Harvesting Yeast

I am planning on harvesting some of the yeast from the secondary when I get ready to bottle. I used dry yeast to start with. The package said to NOT make a starter or rehydrate. If I reuse the this yeast in the future should I make a starter make a starter?

First off, I wouldn't harvest any yeast from the secondary. While it can be done, you'll have a different fermentation than you had for the original batch. For instance the harvested yeast will be more attenuative but much less floculant.

As for starters, I use a starter if I am pitching yeast that has been harvested more than a week ago. The viability of yeast is constantly decreasing over time, fairly rapidly when kept in the fridge.

Further, I think it's not worth a brewer's time to harvest yeast that is $3 for a brand new pack of dry yeast.

It was my understanding that if you are going to reuse yeast, that you should get it from the secondary. I was also under the impression that yeast can last a long time if refrigerated.

uechikid said:

It was my understanding that if you are going to reuse yeast, that you should get it from the secondary. I was also under the impression that yeast can last a long time if refrigerated.

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You certainly can keep it a long time! I have used yeast that was in my fridge for a year or so, with good results.

I wouldn't reuse yeast from the secondary, though. That is the least flocculant, most stressed yeast of all. It's been sitting in an alcohol rich environment longer, too.

Yeast from the primary is fine to use. The yeast in the secondary will be "cleaner", but a quick yeast washing takes care of any trub from the yeast in primary.

My above post should've read "fairly rapidly EVEN when kept in fridge". The viability is still declining. Check out Mr. Malty's pitch rate calculator to get a better understanding of this decline.

As for the secondary, think about the yeast that is in there. Those are the yeasts that didn't floc out with the majority of the healthy yeast. If you capture those, you are also capturing their traits. In an ideal harvest you will gather yeast from either the top by top cropping during fermentation or by selecting yeast from the middle layer of the yeast cake in the primary. Selecting the middle layer gives you an average of that yeast's attenuation, thus providing yeast that will give you a fermentation most similar to your original batch.

Long story short, selecting from the secondary will give you a more dry and more cloudy beer.

Thanks. From the primary and washed it is.