yeast.

If you have even slightest suspitions about quality of yeast slurry, don't use it.

Piotr said:

If you have even slightest suspitions about quality of yeast slurry, don't use it.

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Yeah...if there is an off taste in this batch, there a high likely hood that that would transfer to the second batch...Why risk it?

If you are sure about the only problem being the warm ferment, then reuse the yeast. It would be no different than making a starter for a lager at room tempertures. You just grew yeast.

If you're not sure, then use fresh yeast.

I did spend some time a few years ago studying yeast farming. Glyc*** and all the fun chemicals. At that point I decided that I would just re-use yeast for consecutive similar batches and try to get the most out of each pitch. The two times that I did farm my yeast I was never sure if the middle I was siphoning off was the yeast-ty-est section. It was a fun experiment, but I decided that I would just use new yeast and pitch for consecutive batches.

IowaHarry said:

How much is it going to bother you to make another "off tasting" beer? And why aren't you yeast ranching? Your brief description of your very clean clean room sounds like you are only about a half step away from yeast ranching. Just think, all kinds of flasks, slant tubes and petrie dishes to play with too! Yer gonna need a microscope too!...and...ahem, please excuse the outburst.

I'd use new yeast.

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Do you just dump new wort on the old yeast cake? I have done that a number of times and yee haa, that is one vigorous ferment. A blow off tube is a must for that application.

Ditto for new yeast. Maybe it wouldn't matter, but why risk it?

Plus, if you used a Belgian strain for the fat tire, the growth phase is important. Pitching on a Belgian cake will change the results.