Yeast Starter Question

[mosto]

Hi all,

Just after a bit of advice re my yeast starter. I've got a 6 month old Wyeast 2001 smack pack. I smacked it last Friday, and it took a couple of days to swell. On Sunday I boiled up 100g of LDME in 1L of water (I read that this should give a SG of 1040). When it cooled to room temp, I poured it into a clean, sanitised 2L juice bottle along with the 2001. I don't have a stir plate so just sat it on the fridge and gave it a shake when I went passed. I just sat the cap on just loose enough to let CO2 escape, tightening it properly to shake. By Monday night it was letting an almighty hiss out when loosening the cap after shaking. The only thing is it didn't really froth up much on it's own like my only other starter, which was re-cultured Coopers yeast. I'm assuming maybe because this is a lager strain?

Anyway, it's not letting a hiss out at all now and the frothing is dying off after I shake much more quickly than a day or so ago. I was a little worried that it hadn't worked so I took a gravity reading and it was 1016, so the yeast has obviously been active. My plan now is to boil up another litre of wort and step it up to 2L and pitch on the weekend.

So is the lack of visible activity, compared to the Coopers, mainly due to it being a lager strain? Sorry if this seems a bit obvious, but it's only my second starter and I'm still working out what I need to look for.

Also, I've plugged the figures into a couple of calculators, and it seems, even with the starter, I may be under-pitching a bit, but haven't really got the equipment to step it up over 2L. I'm thinking I should have gone maybe 500ml->1L->2L. Does this seem reasonable? Any other advice appreciated.

Cheers,

 

[Brad Churchill]

Don't worry about the fact it didn't form froth (Krausen).
Some strains don't.

The only real problem I can see is if you are under pitching by a long shot (being a lager) you may end up with a beer full of diacetyl. (Buttery flavour and mouthfeel.)

If you are under pitching by only a small amount say 10% probably not such a problem provided you have temperature control and do a diacetyl rest.

If you are not familiar with a diacetyl rest it is where you increase fermentation temp once fermentation is say 3/4 complete and it helps get rid off those buttery flavours that don't go so well with lagers.

Hope this helps somewhat.

I don't make many lagers but yeah you need a lot more yeast cells than with ales because of the cooler fermenting temps and you really want temp control.

You probably realise this but did you select lager when you were using the calculators?

Cheers
Brad

 

[mosto]

Cheers Brad, thanks for the tips. Will do a d-rest to minimise the diacetyl. I use a fridge and STC1000 so temp control is not a problem. I'm estimating an OG 1045 and FG 1011 so will up temp once it hits around 1020. Had the calculators set for lager, and thoguht I may be under-pitching, but was surprised by how much!

 

[mikec]

You probably don't need to shake the bottle.
Just give it a good swirl every time you walk past, leaving the lid as it is so CO2 can escape as you do it.

 

[warra48]

Personally, iI believe a 1 litre starter from a 6 months old pack of Wyeast 2001 will certainly be underpitching for a lager, particularly if you control the fermentation temperature.
Heck, it's even underpitching with a 1 litre starter from a fresh pack.

There's nothing to stop you building up your starter again. Just add another 3 or so litres of 1.040 wort, aerate, and go through the same procedure as before.
You'll be closer to what you need.

 

[mosto]

Thanks all for the advice. Yeah, while I knew the cell count refor a lager was larger due to the lower ferment temp, I was surprised how much larger. With the couple of lagers I've done so far I've just pitched a couple of packets of S23 withput really thining about it (with pretty good results including a 2nd at the nationals), but want to move into the world of liquid yeasts, particularly with this as it's my first crack at a proper Pilsner.

I don't really have a vessel that I can go more than 2L in, so I'll add another litre of wort and have to go with that, even though it's under pitching. I work in IT repair, so it looks like the DIY computer fan stir plate will be the next project and a 5L flask the next purchase :icon_cheers:

 

[CosmicBertie]

Thanks all for the advice. Yeah, while I knew the cell count refor a lager was larger due to the lower ferment temp, I was surprised how much larger. With the couple of lagers I've done so far I've just pitched a couple of packets of S23 withput really thining about it (with pretty good results including a 2nd at the nationals), but want to move into the world of liquid yeasts, particularly with this as it's my first crack at a proper Pilsner.

