Lager yeast starter and fermenting temperature questions (Oktoberfest)

Hello all, I have a couple questions regarding doing an Oktoberfest.

Allright, so I already did a pretty simple batch of Oktoberfest. This was the first yeast starter I made, so I hope I did it right. I didn't have a stir plate or flask, so I just did it in a growler and shook it whenever I could. The OG was pretty close at 1.052, but the FG was way too high at 1.018. Also, they aren't carbonated very well. I used Wyeast #2633 Octoberfest Lager Blend, details found here. It says an optimum temp of 48-58 F, so I put it in the fridge at ~53 with some fluctuation for 2 weeks, then lagered at around 40F for 2 months.

Ok, so I'm looking to redo it. This time, I got a flask and stir plate, so I'm going to use those. According to Mr. Malty calculations, I need about 1.5L of starter and use 2 starter packets, so I'm going to do that. I'm going to use 6 cups of water and 1.5 cups of DME.

1. Does it matter what DME I use for the starter? Most places I've seen just say to use light DME, but Oktoberfest is darker, so should I use darker DME?
2. Should the starter be stirring at room temp (around 69F) or should it be chilled to the optimum range it is indicated at?
3. Last time I tried putting it in the fridge overnight to decant, but the yeast didn't settle out very well and I ended up just pitching all of it. Is this hard to do with lager yeast or should I just pitch all of the starter?

I'm also still not sure about the fermentation schedule for lagers. I went straight from 2 weeks at ~53F to 2 months at ~40F, without really letting any time for it to cool down. Some sources recommend letting it sit at RT for a day or two, but when exactly? Between primary and lagering? After lagering but before bottling? After brewing but before Primary? Should I let it sit at RT at all?

Also, I was asked from a friend if I was going to replenish some yeast before bottling, and I didn't, but the beer did come out pretty flat. It's not terrible, but definitely not carbonated enough. Should I save some of the yeast from the starter to pitch then, or will it not make a difference?

Sorry for the long post, any input is appreciated.

 

For the starter, you only need to build up the yeast, it doesn't matter what the medium does. I pour out the wort and only leave enough to loosen up the yeast cake that forms at the bottom.

I do mine at room temps, then bring it down to pitching temp of around 54. The yeast should just settle as it grows.

My lager went from 54 to 60, back to 54, then down to mid thirties as the outside temps allowed. I have since built my lagerator, 2 garbage cans with a layer of insulation between them. That keeps the temps steady even as it gets warm in NYC in February.

 

1. I think you will be okay with the darker DME. I've done the same in the past for a Schwarzbier.

2. Your yeast will reproduce faster at room temperature. If I have a lot of time I do my lager starters at fermentation temperatures, but usually it's just room temperature. On the other hand, I usually decant and pitch because I am doing very large starters. I think you will be okay with your plan.

3. Your volume is pretty small so just pitch the whole starter at high krausen (12-18 hours after you pitch your liquid yeast into your starter). A Friday night starter for a Saturday afternoon/evening pitch usually works just fine.

4. Here's a foolproof lager fermentation schedule for you:

(a) cool your wort to 65 degrees, pitch your active starter, aerate as well as you can (pure O2 if possible).

(b) place your fermenter in the fridge set at 53 and let the wort cool down to that temperature over the next several hours.

(c) when you are about 8 points above target FG (if you are not sure what this is, do a forced fermentation test), start your diacetyl rest by removing your fermenter from the fridge and leaving at room temperature. For your Oktoberfest I would suggest doing this at 1.020 or just above, although some people will wait just a bit longer. I like to do this when fermentation is still active. If you are too lazy to take a gravity reading, watch for the krausen to fall and wait another day or so.

(d) leave your beer at room temperature for at least a couple of days (I do a week or more), then rack it to a secondary for lagering.

(e) cool your beer to lagering temperature, which is as cold as you can get it above freezing. Some people like to cool their beer slowly (3-5 degrees per day) and others cold crash it. I tend to cold crash it since my fermentation schedule is long enough that I have always hit FG before I start lagering (not everyone does).

(f) lager 1 week per 8 gravity points. Not everyone has the patience to do that.

(g) you should not have to add yeast before bottling but it doesn't hurt and could save you the heartache of an undercarbonated batch. 1/3 of a pack of a clean strain of dry ale yeast (i.e. US-05) rehydrated in your bottling bucket will be plenty, then 3 weeks at 70 degrees. Or use a lager yeast like S-23 and bottle conditionsaround 60 degrees.

 

Thanks for the advice, osagedr.

 

You are welcome; good luck!

 

Starters are made for growth, so no matter if you are looking to ferment an ale or a lager, you should grow at room temperatures, or even warmer. Just for reference sake, Saccharomyces in the lab is grown near 80F (Saccharomyces for research purposes is actually grown at 86F).

Everything else is preference, but if I were trying to make the best beer possible, I would make the starter well in advance so you have plenty of time to crash the starter, so you can decant the spent wort. I wouldn't want oxidized, phenolic wort being poured into a delicate lager.

Also, I believe that if you pitch on the cooler side (say, 46-48F) then ramp up to your fermentation temperature, you'll find there's no need for a diacetyl rest. Of course, the given method is to simply taste the wort when fermentation appears to be slowing. Your palate is your ultimate guide. Regardless, in some cases, you may want to slowly ramp up your temperature anyway, to ensure complete fermentation.

Once you hit terminal gravity, then proceed to lager.

 

I generally pitch cool myself; then again I'd want 425 billion cells for a 5.5 gallon batch of 1.055 Oktoberfest. But with new lager brewers, underpitching is the biggest mistake. Couple that with low temperatures and you have yet another thread about why did my lager get stuck. Thus the advice to pitch warm-ish and give the yeast a chance.

 

Some good info in this thread. Posting to make future searches for it easier. Thanks.

 

Ditto

 

+1

 

When you say crash the starter, does that mean to put it in the fridge overnight or a few days, or like a freezer? Because I put mine in a fridge overnight, and when I tried to decant by pouring the yeast was still in suspension pretty well. I ended up pitching the whole thing (although it was a pretty small starter, which was a mistake on my part).

Terminal gravity, I love that.

 

Yeah, fridge for a couple days. Some yeasts are definitely more resilient to compacting to others. I get in binds sometimes, too...had to pitch all my 1007 two weeks ago because it wasn't settling worth a damn.

 

Chilling and decanting is always my preference. But I don't mind pitching a few litres of starter into a 21 litre batch. Most brewers seem comfortable with the practice; moreover they don't plan far enough ahead to ferment the starter out before pitching or find it inconvenient to do so.

 

+1

 

+1