Yeast starter-a mistake?

Share your experiences of using brewing yeast.
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guypettigrew
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Yeast starter-a mistake?

Post by guypettigrew » Thu Feb 02, 2017 10:31 pm

Long post, apologies, but it didn't seem possible to make it shorter.

In two days I'll be brewing a beer which I want to pitch with my harvested White Labs 005.

The yeast, from The Malt Miller, was first used on October 13th 2016. It's been harvested and used three times since then. The next brew would be the fifth time it's been pitched.

It's harvested from the bottom valve of my SS Brewtech seven gallon chronical. I simply run the yeast off into a sanitised container. It's like this one, except it's 0.5 litres. There's a thick layer of yeast in the container, covered by beer. It's stored in the 'fridge until needed.

Usually the top of the container begins to pop up after a day or so, indicating the yeast is alive and well. I release the pressure every 12 hours or so for the first few days then it settles down. Apparently it's not good for yeast to be under pressure. It stays in the 'fridge until needed then it's pitched directly into the brew. Signs of fermentation are usually seen after a few hours.

This time the yeast didn't pop the top of the container. It made me wonder if the slurry in the pot was mostly dead yeast. If this was the case then pitching direct would mean there was a chance the fermentation would start too late to stop wild yeast and bacteria from spoiling the brew. This has happened to me before and it's really annoying having to chuck 20+ litres of beer down the drain.

Making a starter seemed the safest thing to do. If the starter didn't start, or smelled awful, then I'd use my back up dried yeast on brewday.

This was my first attempt at a starter, other than one a while ago which was a disaster!

A litre of approx. 1.040 was made using dried malt extract boiled with tap water and a tiny (0.05g) bit of yeast nutrient. it was boiled for about 10 minutes, poured into a sanitised Erlemyer flask and cooled to just over 20C. The yeast slurry from the container, minus the beer on top, was tipped into the flask.

After half an hour there was krausen. Which got to half a litre above the liquid. Now, about four hours later, the krausen has died down to a 1cm layer.

Suggests to me the yeast was good and could have been pitched direct. Ah well, we are where we are.

Thanks for reading this far. Here comes the question. What should I do with the flask? Leave it at room temperature until Saturday? It won't fit in the 'fridge, but should it go somewhere cool, like the garage--about 14C?

The last thing I want is to get to brewday and discover I've killed the yeast by starting it too soon and starving it to death.

Thanks.

Guy

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Dennis King
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Re: Yeast starter-a mistake?

Post by Dennis King » Thu Feb 02, 2017 11:15 pm

I have always either pitched the whole starter at high krausen or let ferment out and settle, around 3 to 4 days. When using the second option I always take a litre of the wort from the brew 15 mins into boil and crash cool to 20c then pour off the spent yeast from the starter and add the fresh wort. By the time the boil is completed and the wort cooled the fresh starter is up and running and chomping at the bit to do it's work.

guypettigrew
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Re: Yeast starter-a mistake?

Post by guypettigrew » Thu Feb 02, 2017 11:54 pm

Excellent idea, thanks Dennis.

Guy

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