Tallow 3

In which I overcook the tallow

Another trip back to the market, and the butcher generously provided me with 2.1kg of assorted fat. I added the 600g of tallow from Tallow 2 as a heating medium rather than water, and simmered. This produced approximately 1.5kg of tallow total.

Darker tallow

Unlike Tallow 1, I let the rendering continue at a higher temperature well into the browning stage, so the resultant tallow was significantly darker than my previous efforts.

This could be for several reasons:

• Some fraction of the fat might have reached its smoke point and decomposed, leaving carbon with sufficiently fine grain to pass through the filters.
• Some substance from the meat or connective tissue might have dissolved into the fat, giving it a darker hue.
• It's possible there's some mineral in the tap water that's promoting darker tallow.

Or any number of other things.

Clarifying the tallow

I remelted the tallow at very very low heat, then let it set. The underside of the tallow contained the majority of the darker mass. I scraped it off, then repeated the process. On this second run there was also a dark mass on the underside. I scraped it off and repeated a third time. On the third run, there was no dark mass to scrape off, nor on the fourth. Apparently the tallow had reached its maximum clarity even though it wasn't white. I had removed a total of 429g of tallow and "dark stuff".

Lower yield

The total yield from the preceding experiment and this one was almost exactly 1kg of tallow. That was less than I had expected.

The tallow, being very very soft, was harder to manipulate and transfer from pot to pot, leaving a fraction of itself behind at each stage. I would hazard a wild guess that 10-15% of the total was lost on the sides of pots and pans or poured out with water.

Future attempts

If I have a large enough batch of fat in the future, I shall try as follows: split it up into four batches, and try low-vs-high temperature, and distilled-vs-tap water.

Tallow 2

In which I make two rookie mistakes thus creating unwanted excitement in my kitchen.

I decided to do another tallow rendering for two reasons: First I wanted to take a try at making hand sanitizer now that I have ethanol available, and second because the soaps went over pretty well with F&F.

What goes in

I went to a large local supermarket, rang the butcher's bell, and I asked if he had done any trimming today. When he said he had, I asked if I could get "a couple pounds" of the trimmings. He was happy to oblige, presumably because it was a slow Saturday morning.

I came home and measured it out: precisely 1400g of trimmings, but as you can see from the picture, a rather a high percentage was meat so I'm not sure what the end yield will be.

Getting started

I put the fat in a stewpot with a liter or two of water and turned the gas jet up to medium-high.

You can render fat with no water. It is definitely more efficient: the water's going to boil away or be discarded eventually, and there's no reason to waste the energy turning a liter of liquid water into water vapor. Likewise, it's slightly safer since it's impossible to have a bubble of water pop up through a layer of rendered fat and spatter it everywhere.

I use water because it lets me work directly with big chunks of fat without having to cut them up or grind them, and without spending a lot of time tending the pot at the beginning to make sure the fat melts without burning. By the time the water's boiled away, there's enough liquid fat in the pot to conduct heat to the rest of the contents. It's fire-and-forget.

The smell of rendering

Every time I've done this, I get the smells of cooking food: sizzling bacon mixed with a little stewbeef. Despite this I have heard, over and over, that the smell of rendering is bad. This is one of those things that "everyone knows", it seems. I do open the window and turn on the fan, but it's to get rid of the steam. So either what "everyone knows" is dead wrong, or I've been extremely lucky with the materials I've had to render.

Can someone else who does this please relate your experience? I'd really like to know where this belief comes from.

Rendering

By the 30 minute mark, the liquid bubbling in the pot is dark, more viscous, and spits if you drip a drop of water into it.

At the 0:45 mark, there is clearly no water left in the bottom of the pot. There is a large amount of liquid fat, with the larger pieces floating in it. I checked to make sure nothing was stuck to the bottom, and that the floating bits still included fat that had not liquified. Then I turned the gas down to just over "low": enough to keep the fat bubbling and continue the process.

At the 1:10 mark, it was done. There were huge clumps of solids still floating, but when I fished a couple out and cut them in half, they were all protein. I took the pot off the stove and turned off the gas jet. Later measurement showed 220g of deep-friend protein. Too bad I don't have a dog.

Tip #1: If you have just strained 220g of protein solids out of a pool of hot oil, when setting them aside, do not set them on a styrofoam butcher's tray. Melted styrofoam is neither an attractive nor pleasantly fragrant addition to your kitchen space. -Ed

The liquid tallow

I poured the whole lot through a spaghetti strainer to remove the chunks and got the (relatively) pure fat into a different pot. I waited until water dripped in did NOT spit, then tossed in enough warm water to form a short layer underneath the tallow. Then I stirred the pot to bring the water into contact with the oil and its contents.

