When NOT to wash yeast?

Hi!

I recently had some problems with my starter making that caused my beer to take about 5 weeks to ferment. Basically, I underpitched. For details, go here: https://www.homebrewtalk.com/f163/am-i-doing-something-wrong-my-yeast-starters-237788/

Anyway, a Wyeast pack costs me about 15-20$ when I order them online because of shipping. If I buy more than one, then shipping per unit goes does, but it's still expensive. My LHBS is unreliable when it comes to what they carry.

So anyway, I would like to wash my yeast to bring my per-batch cost down, but I don't know if this yeast is ruined or not. Assuming this beer turns out OK (not bottled yet), should I wash the yeast (and make a good starter later), or just dump it and call it a learning experience?

Thanks!

dump. Although expensive, you only want to wash yeast that did well for you. In this case it seems as though it took forever and personally I would not risk a finished beer with a higher gravity than im shooting for just to save a few bucks on yeast- but hey thats just me. In your case i would make slants in agar tubes and save them, repopulating them in starters when you need them. Its fairly east and if your technique is good you shouldn't worry about contamination. Thats how I used to keep many different strains of yeast around as well as have some fun and save money. You just need a bit of fridge space...

good luck

Wash it and call it a learning experience. If it does the same thing again with your next beer, you know it's the yeast (and if it's not giving you the results you want, pitch it and start over).