OG too low - what's up?

[ssashton]

Today I brewed a new to me recipe - Brewboard/WHC/TMM Colab – Majorvane – NEIPA

The grain bill is:

1710g Simpsons Finest Pale Ale Golden Promise
1040g Crisp CaraGold Malt
460g Crisp Dextrin Malt
750g Crisp Naked Oat Malt
760g Crisp Torrified Wheat

4720g total

The recipe says OG should be 1059 but I only got 1030! I'd appreciate some thoughts on what might have happened.

There is 500g of milk lactose to add in total and 200g already added. I don't think 300g milk lactose will add more than a few points.

Today I simultaneously brewed another beer and got OG 1061 so I don't think with a target of 1063 so I don't think my method is too far wrong.

My thought is that a lot of this grain bill might not have much enzymes for converting starch to sugar so relies on the diastatic power of the base malt which is not a lot. However I don't really know the diastatic power of each of those malts. Also one would imagine that being a collaboration recipe between well known names (I assume!) they will have brewed this more than once and measured the OG, not just calculated it. Thoughts?

Should I do a small brew with some more base malt and add it to the fermenter tomorrow?

 

[The Baron]

I think you are on the right track apart from the golden promise I think all the rest have virtually no Diastatic power and it look like a low conversion.
I am not a full blown expert who goes into it too technically but it looks that way to me

 

[Sandimas]

I just plugged the figures into Brewers Friend and got OG 1056, assuming a 75% efficiency. Must admit that I was quite surprised that it was this high due to such a small percentage of base malt, but I've never brewed a NEIPA and those other malt seem to be contributing more than expected.

So the recipe looks sound, which then comes down to your technique. What AG method are you using, how many times have you brewed with this AG method, what is you usual brewhouse efficiency? I played about in BF and to get the target OG 1059 you need 79% efficiency, which is rather high e.g. I only get 68% with BIAB.

All AG recipes are only an approximation as our individual efficiencies are different due to equipment and technique. You need to take the recipe and adjust for your efficiency, adding more grain or taking some away to hit the target OG. As this recipe had a rather high efficiency I'd suggest you needed more grain as yours will probably be lower. In fact, I again played with BF and you only got 40% efficiency as you ended up with OG 1030. So a very inefficient mash.

Here's the link to BF if you want to play, I find it invaluable for learning about brewing, different grains etc. https://www.brewersfriend.com/homebrew/recipe/calculator

 

[chopps]

Brewfather shows 1.044 OG using their defaults for Grainfather G30 and 75% mash efficiency.

What equipment and batch size are you using?

 

[The Baron]

To get such a low Efficiency you must have done something/missed something in your process as that is very low.
You could do a small batch with base malt to add to the wort to lift the gravity as you suggested but we need to try and find out why so low?

 

[ssashton]

Thanks for the replies!

Does the mash need to be done differently if using the diastolic power of a base malt with lots of adjunct?

The only thing I can think of is maybe the mash got too hot on the bottom of the kettle where the heater is. Though the recipe says mash 66c and I only saw it peak as high as 70c.

I think I might have had a bad OG reading. The Kveik yeast was prepped for 12 hours in wort at 28c. I pitched it in the beer last night at 10pm left at room temp. I checked gravity again now at 4pm. I got a reading of 1032.

Somehow I've gained 2pt gravity (at least not lost any) even though it has done 18 hours of fermentation.

How much you think had already been eaten by the yeast in the first 18 hours? It already has krausen.

I think what happened is that I added 5L water to the wort to being it from 15L that I boil to 20L. However I didnt stir it, I just waited 5 min to sanitize a ladle and then took a sample from the top. Guess maybe water was sitting on the top of the wort??