OG correction for pitching onto yeast cake

[pdog44450]

I brewed a est. 1.090 Imperial Stout. Because of my BIAB kettle size limitations, I was forced to mash at a super thick 1.05qt/lb. Obviously I did not get good sugar extraction so I was expecting my OG to be a little low, but I measured a 1.078. One of the reasons I think I was so low is because I pitched onto a large yeast cake from my previous batch. My question is how much do you think a yeast cake would dilute the OG reading and if you had to guess what my actual OG is given I took the reading after I mixed the cake and wort?

 

[pdog44450]

I brewed a est. 1.090 Imperial Stout. Because of my BIAB kettle size limitations, I was forced to mash at a super thick 1.05qt/lb. Obviously I did not get good sugar extraction so I was expecting my OG to be a little low, but I measured a 1.078. One of the reasons I think I was so low is because I pitched onto a large yeast cake from my previous batch. My question is how much do you think a yeast cake/trub would dilute the OG reading?

 

[Yooper]

my question is how much do you think a yeast cake/trub would dilute the og reading?

0.

 

[JimRausch]

None. A hydrometer measures dissolved solids. Trub and yeast are all non-dissolved
For the future, one of the best things you can do is measure your SG toward the end of the boil and keep some DME on hand. 1 lb. of DME in a 5G batch will add about another 8 points, and would have gotten you just about where you wanted to be.

 

[DurtyChemist]

I wouldn't expect a yeast cake to lower the sugar concentration until about a day after. If you measured the gravity right after adding the wort from your brew kettle you just had bad extraction from the bigger grain bill. It happens.

 

[dsaavedra]

If there was leftover beer mixed in with the yeast cake it would dilute the gravity a little bit. But unless you left like a half gallon of beer on the yeast cake or something I can't imagine it would have that much of a noticeable impact.

 

[pdog44450]

I wouldn't expect a yeast cake to lower the sugar concentration until about a day after. If you measured the gravity right after adding the wort from your brew kettle you just had bad extraction from the bigger grain bill. It happens.

Yeah I really wanted to brew this so I just tried it expecting bad extraction. 11.5lbs in a 4 gallon kettle BIAB is not advised in case you were wondering

 

[pdog44450]

None. A hydrometer measures dissolved solids. Trub and yeast are all non-dissolved
For the future, one of the best things you can do is measure your SG toward the end of the boil and keep some DME on hand. 1 lb. of DME in a 5G batch will add about another 8 points, and would have gotten you just about where you wanted to be.

I've never used DME to raise OG, does this add body and flavor or just for bumping ABV a little?

 

[pdog44450]

If there was leftover beer mixed in with the yeast cake it would dilute the gravity a little bit. But unless you left like a half gallon of beer on the yeast cake or something I can't imagine it would have that much of a noticeable impact.

It was a pretty huge cake. There was not much beer from what I could tell, I racked as much as I possibly could and even racked a little of the cake as to not overpitch. It was definitely mostly yeast and trub rather than beer

 

[flars]

I've never used DME to raise OG, does this add body and flavor or just for bumping ABV a little?

DME can add flavor depending upon which one you use. There is extra light and Pilsen light, about 2°L, to extra dark and special dark, 90°L, depending on the manufacturer naming.

DME will not add to body because it is 1000% fermentable.