Determining Fat Content of Arbitrary Meat with a Microwave

[SmokinEdge]

On the contrary. My knowledge is quite satisfactory to me without having to express it in raw numbers to everyone else.

I have a number of recipes I have done so many times that I know, by eye, or feel, how much of this or that to add. May not be a useful method to share the recipe with others, but it's quite sufficient and satisfactory for my own uses.

This is called “experience “ which is exactly what I originally posted. Without the experience it can be different.

 

[DougE]

I don't think I have any recipes I'd be unwilling to share, but some of them I "just do" and have no raw numbers.

 

[SmokinEdge]

I don't think I have any recipes I'd be unwilling to share, but some of them I "just do" and have no raw numbers.

Of those recipes, how many are variable on success? You , I assume, use eyeball, and feel for final mix? How is this possible for success?

 

[DougE]

Of those recipes, how many are variable on success? You , I assume, use eyeball, and feel for final mix? How is this possible for success?

Most have some amount of wiggle room as far as spices, but salt and cure, if applicable are pretty much set, but the rest is open to personal taste.

 

[geostriata]

On the contrary. My knowledge is quite satisfactory to me without having to express it in raw numbers to everyone else.

Lord Kelvin was a bit of a zealot in that regard! He's saying that he (as a scientist) finds a certain sort of knowledge meager and unsatisfactory. As a scientist, he's obsessed with reproducibility and sharing knowledge with the world, and without being able to quantify his findings, he finds that very incomplete and problematic.

The quote was meant to show the value in that sort of scientific rigor, because that value was currently being questioned. It was not to imply something as absurd as "you can't cook if you don't quantify absolutely everything with numbers." Rather, I was saying "this method of quantifying things can be useful."

Imagine a rule on this forum that you can only express recipes with tablespoons & teaspoons. Wouldn't that be frustrating? Wouldn't you yearn for something more precise, especially when talking about cure #1 amounts? That's the sort of frustration that Kelvin is getting at.

So I created a thread that I felt was useful to capture fat percentage. There was pushback on this, as if somehow having awareness of fat percentage is somehow a bad thing. That's the part I disagree with.

 

[SmokinEdge]

Lord Kelvin was a bit of a zealot in that regard! He's saying that he (as a scientist) finds a certain sort of knowledge meager and unsatisfactory. As a scientist, he's obsessed with reproducibility and sharing knowledge with the world, and without being able to quantify his findings, he finds that very incomplete and problematic.

The quote was meant to show the value in that sort of scientific rigor, because that value was being questioned. It was not to imply something as absurd as "you can't cook if you don't have numbers."

I really do appreciate what you are trying to do and the text of your original post. Nothing wrong with being technical. And by the way, much of what we do in sausage must be technical and fairly precise like salt and curing salt. But otherwise, as you go along the rest is sometimes feel, or look. As in fat or added water. In small batches I often just eyeball it all, except for salt and cure 1, but the rest is from experience. If doing large batches the measuring of everything on the metric scale is a must. My point in all of this is don’t take it all too seriously. Relax and have fun with it. There are parameters and limits to be followed but consider this. Some of the best sausage recipes we have came from places like Italy or Poland. From 1000’s of years ago. Did they build those recipes with gram scales? Or did they simply use experience? Enjoy the ride, and keep making sausage.

 

[geostriata]

But otherwise, as you go along the rest is sometimes feel, or look. As in fat or added water. In small batches I often just eyeball it all, except for salt and cure 1, but the rest is from experience.

I understand, and it's great that that approach works well for you. Most everything can be cooked well that way. Brilliant Chef's can work through feel and their intuition and create wonderful masterpieces without looking at a book or anything. That sort of beauty and experience is valuable and should not be discounted.

If that chef saw a studious kid with his nose in a book instead of smelling the spices or watching the technique, then I'd definitely agree that the kid's "sweating the small (or scientific) stuff" is a distraction from what matters.

However, that's not what is happening here. I've been working on a creation, and I'm trying to make my batches consistent. Like really really consistent. I want to make it 10 times and for all 10 batches to be exactly the same. What I'm finding is that, when it comes to consistency, eyeballing it simply doesn't work.

My point in all of this is don’t take it all too seriously. Relax and have fun with it.

That's exactly what I'm doing! I certainly wouldn't be spending all this time on it if I didn't find it fun. This is my passion, and going to extreme lengths to make my beef sticks 0.01% better is super fun for me. To me, experimenting and digging into the science of meat to find out why my batches aren't very consistent is an awesome way to spend a Friday night. Yes, I recognize that what is fun for me is very weird :)

 

[SmokinEdge]

I understand, and it's great that that approach works well for you. Most everything can be cooked well that way. Brilliant Chef's can work through feel and their intuition and create wonderful masterpieces without looking at a book or anything. That sort of beauty and experience is valuable and should not be discounted.

