Reculturing yeast question

timmy · Post by **timmy** » Tuesday Jun 05, 2007 6:57 pm

Hi all,

I'm trying to reculture some CSA yeast harvested from 2 longies of the good stuff drunk over the weekend. I've boiled up the 100g LDME in 1L water and pitched both it and the dregs into a 2L PET bottle and fitted an airlock. I've only previously made starters using liquid yeasts and they go off like a cracker. This one has no krausen after a day at room temps but is bubbling ever so slowly from the airlock. Have I tried to step up to a too-large a volume? If so, will it still be any good? Failing all that, how different is the normal Coopers kit yeast to that in the CSA bottles?

Cheers,
Tim

geoffclifton · Post by **geoffclifton** » Tuesday Jun 05, 2007 7:12 pm

Coopers recommend using some dex so I may have used 50/50 dex and ldme. Your 100g/L is spot on a 1040 wort using BC http://www.brewcraft.com.au/wa.asp?idWe ... etails=172
so I don't think you have a problem if you wait a few days and keep the temp around 20*.
Cheers, Geoff.

shane_vor · Post by **shane_vor** » Tuesday Jun 05, 2007 7:21 pm

The 'bottle dregs' recoveries I've done have tended to take off slowly.
I get into all kinds of trouble from the missus when I sit on the lounge cuddling a culture to keep it nice and warm...

ryan · Post by **ryan** » Tuesday Jun 05, 2007 7:34 pm

Any Coopers recultures I`ve done have ALWAYS taken 24/36 hours to get to pitching stage. That`s using the yeast dregs from 2 CPA stubbies. You may be better to start with say a 200/400 mill. starter and feed it up from there.

KEG · Post by **KEG** » Tuesday Jun 05, 2007 10:58 pm

i wouldn't use any dex in a starter at all, geoffclifton..

rwh · Post by **rwh** » Wednesday Jun 06, 2007 12:15 am

Yep, all malt, and don't be surprised if it takes up to 48 hours to get to full krausen.

timmy · Post by **timmy** » Wednesday Jun 06, 2007 7:47 am

Thanks for the responses.

I put the bottle next to the ducted heater vents last night and this morning it is starting to bubble but still no krausen to speak of. Will be patient....

geoffclifton · Post by **geoffclifton** » Wednesday Jun 06, 2007 8:52 am

Hi RWH & KEG.

I read somewhere that a starter should be made on a wort that matches as closely as possible the wort that it will be pitched into so that the yeast breeds up for that sugar environment. As Coopers recommend the use of some dex with their kits I presumed it should also be present in the starter.

I do of course accept your experienced comment but is there any further explanation as to why the dex should be left out of the starter?

Cheers, Geoff.

rwh · Post by **rwh** » Wednesday Jun 06, 2007 10:35 am

Well, we're getting into the realm of yeast nutrition, and I wouldn't call myself an expert on this. However, from what reading I've done, barley malt provides all of the nutritional requirements of yeast (FAN, some elemental nutrients, some fatty acids), whereas simple sugars do not, which means that the yeast must manufacture what nutrients they can from sugar, so that they must work harder and don't grow as fast.

Now, there's a school of thought that you can supplement some adjuncts (typically up to 20%) into your wort without jeopardising the yeast's nutrition, because the barley malt provides some excess of these nutrients. You need to be careful with this though as it's based on all-grain technique, and some nutrients (FAN in particular) are lost during the dehydration process and long storage times associated with our dried and liquid malt extracts.

Certainly if you can use the same recipe to make the starter as you have in your beer wort the yeast will need to do less to become accustomed to the conditions there, and that's really an optimal situation, but the next best thing is an all-malt starter (and almost all my beers are all-malt so I win in on both counts

).

timmy · Post by **timmy** » Saturday Jun 09, 2007 8:30 am

An update on this one.

I haven't seen any krausen in the starter bottle but it appears to have fermented out (FG ~1005). But there is a slight smell of thinners when I open the bottle to sniff it, and the taste has a strange aftertaste. I'm now concerned that I have an infection. Has anyone else noticed this when culturing Coopers yeasts?

Assuming I'm OK, I'll probably need to step it up before I pitch. Given that the starter is already a litre, I was thinking of:
- cooling the starter to encourage the good stuff to settle at the bottom
- pour of the bulk of the liquid
- throw in another 1L of 1040 wort.
Is this about right?

