Lagers- Revising My Process

[brewNYC]

Tried my first lager last week. I am finding that my usual "process" which is based around brewing ales, needs to be updated for lagers. I would like to see how my methodology compares to other lager brewers and open it up to critique.

My usual ale process is:

1. Remove my smack pack from the fridge 96hrs in advance. Pitch a starter 72 hrs in advance, step up 48 hrs in advance and cold crash the night before brewing.

2. Decant starter and place in fermentation chamber on the morning of brew day to warm up to pitching temperature.

3. Do a 20 minute "mash" with specialty grains, then a 60 min boil with extract. I usually save at least some of the extract or sugar until the last 15 min of the boil.

4. Cool my brew kettle in an ice bath, then mix with cold, sterile water (usually 50/50) to obtain my desired O.G.

5. Leave the wort in my fermentation chamber until I reach the lower limit of the yeast's tempurature range. Shake, inject o2 (only if my wort is over 1.06 OG) and pitch yeast.

6. Keep temp low for about 3-5 days, slowly raise to higher limit over 3 days once fermentation starts to slow down. I typically am at FG in one week.

7. Leave in primary or transfer to secondary, depending on style, abv, my mood, or whatever....


So, this didn't work so well for my lager. The yeast pack arrived 72 hrs before brew day hot and swelled up. I pitched it straight into a starter at room temperature. The starter did nothing for 48 hrs, but I "stepped up" anyway. Finally saw some action in the starter the night before brew day. I tried to cold crash the starter, but the yeast stayed in suspension, so I probably threw half of them out when I tried to decant. I wound up pitching the yeast into a 60 degree wort, because it was taking forever to chill down to 48 degrees.

All in all, it wasn't a disaster. I am starting to see some krausen and bubbles after 72 hrs. With that said, I think I will do some things differently next time to avoid under-pitching, pitching into 60 degree wort, and a 72 hour lag time. Here are my ideas:

1. Get my starter going 5 days in advance. Just make a big starter instead of stepping up, and cold crash 2 days before brew day.

2. Brew earlier in the day to give my wort more time to cool.

3. Add o2 to every batch, even if the OG is low. Maybe add another round of o2 after 12 hrs.

4. Leave at lower temp limit for one week, the slowly raise to upper limit for 1 week. Do a diacytl rest for 3 days at 68 degrees after fermentation is over.

5. Transfer to several small secondary containers and lager for 8 weeks in my kitchen fridge (so I can keep other things brewing in my fermentation chamber).

Any other ideas you guys have from your experience with lagers? Any improvements you would make to the process above?

Thanks!

 

[tgolanos]

I do a lot of lagers, so I'll take a stab at this for you. Point-by-point:

1. Remove my smack pack from the fridge 96hrs in advance. Pitch a starter 72 hrs in advance, step up 48 hrs in advance and cold crash the night before brewing.

For lagers, you want a much larger starter than you would do for an ale. Generally, double the size is what is recommended. I tend to do my starters in 2 or 3 steps, ending up with about 4L. You're going to want to give yourself enough time to prepare this.

If you reuse yeast, you might only have to do one step, depending on how much saved yeast you use and/or how healthy the yeast is. There are tons of calculators online to help you with this.

2. Decant starter and place in fermentation chamber on the morning of brew day to warm up to pitching temperature.

This seems OK, but let the starter COOL to fermentation temperature. Keep the yeast temp and the fermentation temp as close as possible. See my answer to point 5 for more info on my usual process.

3. Do a 20 minute "mash" with specialty grains, then a 60 min boil with extract. I usually save at least some of the extract or sugar until the last 15 min of the boil.

4. Cool my brew kettle in an ice bath, then mix with cold, sterile water (usually 50/50) to obtain my desired O.G.

This is good. The brew process is the same for a lager as it would be for an ale.

5. Leave the wort in my fermentation chamber until I reach the lower limit of the yeast's tempurature range. Shake, inject o2 (only if my wort is over 1.06 OG) and pitch yeast.

Lager yeasts love cooler temperatures, so what I normally do is wait until my wort is less than 18°C (cooler is better in my opinion), then I pitch my yeast. This allows warmth for the yeast to begin fermenting beforeany off-flavors can take hold. I then shake the holy hell out of it to oxygenate properly and then allow the wort to cool to fermentation temp. I ferment my lagers at 10°C.

Always oxygenate your wort before fermentation. The yeast need the oxygen to propagate properly. If they don't, you're risking off-flavors from yeast stress.

