Trimming and Cubing

This is the least glamorous hour in sausage making and the one that most determines how the day goes. Everything after it is machinery and schedules. This part is a knife, a cutting board, and a series of small judgments about what belongs in the sausage and what doesn’t.

I want to make a case for taking it seriously, because the temptation — especially on a big batch — is to hurry through it. Hurrying here shows up three steps later as a grinder that keeps jamming, a bind that never quite arrives, and a cut face full of chewy white threads that nobody wants to eat.

What you are actually deciding

Three things, in this order:

What comes out — sinew, silverskin, gristle, glands, bruised meat, bone chips.
What the lean-to-fat ratio is going to be — because you are building to a target, not trusting a cut.
How big the pieces are — sized to your grinder throat, and consistent.

The first is about eating quality. The second is about whether the sausage works at all. The third is about whether your afternoon is pleasant.

Sinew, silverskin, and what “trimmed” actually means

Silverskin is the tough, pearlescent connective-tissue sheath that lies on the surface of muscles. It is collagen, and the important fact about it is that it does not grind — it wraps. A grinder plate cannot cut it cleanly, so it gets caught on the knife, spun around the auger, and progressively wound into a fibrous plug that blocks the plate holes. That is the real cause of “my grinder stopped extruding and just squeezed out gray mush”: the plate is blocked by a wad of connective tissue and the meat is being pushed through the few remaining holes under pressure, heating up as it goes.

So: silverskin off. Slide a thin flexible knife under one edge, angle the blade slightly upward toward the skin, and pull the sheet off in strips. You lose a little meat. Lose it.

Sinew and heavy gristle — the white cords, the joint capsule material, anything that feels like a rubber band — comes out too, for the same mechanical reason and for eating quality. Nobody chews their way through a chewy thread in a bratwurst and thinks well of the sausage.

But not all connective tissue is the enemy, and this is where the popular advice oversimplifies. Fine intramuscular collagen is supposed to be in there. Some traditional sausages depend on it: the German food code specifies sinew-rich beef (sehnenreiches Rindfleisch) for Landjäger, and cotechino and zampone are built substantially on rind and collagen-rich cuts, because that collagen turns to gelatin and gives the sausage its particular unctuous body.

The distinction I use: if you can see it as a discrete white sheet or cord, take it out. If it is dispersed through the muscle, leave it. A pork shoulder trimmed to look like a loin has been ruined for sausage.

Glands, bruises, and the things nobody mentions

Lymph nodes are the ones to actually know about. In pork shoulder and jowl especially there are small, firm, grayish-tan nodules embedded in the fat — usually pea to marble sized, sometimes larger. They are not dangerous in any acute sense, but they taste bitter and metallic and one of them will make itself known across an entire batch. Cut them out. They feel distinctly different from fat under a knife: dense and rubbery where the fat is yielding.

Bruised meat — dark, blood-shot areas — comes out. It carries a strong off-flavor that concentrates when cured.

Bone chips. If you are working from a bone-in cut, run your fingers over every surface after boning. A bone chip will chip a grinder knife and destroy a plate, and it is the one contaminant a customer or a family member will actually bite.

Skin/rind: off, unless you are deliberately making a collagen-rich sausage that calls for it. Rind is not grindable by a home machine in any useful way.

Building to a fat target instead of trusting a cut

This is the part I would most like to convince you of, because it changes results immediately.

Recipes say “5 lb pork shoulder.” Pork shoulder is not a fixed thing. A Boston butt from a lean commercial hog might come in around 80/20 lean to fat; one from a heritage pig raised outdoors might be 65/35 or fattier. If your recipe assumed one and you bought the other, you are 15 percentage points off on the single most important ratio in the sausage, and no amount of care later fixes it.

So separate as you trim. I cube into two bins: lean and fat. Anything obviously in between — a piece with a good marbled proportion — I judge and assign. Then I weigh the two piles and build the block to the ratio I actually want.