Cheers,

Tim

KEG · Post by **KEG** » Saturday Jun 09, 2007 11:32 am

i'd do that minus the cooling if possible. keep the yeast's temperature stable.

Noodles · Post by **Noodles** » Tuesday Aug 21, 2007 2:54 pm

This is the easiest method i've seen of making a starter. Can anyone experienced in making starters tell me why I should or shouldn't use the following method?

When your brew us at the height of its fermentation, usually around the three to four day mark, tap off 600-700 ml of the fermenting beer into a sterilized soft drink bottle (plastic) and seal it tight. Allow this to ferment a further 12-24 hours and then put the bottle in your fridge. It is important to make sure that the bottle has plenty of pressure in it when it is placed in the fridge. The cold will put the yeast on hold until you are ready to use it again.
To reactivate the yeast it is simply a matter of taking the bottle out of the fridge one day before you want to brew, giving it a good shake and allowing it to stand in a warm, dark spot. When the contents of the bottle start to ferment it is ready to add to your next brew. This procedure can be repeated two to three times before the yeast may mutate and affect the flavour of the brew.

ryan · Post by **ryan** » Tuesday Aug 21, 2007 3:02 pm

That would be as good a way as any. I personally use the method of harvesting the yeast slurry from the primary or secondary ferment, depending on which is cleaner-ie, least hop and grain debris in it. But yours will work fine.

Noodles · Post by **Noodles** » Tuesday Aug 21, 2007 3:07 pm

Thanks Ryan. Just a quick follow up question. Would I only use this method if i've used a liquid yeast or is it worth making starters from dry yeasts as well (not kit yeasts, but saflafer or safale)?

rwh · Post by **rwh** » Tuesday Aug 21, 2007 3:09 pm

You can try it. The only bit I don't like is putting the starter in the fridge before it's completely fermented out. Also waiting until it's high-pressure. If I was you, I'd let it ferment out completely before refrigerating, in order to avoid blowing up your fridge.

I personally don't think it's worth making starters for dried yeast. It's a cost-benefit equation. When you can have a cheap sachet that's guaranteed infection-free, is it worth the risk of losing a batch if you make your own starter? Probably depends how clean you are.

Noodles · Post by **Noodles** » Tuesday Aug 21, 2007 3:11 pm

So your method would require an airlock in the top of the bottle rwh?

rwh · Post by **rwh** » Tuesday Aug 21, 2007 3:14 pm

Yep, only while it's still fermenting. Once it's complete, cap it and put it into the fridge. I'd also modify the pitching instructions. I'd first pour off the "beer" from on top of the yeast slurry, leaving only enough to swirl up the yeast slurry, and then pitch that. Either that or make another starter from it.

Stubbie · Post by **Stubbie** » Tuesday Aug 21, 2007 9:22 pm

And I'd be extra careful to santise the tap good and proper, inside and out before drawing your sample.

nt · Post by nt » Wednesday Aug 22, 2007 11:02 am

I like the idea, only I would chill it immediately. They will become a bottle bomb when left unchilled.

Boonie · Post by **Boonie** » Wednesday Aug 22, 2007 12:32 pm

Noodles wrote:This is the easiest method i've seen of making a starter. Can anyone experienced in making starters tell me why I should or shouldn't use the following method?

When your brew us at the height of its fermentation, usually around the three to four day mark, tap off 600-700 ml of the fermenting beer into a sterilized soft drink bottle (plastic) and seal it tight. Allow this to ferment a further 12-24 hours and then put the bottle in your fridge. It is important to make sure that the bottle has plenty of pressure in it when it is placed in the fridge. The cold will put the yeast on hold until you are ready to use it again.
To reactivate the yeast it is simply a matter of taking the bottle out of the fridge one day before you want to brew, giving it a good shake and allowing it to stand in a warm, dark spot. When the contents of the bottle start to ferment it is ready to add to your next brew. This procedure can be repeated two to three times before the yeast may mutate and affect the flavour of the brew.

Like the idea, simple, effective and brilliant.

And I'd be extra careful to santise the tap good and proper, inside and out before drawing your sample.

You could submerse it with a margarine tub or similar.... or if you use the non rinse stuff, just spray on with a Spray Bottle.

Great work fellas....

Cheers

Boonie