I am having problems establishing my mash efficiency. NB instruction sheet calls out an OG of 1.040.
Is that the calculated value based on 100% efficiency?
My actual OG reading after mash out and before boiling was 1.044.
I’m confused.
You are close enough… if it was .01 off… then you’d be looking closer…
These gravity numbers comes from knowing “point per pound of grist”… So how many pounds of grist and how much Hot Liquor were used… It cab get a bit complicated…
Heres my long hand for “close enough” starting gravity… pre-brewed…
I’m brewing today… lets use my grain bill then…
2 lbs rye
3 lbs Vienna
4 lbs Pils
I feel comfortable signing 1.035 points per pound grist… And I have a total of 9 pounds…
So (keep this simple) 9 X 35= 315… With me?
I want 6 gallons IN the fermenter. Take your total 316 divided by 6= 52.5…
I can tell you my set up runs around 80% efficiency…Still here?
So then 52.5 X 8= 420 (see, I leave all those other numbers and points out while doing math)
My gravity today will be 1.042… Easy, eh?
Sneezles61
EDIT: right, its the whole picture… I don’t really bother with just the mash numbers…
When recipes are created you will usually see a percentage of efficiency listed. The OG shown will be related to that percentage but not exactly. So if you know the max PPG of your malt bill you can figure what OG may likely be. In your case you did slightly better.
NB is likely basing their OG on a mash efficiency of 70%.
Are you AG or extract brewer? .004 is certainly nothing to be concerned about and if you do a partial boil and top up or even a sparge, then it’s possible your wort is not mixed well and you’re not getting a completely accurate reading.
I always use this as I’m heating up to boil to check my mash efficiency numbers:
Then I take my OG before I pitch yeast at the end of the day.
As @dannyboy58 said, all NB recipe kits are targeted at 70% efficiency.
Rad
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Extract kits should match the OG the recipe calls for. As an all-grain BIAB brewer I’m often more efficient than recipes are designed for and typically it doesn’t matter much
This was a BITB full boil.
I’m beginning to doubt the accuracy of my notes, as the math is off on this batch.
I’ll do better next time.
While on the topic, what is the OG used for?
I’m thinking it allows a ABV calculation (actual measurement) and for the amount of grain to use to hit an ABV target (calculated).
Sound right?
Thanks for the help with this.
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OG
Original Gravity… That is always a number I need to find after its chilled… before the yeast is pitched…Using a refractometer.
That number… tells me “how did I do” with my whole process to make a fermentable wort…
Sneezles61
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You are correct. OG is the number you use to calculate ABV. There are online calculators you can use. I’m terrible at hand written notes myself so I committed to a program long ago. BeerSmith is my choice. Makes it easy to keep all the info right there in one spot, just plug in your raw data and it does the calculations for you.
Also as a bag brewer you’ll find that even with a full volume mash you’ll likely get a little higher efficiency than expected. I BIAB with more traditional volumes and a sparge. My mash efficiency is close to 100% on beers below 1.080 so I calculate all my recipes on 85% except bigger beers which I do at 80. I just anticipate it and adjust my grist bill slightly. I’m still consistently over what the software predicts but that consistency is the key. I know what to expect and plan accordingly. That’s the only reason efficiency numbers matter. Higher efficiency isn’t some measure of brewing prowess, it’s just a measure of your system’s ability to extract and process sweet wort from grain.
Exactly. Consistency is more important than efficiency. As long as you can hit the same efficiency consistently then you can adjust your recipes. Of course we don’t want to be too low. But on 5-10gal batches your talking a half pound to a pound of grain. Not that big of a deal.
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Most the time i hit 75% mash efficiencies. I do hand calcultion. And check my self. With brewers friend. But on the end. Do think. Og. Gives me the final answer.