The targets I work to, and why:

Sausage	Fat %	Why that number
Fresh sausage (brat, Italian, breakfast)	25–30%	Below ~20% it eats dry and the texture goes crumbly. Above ~35% it renders out and shrinks.
Emulsified (frank, bologna)	25–30%	The emulsion needs the fat; the protein and water hold it.
Dry-cured (salami, Landjäger)	25–30%	Fat doesn’t dry, so a very fat salami never loses its weight; a very lean one goes to leather.
Lean cured (some summer sausages)	20–25%	Tolerable because the cook step and the binder carry it.
Wild game	30–40% added pork fat	Deer and elk bring essentially no usable fat of their own.

The classic shorthand is 70/30, and it is a good default that will make a decent sausage out of almost anything. But it is a default, not a law, and knowing why you’d deviate is the point. The full argument is on fat.

Wild game deserves its own line. Deer fat tastes waxy and turns rancid fast — trim it off and throw it away, don’t try to be thrifty. The fat in a venison sausage should be pork. I run 60/40 venison to fatty pork for most things, which lands the finished block somewhere near 70/30 overall depending on how fat the pork is.

How big to cube

Two constraints: your grinder’s throat, and consistency.

Size to the throat. For my Weston #12 that means pieces roughly 1 to 1½ inches — small enough to drop in without forcing, large enough that I’m not cutting all afternoon. Pieces that need to be pushed with the stomper under real pressure are pieces that are too big, and forcing meat is how you heat it.

Consistency matters more than size. A bin of evenly-sized cubes feeds at an even rate, which means an even grind and even temperature. A bin with a few big chunks in it will jam, and the jam is where the heat comes from.

Cut strips, then cubes. Slabs into strips the width you want, strips across into cubes. It is faster and far more even than hacking at a mass.

Keep lean and fat separate right through to the grinder if you can. Some formulas call for grinding them separately at different plate sizes — coarse fat with finer lean, or vice versa — and you cannot do that if you’ve already mixed the bins.

Trim while it’s cold — but not frozen

A cold piece of meat cuts cleanly; a room-temperature one drags and tears, and the silverskin is much harder to get under. But frozen meat can’t be trimmed at all.

The working order that solves this: trim first, at refrigerator temperature, then cube, then freeze. Trimming is the slow step, and doing it at 38°F is fine because none of that meat is ground yet — the fat is still in intact tissue and it isn’t going to smear sitting on a board. Once it is cubed, it goes onto sheet pans and into the freezer to hit the 30°F working temperature before it ever sees the grinder.

Do not trim on a warm day next to a sunny window with the meat sitting out for an hour. The chain starts here.

Knives

Nothing exotic. A 6-inch flexible boning knife does 90% of the work — the flex is what lets you follow a bone and slide under silverskin. A stiff 8- or 10-inch chef’s or cimeter for cubing, because you want to cut straight down through a slab without sawing.

Sharpen more often than you think. A dull knife tears the silverskin instead of slipping under it, and tearing means you leave half of it behind and take twice as much meat with the half you get. I hone every few minutes of trimming. It is the single cheapest improvement to this step.

Yield, and being honest about it

You will lose weight in trimming, and knowing roughly how much lets you buy correctly.

From a bone-in pork shoulder I expect to lose something like 20–25% to bone, skin, silverskin and glands. From a boneless butt, more like 5–10%. From a whole venison hindquarter, a lot — deer carry silverskin heavily and it all has to go.

So when a recipe says 5 lb of meat, that is 5 lb of trimmed, cubed meat going into the block, not 5 lb walking out of the store. This trips people up constantly and produces batches that are short and over-seasoned, because the salt and cure were calculated on a weight the block never actually reached.

Weigh the trimmed block. Every percentage in this craft — salt at 2.5%, cure at 0.25%, fat at 30% — is a percentage of the meat block, and the meat block is what is in front of you after trimming, not what was on the receipt.

What I do with the trim

Not much of it is waste.

Clean fat that didn’t make the ratio goes into a bag in the freezer and becomes rendered lard or gets added to a leaner batch later.
Silverskin, sinew and bone go into a stockpot. Connective tissue is gelatin waiting to happen, and a sausage-trim stock is genuinely good.
Glands, bruised meat, anything off goes in the bin. Do not be thrifty with the bitter parts.

Part of Making Sausage. Next: grinding — plate sizes, single versus double grind, and the chart off my own machine.