# Maybe underpitched lager?



## tubbsy (13/4/21)

I brewed a version of a Munich Dunkel on Sunday in my new BIAB setup (65L digiboil) and am pressure fermenting in a 50L keg. All went great with the wort going into the fermenter at 17C and me realising I have double the wort so I pitched 2 packets of Lallemand Diamond yeast. Not sure how it's supposed to be, but the pressure was at 12.5psi after 36 hours and I plan on holding it at 14psi. The keg isn't currently temp controlled, but the weather has been chilly so the room has been sitting around 9-12C.

Only today did I notice that the pitching rate is 1-2g/L and I only pitched 22g for the 42L wort. Is it too late to pitch some more yeast, or should I just let it run it's course? I don't have any more Diamond yeast, but do have 1 each of WLP802 and WLP820.


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## MHB (13/4/21)

When you pitch, the yeast starts to reproduce, during reproduction it uses up either Oxygen in the wort or Glycogens it has stored in the cell. It also consumes Amino acids and lipids (fats) and lots of other bits and pieces.

When it runs out of any of the vital nutrients it stops reproducing and starts making alcohol.
If you add more yeast it won’t have all the bits that the earlier yeast has already consumed so it wont reproduce much.
A teaspoon of dry yeast becomes cups full of yeast during the start of fermentation literally hundreds or thousands of times as much as you started with, so later addition aren’t really going to help, yeast needs to go in at the start.

In part this is why we have recommended pitching rates and defined Oxygen levels. If you make a good quality wort, oxygenate properly and pitch the right amount of yeast. It will eat all the undesirable proteins and lipids as well as growing to a suitable population to give a quick clean ferment. Without leaving staling products (lipids) undesirable proteins or making stressed yeast flavours.
Smart money is to use the right pitch rate for the style, gravity, temperature...
Mark


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## Hangover68 (13/4/21)

I also unkowingly under pitched a dunkel, i ended up brewing a woolies lager and dry hopped with the same hops then blended the 2 before bottling. 
Came out quite drinkable and better then going down the drain.


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