Stepping Up Yeast

[Saisonator]

Hi,
I salvaged this yeast from a bottle of Fullers 1845 about 3 months ago.
It is in a 500ml bottle so it is about 300ml and was stepped up in the bottle in two stages.
I wondered how you would go about getting it to a good pitch rate for 24 litres of 1.050 gravity beer, plus a reasonable overbuild to harvest for future use.
I have a 3 litre flask and stir plate, also how long do you think it will take?
Cheers

 

[Saisonator]

Looking at various calculators I am thinking -
Pour off spent wort/beer from the bottle and decant yeast sludge into 0.5 litres of 1.036 wort, put on stir plate for 2 or three days.
Pitch this into 1.75 litres of 1.040 wort until fermentation ceases, pour off 0.5 litres into a plastic bottle for future use.
Cold crash and pour the rest of the sludge into sanitised jar and refrigerate, use within a week.

 

[Zephyr259]

I am planning on doing this at some point, I asked some advice of @jceg316 who'd meantioned doing it in a thread. Here's his response.

Spoiler

Before drinking, put the bottles in the fridge for a while to 'cold crash' them. This gets all the yeast to the bottom of the bottle, and when you pour it the yeast won't mix in to the beer as well.

make a small starter, about 250 ml of 1.020 wort. When making starters, using 10g of DME to 100ml of water will make a starter of 1.040, so you just need to halve the DME amount.

Before opening the bottle, spray the lid and bottle opener with starsan. Open, decant the beer into the glass but leave an inch or so of beer at the bottom. Swirl the remaining beer in the bottle to mix it up with the yeast and pour it into your starter which should be at room temperature. Do this with 2 or 3 bottles.

After a couple of days, make 500ml of 1040 starter and pour it into the existing starter with the yeast. Wait a couple of days for the yeast to ferment out that starter and repeat again if you need a bigger starter.

Pitch the yeast into your beer.

There are some videos on Youtube with instructions on culturing up yeast, but most of them seem to be cukturing some sort of American ale yeast. It would be a good idea to watch a couple of these videos, but I would recommend adding in the 1020 step which a lot miss out. American ale yeast is a lot less fussy than Belgian yeasts, and Belgian yeasts need more care over them.

I ran your number and looks like you have enough yeast for that brew and to store 100 billion cells for future. My spreadsheet says to harvest 300 mls for storage.

Good luck.

 

[jceg316]

@Saisonator you say you want to grow more for future use, have you considered taking the remains of the fermenter when the beer is finished in primary? You'll get several jars full from there.

Also, it might be better to store the yeast in glass jars than plastic bottles. Plastic isn't great for long term storage, so I hear.