The layer of water gives the carbonized bits and chunks still in the tallow somewhere else to be. Most of them are heavier than water, so they fall out of the tallow and into the water. Likewise curing salts or other material from the meat tend to prefer the water to the fat.

I set it aside and let it cool down on the cooktop, then put it in the fridge.

The initial results

Once the tallow had hardened in the fridge, I weighed it. I had 780g of very soft tallow. I'm not kidding, the results tallied exactly 1kg to the gram. The tallow was so soft because the source had included a lot of soft, low melting point beef fat. It was also somewhat brownish, apparently from stuff that had made it through the strainer or that hadn't left the fat for the water.

A little math, for the sake of science: 1400g in, 1000g out, 400g LOI. I assume it's almost all in water lost as steam, because the amount that could have been lost as fryer smoke would be fractional grams at most.

I elected to try and get it to a pure white before proceeding, so I decided to reboil it and filter it more completely through a finer seive, and then through a paper filter.

Second boil

You know, I knew there was a reason I hadn't used water in the second boil the first time I made tallow. I ended up with a mini-BLEVE that blew the lid off the boiler and covered a substantial fraction of my kitchen counters and floor in a fine coating of liquid tallow. Eeew.

I *do* have a chemical rated fire extinguisher, but happily it was not needed.

Tip #2: If you are going to boil water under oil, do it at a rolling boil, like when you make spaghetti and put a little oil on the top. Or don't boil water under oil at all. Or if you do, be prepared to handle surprises. -Ed

After-incident report

In retrospect, the problem was obvious, and the payoff is some practical experience with some fairly cool physics:

The water is essentially in a sealed container: the bottom and sides are the pot, and the "lid" is a coating of oil. The oil "lid" acts something like a blanket: absorbing some heat while reflecting another fraction back into the water. Since the water is in direct contact with the bottom, which is in direct contact with the flame, the water gets hotter much faster than the oil.

There is also a slight pressure exerted on the water due to the weight of the oil. This means that when a substantial bubble of water vapor finally forms and rises through the oil, the oil is pushed away from the part where the bubble comes through, removing the weight of the oil and suddenly creating an area of low pressure in the water. The lower pressure lowers the boiling point of the water underneath, which causes more of the water to suddenly convert to vapor, causing more holes in the oil, causing lower pressure, and each cycle speeds the next. This is not a true BLEVE, because nothing is exploding, but the forces at work are pretty much the same.

In short, it tends to go from a quiet pot to a fountain of oil blowing the lid off your pot in a very small fraction of a second, probably leading to excitement and cleanup projects you might wish you didn't have.

As always, Caveat Scisor.

Things I learned

1. When doing a purifying boil on tallow, skip the water
2. The screen on a Samsung Galaxy Note 3 is liquid-tallow-proof
3. Even though it wasn't used, I'm really glad I have a good fire extinguisher

Conclusion

After the cleanup, I came to the conclusion that there wasn't enough tallow to continue the experiment, so I disposed of the remainder of the tallow and started again at the top.

If the weather continues bad tomorrow, I'll probably go back to the market and begin Tallow #3.

Tallow 1 (beef fat)

My local market advertises "hand trimmed meat", so I asked the butcher if I could have some of the trimmings. He was happy to oblige, for no charge! I got 40 oz of mixed trimmings.

I estimate the composition at about 40% hard fat, 50% soft fat, 10% connective stuff.

• I chopped it as best I could into cubes between 1cm and 1in in size. The connective tissue I just tossed in straight.
• I added 60oz of water to the fat, and boiled it (low boil) for several hours. Suprisingly, it didn't make much of a change in the fat.
• I set it aside for the evening
• I boiled it more vigorously for 2 hrs in the morning, and it clearly began to separate.
• I kept a little water in the bottom of the pot the whole time, but it boiled away rapidly, so I was replacing it fairly frequently.
• After another 2 hrs, the fats seemed to be mostly dissolved.
• I set it inside a sink with cool water, and once it was cool, I put it in the fridge overnight.
• The next morning I broke the tallow cake and emptied out the water underneath, which was crowded and clouded with various material
• I cleaned the pot, put in some more water, tossed the tallow chunks back in, and repeated
• The tallow came out cleaner the second time, as did the water
• A third pass was yet better

I've become convinced that a little judicious scraping of the water-side of the tallow cake does a lot to improve the purity of the next iteration of the cake.

First rendering

Second rendering

A light scrape after the 3rd render made the 4th one dramatically whiter.

Results
* MATERIALS 40 oz beef trimmings, 2-4 gallons of water.
* PROCESS I did 4 renderings, including the initial one.
* PRODUCT The tallow stayed soft at any temperature above refrigerator temps (40 deg F) which is a bit of a bummer.
* YIELD I ended up with 19.5oz of tallow from my initial 40oz "beef trimmings" sample. Not sure if that's good, bad, or typical.