Should i reuse it

Ok I made what I would say is a bad beer.
6# pilsner
3# 2 row
1# white wheat
.5# Munich
.5# flaked oats hops not listed
150 mash. /mash ph was between 5-5.2 mash water was RO with 1.8 tsp gypsum 1 tsp CI .
now the beer I got went down to 1.010 and no sing of an infection but it dose have off flavors like plastic and maybe some dms but these may clear up some in the bottles after some time. either way I’m planning to brew again using part of the notty yeast cake. my worries is that the yeast may give me the same results with a different recipe. does yeast from a so so beer have an impact on the next brew or am I over thinking this.
PS I have almost a quart of washed yeast from that batch.

First off not knowing exactly what gave you your off flavor why risk the same in your next batch of beer. Yeast is cheap. A lot cheaper than wasting another batch of beer. If was dms boil longer and cool your wort as fast as you you can after your boil is through. Also pitch your yeast at the proper temp and ferment at proper temps will help you not have off flavors

How did you measure pH? Where did you get your RO water? Medicinal/plastic flavors can be caused by improper pH or chlorine in water. I will say that a mash pH of 5 is low and depending on how you sparge could have dropped this lower causing more problems.

included with your purchase of yeast for the next batch should be a package of camden tabs. I have had one band-aid beer in +/- 60 batches and it was enough for me to camdenize every batch to drop out chloramines/chlorine. By the way I’ve been using the same $4.95 package since that beer and I am about halfway through the package.

I’d say dump it. Penny-wise, pound foolish otherwise.

yes the low PH is a good observation. I’ve decided just to do a party gyile and use to different yeasts. one with the notty cake and the other with 05 since it rarely gives off flavors for me. ps I use Camden tabs for a while now.

If by notty you mean Nottingham dry yeast, why bother. It is cheap enough and unless it is a very big beer should take off and ferment nicely. So I would not unless you are brewing soon and it’s not feasible to get a new packet of Nottignham.