6. Keep temp low for about 3-5 days, slowly raise to higher limit over 3 days once fermentation starts to slow down. I typically am at FG in one week.

7. Leave in primary or transfer to secondary, depending on style, abv, my mood, or whatever....

Keep your fermentation temp steady until you're at about 75% of your predicted FG. How long this takes varies, but I can usually get there in about 7-10 days in the dead of winter, 4-5 days in summer. Take gravity readings with a hydrometer for exact gravity measurements.

Once you're 75% of the way there, ramp up your lager's temp a few degrees. This is your diacytel rest; this gives your yeast a chance to clean up any by-products it produced and helps to finish up fermentation. Once you're at FG, do as you please. I tend to move my lagers to secondary to free up a fermenter, but it is not 100% necessary. You could bottle-lager, as well.

Patience and meticulousness are the keys with lagers, more so than with ales, I find. Hell, I just bottled a lager that has been sitting cold for 6 months.

If you want a quicker lager, look up the "Quick lager method". I've never used it, but some people swear by it.

Good luck.

 

[dmtaylor]

I think you are on the right track. My only comment has to do with the following:

4. Leave at lower temp limit for one week, the slowly raise to upper limit for 1 week. Do a diacytl rest for 3 days at 68 degrees after fermentation is over.

Lager yeast isn't as slow as you think it is. A diacetyl rest is often unnecessary as well. If you need to do a diacetyl rest, you want to start it when specific gravity is half of what you started with (e.g., if OG=1.060, then begin the d rest when SG=1.030). Waiting until the beer is all finished fermenting will take a much longer time of 3-4 weeks for the diacetyl to clear, if it does at all. On the other hand, if part way through fermentation, you do not smell or taste any diacetyl in a sample, then you can also safely skip the d rest. But on the other other hand, it also doesn't hurt anything to just do a "d rest" and raise temperature during the second half of fermentation anyway. The bulk of the character of the beer happens during about the first 3 days of active fermentation. After that, it is not a bad idea to bring up to 65-68 F or whatever for a warm rest.

Bottom line: Let the yeast work on their own schedule. Don't tell them how many days it will take to do what. It will probably happen quicker than you think. It's always safe to raise temperature way up and keep it there when the specific gravity is about half of what you started with. In my experience, this happens probably about Day 3 after fermentation begins, but that's only a rough guideline, and assumes a good healthy pitch (which it appears you will have covered). But you'll need to sample to know for sure.

Cheers and enjoy.

 

[brewNYC]

Thanks, everyone.

Any comments on the idea of lagering in my kitchen fridge? another thread advised against this, but I don't know why..

Any advantage to adding o2 after 12 hours, or would I just be wasting oxygen on wort that is already saturated?

Thanks!

 

[dmtaylor]

I lager in my fridge. It works great.

Don't add any more oxygen after you pitch. That could be very bad. Just once and you're done. Or even zero. Yeast is tougher than we give them credit for.

 

[madscientist451]

Start saving your yeast and its easier to get a nice healthy amount to pitch.
You don't need oxygen if you have a healthy and the right amount of yeast.
Don't plan your temperature changes in the fermentation chamber based on time, (like a week) pull a sample and see what % attenuation you have, once its past 50% you can crank up the temp.

 

[brewNYC]

Thanks, all good point about going on hydrometer readings. My readings so far indicate this lager ferments at about 1/3 the speed of my typical ale, it will be interesting to see if this is consistent with other lager yeast strains. I'll let everyone know how it goes!

 

[applescrap]

Option b is to come to the dark side and ferment them warm and drink them 10 days later. Ymmv.

 

[SanPancho]

take your sterile water and freeze it. you'll get alot more cooling power out of it frozen than liquid.

 

[brewNYC]

Start saving your yeast and its easier to get a nice healthy amount to pitch.
You don't need oxygen if you have a healthy and the right amount of yeast.
Don't plan your temperature changes in the fermentation chamber based on time, (like a week) pull a sample and see what % attenuation you have, once its past 50% you can crank up the temp.

madscientist - if I "crank up the temp once it's past 50%, will I not have excessive fusel alcohol from fermenting 10 degrees above the yeast temp range for the last 50% of the fermentation?

 

[McKnuckle]

It's best not to "crank" up the temp, but rather to raise it gradually over a few days to, say, 60 or so. That late in primary it will not suffer from fusels, esters, etc. as it would during the first 3 days. The moderately higher temp will shorten the time to reach FG and will accelerate a diacetyl rest, all while preserving the clean fermentation qualities that are key to lager styles.