If that chef saw a studious kid with his nose in a book instead of smelling the spices or watching the technique, then I'd definitely agree that the kid's "sweating the small (or scientific) stuff" is a distraction from what matters.

However, that's not what is happening here. I've been working on a creation, and I'm trying to make my batches consistent. Like really really consistent. I want to make it 10 times and for all 10 batches to be exactly the same. What I'm finding is that, when it comes to consistency, eyeballing it simply doesn't work.



That's exactly what I'm doing! I certainly wouldn't be spending all this time on it if I didn't find it fun. This is my passion, and going to extreme lengths to make my beef sticks 0.01% better is super fun for me. To me, experimenting and digging into the science of meat to find out why my batches aren't very consistent is an awesome way to spend a Friday night. Yes, I recognize that what is fun for me is very weird :)

Best of luck.

 

[Hijack73]

I have a question. Back at the beginning of this, I saw you post that you want your sticks really really dry. What if what you want isn't necessarily what the sticks need to be to satisfy your wants? I am guessing you've gone down the rabbit hole on moisture content prior to fat content, but sometimes I guess wrong.

If you can't find a magic number on fat content, I would think that the only other variable would be moisture - or possibly but less likely, the protein extraction itself.

 

[geostriata]

I have a question. Back at the beginning of this, I saw you post that you want your sticks really really dry. What if what you want isn't necessarily what the sticks need to be to satisfy your wants? I am guessing you've gone down the rabbit hole on moisture content prior to fat content, but sometimes I guess wrong.

If you can't find a magic number on fat content, I would think that the only other variable would be moisture - or possibly but less likely, the protein extraction itself.

Moisture content correlates with fat content. Fat holds on to less moisture than lean, and knowing this, we can deduce the fat % by computing the amount of moisture in the product. This is the approach used by Univ. Pennsylvania and my initial post.

As for what I want. I suppose I should really say I want "much drier than most" or "shelf stable dry" to be the most clear. Every single non-fermented snack stick recipe/guide I've ever seen on the internet yields a product that is not shelf stable. Too much moisture or water activity in the product, which will cause it to spoil over time. More importantly, I like the taste better when it tastes more like dried meat and less like a floppy slim jim.

Fortunately, I've found what I want. Around batch 47-50, I got to a result that is both shelf-stable and delicious. So to answer your question, what I want is a delicious tasting beef stick, and I'm able to create what I want most of the time. The issue is consistency. Every now and then, I'd end up with a batch that was not quite as good -- why is that? Was the fat too high? Was it too low? Was it because it was a bigger batch? Was it the conditions of the smoker? Protein extraction? Etc... These are questions that I ask myself to try to figure out what has gone awry. Fortunately, a bit of science usually leads me to the answer.

For example, in batch #59, I found the end result to not look so good. Normally my snack sticks wrinkle after 27 hours, but these didn't appear wrinkly as I would have expected. Something was wrong. They were are about 49% weight loss after 27 hours of smoking, which is close to target. This leads me to think they aren't too fatty (because it'd take longer to hit 49% loss if they were too fatty) and that they aren't too lean either (because it'd be around 53% weight @ 27hrs if it were). But then again, maybe changes in the weather could cause smoker conditions to be somewhat variable. What if my heat was not as stable? This is where the fat% calculation can be helpful to know.

Fortunately, in batch #59, I had my fat% calculation performed, which gave me the evidence I needed to know that it wasn't my meat mix that was to blame. It turns out that batch #59 was simply the largest batch I had attempted so far, and as a result, the meat mixing process was to blame as I figured it out on my new mixer. So you called it actually: protein extraction :)

 

[kingpapawawa]

There was a sale on untrimmed tri-tip ($5/lb) recently, so I tried to make snack sticks out of it. Despite it having a lot of extra fat, the end result was not good. There wasn't enough fat. As someone who's made a ton of sausages at this point, it was a bit disappointing that I still couldn't eyeball the ground meat for fat content. Determined to avoid this problem again, I set out to find a way to empirically determine the fat content of ground meat. At a minimum, this will be a useful sanity check when I'm trying new meat sources.

So I found this resource from the University of Pennsylvania and tried it out. With a little tweaking and extra derivations, I think I've got it dialed in for an easy check during sausage making. I'll share those results here.

