Yeast Harvesting vs Splitting Starter

I have seen a few posts lately where yeast harvesting has been touched on as part of another topic. I have read some materials on the how of harvesting, but have only done it a single time. The reason, I simply by a new vial of yeast, grow in a starter, then split evenly between 3 small mason jars. I then build a starter later using one of the mason jars. So much easier than trying to harvest and/or wash yeast, especially since I mainly do IPAs with heavy dry hopping.

The main part of the harvesting that made me start to think about this technique, was how future generations of yeast can sometimes be "better". Maybe more inclined to survive higher gravity, produce more esters, ect. Do these types of changes from future generations only come from harvesting yeast that was used to complete a full batch of wort vs splitting a starter like I do.

I already have my next 3 batches lined up, which will be the same NEIPA recipe with some small variations for experimentation. I will be using London III and have seen a few people state they get fruitier esters with future generations of yeast and fruity is what I like.

Thoughts?

 

Well the way of splitting it 3 ways is a bit of a guesstimate, but has always worked for me thus far. To be clear, I build a starter and split it three ways, but then make another starter with one of the jars when ready to brew. So I'm not splitting it and just using a 3rd of the first starter.

The next statement is based on using a pitch rate calculator like on brewer's friend for a 1.05 OG and 5.5g batch. Leaving Mfg date as 0 days old just for the argument since this would depend on what you actually buy.

If you start with a 100 billion cells from a standard liquid vial and build a 3L starter, on a stir plate, the calculator spits out roughly 500 billion count when complete. Split this 3 ways, you get 166 billion per jar. Then start the calculator over, but adjust vials to 1.6. The result of the next starter would be an ending cell count of almost 600 billion. Well above the required amount.

Based on the above math you could split it 4 ways really, but since most yeast I receive it older than 0 days and this estimates the viabillity much lower I always chose to go with a three way split. Build up starter one, put in fridge to crash yeast, decant and split remaining yeast into small jars.

 

So far the oldest jar I have used was 3-4 months old and still hit my target attenuation. After decanting and splitting into jars I top off with boiled distilled water.

I have yet to build and split a jar a second time, but I have been thinking about it.

 

I read threads where it goes both ways, just the way I've done it. I could leaving a bit a juice behind when I decent to fill the jars to the top as well. Probably easier than doing the extra step of boiling and chilling distilled water.