I don't really have a vessel that I can go more than 2L in, so I'll add another litre of wort and have to go with that, even though it's under pitching. I work in IT repair, so it looks like the DIY computer fan stir plate will be the next project and a 5L flask the next purchase :icon_cheers:

Ferment the starter out. Put the vessel in the fridge and allow it to drop clear, this can take a few days. Then boil up another 2L of wort and cool that. Take vessel out of fridge, tip off the 'beer' (and have a taste to make it doesnt taste like crap), then pour the 2L of cool wort in your vessel. Then let it ferment out again.

You should see I distinct build up of yeast at the bottom of the vessel once its cleared out.

 

[mosto]

Ferment the starter out. Put the vessel in the fridge and allow it to drop clear, this can take a few days. Then boil up another 2L of wort and cool that. Take vessel out of fridge, tip off the 'beer' (and have a taste to make it doesnt taste like crap), then pour the 2L of cool wort in your vessel. Then let it ferment out again.

You should see I distinct build up of yeast at the bottom of the vessel once its cleared out.

Cheers for the tip CB, will do.

 

[stux]

Thanks all for the advice. Yeah, while I knew the cell count refor a lager was larger due to the lower ferment temp, I was surprised how much larger. With the couple of lagers I've done so far I've just pitched a couple of packets of S23 withput really thining about it (with pretty good results including a 2nd at the nationals), but want to move into the world of liquid yeasts, particularly with this as it's my first crack at a proper Pilsner.

I don't really have a vessel that I can go more than 2L in, so I'll add another litre of wort and have to go with that, even though it's under pitching. I work in IT repair, so it looks like the DIY computer fan stir plate will be the next project and a 5L flask the next purchase :icon_cheers:

Good purchases

I would recommend a 1L and 2L as well

Great for stepping up splits and older yeasts. I use my 500ml flask for only the oldest most unviable splits.

Generally I use about 50-75% of the capacity of flask.

So might have 500ml in the 1L, will then transfer that to 1L in the 2L to get 1.5L. Then transfer that to 2L in the 5L for 3.5L.

Then might chill, decant the spent wort and add up to another 4L to get the big pitches

All on a stirplate

 

[squirt in the turns]

Ferment the starter out. Put the vessel in the fridge and allow it to drop clear, this can take a few days. Then boil up another 2L of wort and cool that. Take vessel out of fridge, tip off the 'beer' (and have a taste to make it doesnt taste like crap), then pour the 2L of cool wort in your vessel. Then let it ferment out again.

You should see I distinct build up of yeast at the bottom of the vessel once its cleared out.

This will work, but repeatedly chilling the yeast to get it to drop out of suspension, then letting it warm up again, is not very good for it, assuming you'll chill and decant again after the 2nd 2 litre stage. Mainly I think you'll affect the viability, probably not to a great extent, but it's less than ideal (well, a lot of the processes we adopt as homebrewers are less than ideal, but you see what I mean).

Obviously, aerating the starter wort and letting the temperature rise above normal fermentation levels is conducive to growing yeast, but you'll want to get rid of the oxidised, estery "beer" that you'll produce in the process, so at least one chill-and-decant step is probably always going to be necessary.

I don't really have a vessel that I can go more than 2L in, so I'll add another litre of wort and have to go with that, even though it's under pitching. I work in IT repair, so it looks like the DIY computer fan stir plate will be the next project and a 5L flask the next purchase :icon_cheers:

Another option to consider: before I got a 5 L flask, I used to make lager starters in a 2 L flask (utilising a stir plate once I'd made one), then pitch that into 5 L of wort in the fermenter itself. If you wish to chill and decant again after this step, it's quite easy to pour off the beer through the fermenter tap without disturbing too much yeast.

If you can be bothered, that 5 L of wort can be a mini version of your main batch, or at least hopped to be compatible with it. Or you can up your main batch IBUs to account for the 5 L of unhopped wort. Ferment that 5 L at appropriate lager temps and avoid aerating it too much after the initial pitch, and you can then pitch your main batch directly into it at high krausen, which is traditionally considered the optimal time to pitch.

This doesn't apply to you, mosto, but if you're an AG (or full-volume-boil extract) brewer who no-chills, then it's ridiculously easy to reserve 5 L of wort that is identical to your main batch, for this purpose.