Here's a summary of the approach:
1. Find out how long it takes your warmed microwave to evaporate all moisture from 20g of meat.
2. Prepare your sample meat by processing it into a pink blob (ensuring uniformity of fat and lean).
3. Tare a beaker (or pyrex container) on the scale. Weight out 20g of the pink meat into a beaker. Store the exact weight (e.g., 20.12g)
4. Cover with a napkin/paper towel and rubber band and weight that. (e.g., 23g)
5. Warm your microwave by nuking 250-500g of salt for 4 mins
6. Nuke the sample for your calibrated time in step #1.
7. Weight the result (e.g., 10g).
8. Using the weights from #3, #4, and #7 you can compute fat percentage.

Let's do it! First I started with store-bought ground beef.

View attachment 701580

They claimed it was 27% fat. Let's find out if that's true or not!

View attachment 701581

I then took a good amount and put it in the food processor. Since I'll be using some for calibration, I wanted a little extra.

View attachment 701582

This resulted in a pink blob, which was needed for a uniform sample of lean and fat.

View attachment 701583
I tared the empty beaker on the scale, and weighed out 20.39g of the pink meat.

View attachment 701584

I then put a rubber band and napkin on the top. As you're nuking the product, it'll splatter. We want that oil splatter to be shown in the final result, so we can't have it splattering outside the beaker.

The above process is the same for when we're doing an actual sample. For now, we're using this bit of meat to calibrate our Microwave. So I set the beaker aside for a moment...

View attachment 701586

I then filled a container with 250g of salt and put that in the center of the Microwave. I then turned the Microwave on full for 5 minutes. This warms up the Microwave and ensures a repeatable environment for the evaporation step.

Then I put the sample in the Microwave, along with the warm salt, and Microwaved it at intervals of 30 seconds and weighed the results very quickly, trying to minimize the time outside of the microwave:

Initial Weight	WeightwNapkin	1min	2min	2:30	3:00
20.06g	22.41	12.89	10.7	10.6	10.51

As you can see, it only lost less than a percent in the final 30 seconds (and it started to smell) and an exact 1% at 2:30. So I decided to call my Microwave calibration figure 2 minutes. Now since this taking it in and out of the microwave disrupts the measurements, I then ran two trials with new samples. (Two trials are good, because it's easy to have outlier results periodically with this approach).

W_initial (Initial Weight)	W_napkin (Weight w/ Napkin and band)	W_final (2min final weight)
20.23g	23.09g	11.03g
20.33g	23.26g	11.07g

Since the results are within 1% of each other, I know they are good. So I proceeded to find the moisture% of the sample. The formula for this is:

((W_initial - W_final - (W_napkin - W_initial)) / W-initial)*100 = %Moisture
So,
((20.23 - 11.03 - (23.09-20.23)) / (20.23))*100 = 59.96%
​

Now that we have the moisture content, we can determine the fat percentage, which is as follows:

100 - ((%Moisture * 1.27) + 1.1) = %fat
So,
100 - ((59.96 * 1.27) + 1.1) = 24.8% fat
​

So despite them advertising 27% fat, this sample is actually 24.8% fat.

Let's try another example!
View attachment 701588

Here we have my typical brisket point/flat combination. I find this usually gives a solid fat percentage. Just looking at the ground meat, what would you estimate the fat percentage to be?

I ran through the test and got the following.

W_initial	W_napkin	W_final (2min)	%Moisture	%Fat
20.16	22.99	11.22	58.38	24.75
20.55	23.45	10.84	61.36	21
20.28	23.07	11.32	57.94	25.31

As you can see, the middle trial was a bit of an outlier. It was more than 1% different with the first trial, so I ran a third trial and got better measurements (I think there was some oil splatter uncaught with the second trial, which affected the results). So I averaged trial #1 and #2 to determine that the brisket cuts were 25% fat.


Let's do another example for the Tri-Tip. The meat that didn't yield a good outcome for me.

View attachment 701589

Look at all that fat! I think it's misleading...

View attachment 701590

I ground the lean bits separately more coarse (because I like how the 'show meat' improves texture), but don't worry, we can still determine the fat content. We just need more samples. But first, consider asking yourself: What do you think the fat percentage of these two mixed together is?

I ran through the tests for both types of meat.

Type	W_initial	W_napkin	W_final (2min)	%Moisture	%Fat
Lean Tri-Tip #1	20.39	22.96	8.30	71.9	7.59
Lean Tri-Tip #2	20.06	22.06	7.78	71.19	8.49
Fatty Tri-Tip #1	20.18	23.00	11.92	54.9	29.17
Fatty Tri-Tip #2	20.29	23.22	12.08	54.9	29.17

So you can see the lean was, as expected, low fat (avg 8% fat). And the fattier bits were much higher fat (29.17% fat).

