Home Forums Hunting & Shooting Hunter's Campfire Math Problem, meat to fat ratio?

I used to know this and do this, but for the life of me I can’t figure it out.

If I have x number of pounds of Beef Trim @50/50, how much lean100% is added to get 80/20 ?

1 pound of 100% plus 1 pound of 50/50 will give you 2 pounds.

That two pounds will contain 1.5 pounds of 100% and 0.5 pounds of fat... that is 75/25 mix

If you do 10 pounds of 100% plus 3 pound of 50/50 you will have 13 pounds... that is 82/18 or something like that.

Maybe I am wrong... complex math has always been hard for me... when I butcher deer I just use a boatload of bacon or pork butt and don't care.

1.5x additional

If you have 20 LB of 50/50 you have 10 LB of lean and 10 LB of fat.

Mathwise: 0.5 * 20 = 10. 0.5 being 50% for you boomers.

To get a mix that is only 20% fat the total mass would need to be brought to 50 LB.

Mathwise: 10 LB fat already there / 0.2 = 50. Again for boomers 0.2 being 20% and / being the symbol for division.

In case there is a window licker out there: 50 LB target - 20 LB already gathered up = add 30 LB lean. 40 LB Lean / 10 LB fat = 80 / 20.

One more way to look at it:

you have beef to fat 1:1. You want 80:20 which is 4 to 1. . Adding 3x the amount of meat to what you already have comes up to (3 + 1):1 or 4:1.

So, just weigh your 1:1 mix to find out how much meat is in it. If you have 6lb total, you have 3 lb of meat in it. Add 3x that meat (9lb) to the original 3 lb and it gives you 12 lb of meat : 3 lb of fat. 4:1.

Thanks guys.

I went through my sausage notes and found this.
Does this sound correct.

Meat to fat 80/20

X/lbs of fat = 80/20

16lbs @60/40 for example

16 x .4 = 6.4 lbs fat
16 x .6 = 9.6 l s Lean meat

X/6.4 = 80/20

Cross multiply = 25.6

Subtract existing meat 9.6 = 16 pounds of lean added.

Sound right?

Last time I added fat to deer

The sack of beef trimmings I got from “Bo and Bob’s “

One big chunk of fat had ADIDAS pressed into it
Also, was a wad of hair, looked like Ginger from Gilligans Island cleaned her hair brush out

no more after that.

Just started buying boston butt pork and bacon ends to grind in.


Man I tell ya...I’ve seen some sheeyott....where the fugg my PTSD check?????

Never had anything like that from my suppliers.

My last 60 pound box of Pork Special trim was marked 70/30, it was perfect. Out of 60 pounds I only tossed 3/4 pound of schit and I’m pretty picky about what goes into my sausage.

This beef trim is marked 50/50,(20 pound bag) looks about right, after cleaning it up I tossed just under a pound .

20 pounds of 50/50 is 10 pounds fat and 10 pounds lean is it not? You need 40 pounds lean to go with your 10 pounds of fat to get to 80/20 do you not?
If so, I would think 30 more pounds of lean would do it.
Maybe one and a half times lean in weight added to the 50/50 would work every time. 75 pounds lean and 50 pounds of 50/50 would be the same ratio I think. That would make 125 pounds 25 of which is fat, hence 80/20. If you are working with smaller amounts you could move the decimal over and do 7.5 pounds to 5 pounds.
I'm not real good at figuring in my head, so put this on paper and check it out.

I do the math differently because I always start with the weight of lean meat I have on hand.

If I have 10 lbs of meat (80%) that I want to mix with 20% fat:

10 lbs x 100 / 80 = 12.5 lbs total mix

Once more: if I have 42.3 lbs of lean meat that I want to mix 75/25:

42.3 lbs x 100 / 75 = 56.4 lbs total mix.

Make the subtraction to determine how much fat is needed (14.1 lbs).

My son just told me to KISS.

Multiply the weight in fat by 4, subtract the existing weight of lean.

I never understood algebra but I think simple arithmetic will work but we must remember the fat addition to the lean is 50% lean. Wouldn't my formula which amounts to 1.5 lean to 1 of the 50/50 work? That way if I'm right the resulting 2.5 would be .5 fat. You have to allow for the lean that is in the fat. It works on paper but becomes inexact when you start feeding it through the grinder.

That works fine. It's the same as what I said about 3x the meat except its based on the total wt, not the lean meat part. 6= 1/2 doz.