Cooling Lager Prior to Yeast Pitch

Hi all,

I'm getting ready to brew my first lager (which will also be my first all grain batch. This is probably a very bad idea...). I was reading John Palmer's book, where in the latest edition he recommends cooling the wort to fermentation temperature prior to pitching the yeast (rather than pitching at 70 and then cooling to optimum fermentation temp). This makes good sense to me. But since I'll be working with White Labs #833, this means going all the way down to 48-55 degrees F.

My question is -- how am I supposed to do this?? I've got a two-stage immersion chiller that will get the wort down to 70 pretty quick, but no way it'll get it to 50. Should I stick the immersion-cooled wort in the carboy, put it in the fridge, and let it sit overnight to get down to 50, prior to pitching the yeast? It makes me a little nervous to leave vulnerable wort exposed for so long, but I don't see any real alternative.

-Matt

Yes I would wait to pitch my yeast. If you need to put it in the fridge than do it.
My water is cold this time of the year and I get to 55f with an immersion chiller if I leave it going and stirring for 1/2 an hour. I then put it in my fridge until I get 50f and pitch a 45f yeast slurry ( from a starter or yeast cake ) into it. I get a great start and ferment.

As long as everything is sanitary, you should have no worries.

Wow, I too am brewing my first lager tomorrow and was going to post the exact same question. This board rocks!

Although there's no universal agreement, you can do it either way.

1) pitch at fermentation temps and expect a long lag time unless you have a BIG starter. Slight risk of contamination.

2) pitch at room temp and cool when fermentation starts. This is faster but risks (I've never tasted this) some fruity off flavours.

I have made lagers for 4 years during the winter months where my garage get down to the nice temperature of about 55 F for fermentations. I boil my worts and cool to about 75 F with an emersion chiller. I then pitch my lager yeast at 75 F and place it in my 55 F garage. In some cases, I have placed my primary fermenter in the house overnight to allow the yeast to get a good start before cooling to the 55 F. In all cases, I have not had any major flavor effects (fruity, sulfury) from this practice. In fact, I have had excellent lagers. I feel the warmer temperatures for the first 12 - 24 hours allows the yeast to get going. I also use a yeast starter.

Dr Malt

If you pitch between 60-70 and immediately put it in your cooler environment, it will likely cool to optimum ferment temps before the yeast really start working anyway. Of course, there will be people who want to split hairs and argue that even an hour at higher than recommended temps will utterly ruin your batch even during lag time, but unless someone blind taste tests it, I'm undecided.

Though pitching lagers cold is the preferred way, you shouldn't do this unless you have the proper amount of yeast to pitch (about 100ml (3oz) of yeast sediment for an average 5 gal batch) and the ability to bring the wort to that temp before pitching w/o having to wait long. pitching warm and letting it coold during then initial hours would be safer.

I bring the wort below 50F by using a utility pump in a bucket with ice water to circulate this ice water though the immersion chiller after I got the wort below 70 with tap water. This idea comes from Jamil (see mrmalty.com). He also has a good pitching calculator on this page.

Kai

do what kaiser suggested regarding the ice water in your chiller. Then pitch big.

This will keep away the diacetyl which means you won't need to bring the beer up to 70 after primary for a diacetyl rest. It will also help you limit esters which are more appropriate to ales than lagers.

Dantodd:

I am not sure I am clear on your thinking on the diacetyl and not needing a diacetyl rest. Could you give me a brief reasoning on what you are referring to?

Thanks.

Dr Malt

Diacetyl precursors are created in much greater abundance at high temperatures. Usually when you pitch at 70 and then drop of the 40s for fermentation there are enough diacetyl precursors to exceed the taste threshold for the average drinker. Bringing the beer up to 70 again about 3/4 of the way through fermentation will induce the yeast to consume the diacetyl precursors. If you pitch at fermentation temperatures there are many fewer precursors produced and even if they are converted to diacetyl it will be at below the taste threshold.

Jamil Z. in a podcast I listened to recently said he doesn't do a diacetyl rest and pitches at fermentation temperatures. I jsut listened to John Palmer on Basic Brewing and he pitches at fermentation temperatures and still does a diacetyl rest.

Doing a diacetyl rest usually depends on the strain of yeast used such as WY2308 but don't hurt to do for any lager since most of the fermentation is done by the time you bring up the temps to do the rest.

I think pitching an good starter at slightly below fermenting temps into wort at fermenting temps reduces the esters and fusels you'll get by pitching into warmer than recommended lager fermenting temperture wort.

I tried a recipie I brewed a while back using higher fermenting temps and got a good beer, but not a crisp lager.

Thanks Dantodd for the explanation. If you would like a little more information on diacetyl, you might go to http://brewingtechniques.com/library/backissue1.2/fix.html.

The temperature will have an effect on the rate of metabolism of the yeast and thus the rate of diacetyl formation, but fermenting at cooler temperatures will not inhibit the formation of diacetyl. Lager yeast will still make plenty of diacetyl at their optimum fermentation temperatures (50 -55 F). So, even if you start your fermentation at say 50 F, the fermenting beer will have high diacetyl levels during primary fermentation. Once the yeast have utilized most of the mono, di, and triose sugars, they will begin metabolizing the diacetyl and thus reducing the levels. Breweries do a diacetyl rest (warm the fermentation for a short time) to speed the assimilation of the diacetyl by the yeast so they can package and sell the beer sooner. If you are not in a hurry, you can let the beer sit at fermentation temperatures (50 -55 F) longer and the yeast will continue to lower the diacetyl levels below flavor threshold. Because diacetyl will be made in abundance anyway during primary fermentation, I am not convinced DiegoPro needs to go to great lengths to cool his wort to 55 F initially because of diacetyl. If he gets it to say 70 F, pitches his yeast and then places it at 55 F, he should not have a problem with diacetyl if he either ferments for sufficinet time or does a diacetyl rest.

Thanks.

Dr Malt

Dr Malt said:

Thanks Dantodd for the explanation. If you would like a little more information on diacetyl, you might go to http://brewingtechniques.com/library/backissue1.2/fix.html.

Click to expand...

Thanks for the info! The link you supplied, though, seems broke. I found the article on my own though (you were missing an 's' in 'backissues'). Thanks for the reference. Here it is for everyone else:

http://www.brewingtechniques.com/library/backissues/issue1.2/fix.html