Now I can determine the mixed fat content by simply weighing all the lean ground, weighing all the fatty ground. I had 992.9g of the lean and 2101.8g of the fatty ground. So:

((W_lean * %fat_lean) + (W_fatty * %fat_fatty)) / (W_lean + W_fatty) = Fat%combined
So,
((992.9 * 0.08) + (2101.8 * 0.2917)) / (2108.8 + 992.9) = 22.3%
​

The tri-tip was 22.3% fat! This explains why my last batch of beef sticks were not good! In addition, I think the last tritip I used was a bit leaner, so I may have been making beef sticks at 20% fat or so. So nice to have a scientific explanation of this!

So, to make a batch out of this tri-tip, I simply dropped the amount of lean I used by half to get to my minimum fat content for beef sticks.

((W_lean * %fat_lean) + (W_fatty * %fat_fatty)) / (W_lean + W_fatty) = Fat%combined
So,
((496.45 * 0.08) + (2101.8 * 0.2917)) / (2108.8 + 496.45) = 25%​

Hope that helps! Even if you don't run this computation for yourself, it's good to see a variety of ground meat and their fat contents. Personally, I plan to run this test as a quick sanity check whenever I'm doing a batch. There are benefits to reliably having the same fat percentage between batches...

i dont know if i can math that much. it is easier for me to separate and weigh my fat and lean. but it was a great read and experiment and i appreciate the effort.

 

[geostriata]

i dont know if i can math that much. it is easier for me to separate and weigh my fat and lean. but it was a great read and experiment and i appreciate the effort.

Yeah. It's a bit of math, and I think if you have a good eye and don't care as much about consistency between batches, it's not needed. But it's a useful tool to have, if you're troubleshooting or trying to get really consistent. In any case, once you get a sense of how moisture relates to fat content, it's really all about:

(Weight_Initial - Weight_dry) / Weight_Initial = Moisture%
​

Which is another way of saying that the amount of Moisture% in the meat is proportional to your max weight loss. In other words, using weight loss to see when things are done is ideal. So I'll just keep doing that, but also take a couple mins to do the above check when I want to (e.g., such as using new meats).

In addition, I find separating meat from fat takes so long for some cuts of meat. Moreover, I just find that my meat doesn't separate all that well from the fat. For example, tri-tip lean is interleaved with fat and still 8% fat. So even if you separated it out and called it 0% fat, then your mix would still be fattier than you expect. That's why I wanted to learn how to do the above -- help train my eye with cuts of meat for consistency.

That being said, I'm certainly not saying artisan sausage makers need to do this or even should do this. It's just a useful tool to have if one wants to use it, and in can help in some situations or depending on your goals.

 

[DougE]

Trying to distill the art of sausage making down into raw number is not something the masters who came before us ever did. Some of the process just requires experience that can't be broken down into raw numbers.

 

[geostriata]

Trying to distill the art of sausage making down into raw number is not something the masters who came before us ever did. Some of the process just requires experience that can't be broken down into raw numbers.

First off, that's not what I'm trying to do. I am trying to present tool to use and inform and assist in sausage making, roughly equivalent to computing weight loss to see if your fermented sticks are shelf stable, for example. This in no way distills sausage making into a raw number. That would be silly.

Secondly, just because something wasn't done in the past doesn't mean we can't do it in the future. That is exactly why master commercial sausage makers employ this technique in the present day. There are even really expensive automated devices to perform this test. I'm simply trying to show a cool trick to enable the home sausage-makers to have a form of the same tool that commercial makers have. This should not be controversial.

 

[Dave in AZ]

I guarantee that Hormel, Swift, Oscar Mayer, Pepperidge Farm etc are ALL running fat content tests for every batch, just like this. And I guarantee that if the guy in charge made a batch WITHOUT running fat content tests, and recording 50 datapoints needed for USDA FSIS proof of process, he would be fired. Touting experience and past masters is all well and good, but the ACTUAL masters who produce to a high quality standard, who are held to a process standard, who enforce extreme safety standards and repeatable taste/texture, are all data-driven. Down-talking data sampling and use, and calling that somehow better, is just false. Anyone who is forced to make a profit and ensure customer expectations are met, batch after batch, while keeping sufficient proof of correct procedures for inspections, uses data.

I don't really understand where this push back is coming from... do what you want for your own stuff, eyeball everything if you want, but to criticize someone else for actually doing a few tests for repeatability? Seems really odd to me...

I'm quite interested to see how my eyeball estimates of fat content compare to reality! I bet I'm off by 4%, one way or the other! Seems like a fun project.