Our Garbage Disposal performance TestRaw Chicken Scraps

Be Nguyen
Be Nguyen
Reviewer
Lap Vo
Lap Vo
Head of RTR
Nguyen Ntk
Nguyen Ntk
Visual Specialist
Updated

Leftover chicken bones are among the most common kitchen scraps, and the toughest, as well. It’s natural to wonder if your existing garbage disposal—or any model, that is—can take care of them. In this test, we’ll be focusing on what an in-sink food disposer system can do with uncooked scraps from defleshed chicken thighs, and how well.

Why Raw Chicken Scraps Matter

Going through the different manuals, we found out that it is actually recommended by garbage disposal manufacturers to grind animal bones as it can help clean the grind chamber. 

The idea is, as the bones are being shredded, the broken-up yet hard bone tissues help scour the details inside the chamber. If you have heard about grinding ice, the two methods basically work on the same premise. 

For this test, we decided to use chicken bones, specifically raw leftovers after deboning the thighs, because of how common they are.

In our Scrap Mix test, we have already included materials from deboned chicken thighs, but they were all cooked. This time around, we go to the other end and let these in-sink grinders try their grind assemblies on uncooked bones, instead.

From the results, we can see that the uncooked bone tissues break up and go through the grind chamber without noticeable hiccups, not unlike what happens to cooked bones; the soft tissues, however, are much more relentless. Raw skin, tendon, and cartilage are fibrous and spongy, so the disposals need significantly more time and water to process them.

Test Procedure

Preparation

In this test, we mainly focus on the time it takes for every product to break down all the non-fibrous tissues from the input load, i.e. the bone and the cartilage. We also assess the materials out the other end, specifically how fine they are.

List of equipment:

  • Rubber cleaning gloves
  • Scale
  • Stopwatch
  • Noise level meter
  • Running water
  • Drain baffle
  • Garbage disposal
  • (Layer 1) Shallow, 18½-inch plastic colander with round holes (~ 0.08 sq in)
  • (Layer 2) Deep, 18½-inch plastic colander with rounded square holes (~ 0.05 sq in)
  • Deep, 20-inch container

The two colanders are stacked upon one another to make a two-layer screener. The shallow colander with larger holes is meant to catch the large pieces of ground materials while the deeper one with narrower holes is for the smaller pieces. Samples on each layer are to be weighed and scored.

List of Ingredients:

Raw Chicken Scraps List of Ingredients
  • Uncooked chicken (thigh) bones:  ~ 7.4 oz (205–215 g) 

*The figures are for one run.

The bones we bought came in packages and varied in sizes and weights, so we had to make adjustments here and there (cutting out extra skin or scraping remaining meat from the bones) to make sure that the input load is approximately the same across the board. 

Since it’s impossible to weigh the exact amount of the skin and the other soft tissues, we increase the number of bone pieces and let those factors balance themselves out. For every run, we aim to test up to 4 sets of bones, with each set (two conjoint pieces)* weighing about 1.85 oz. (50-53 g). In total, each run requires approximately 7.4 oz. (200-210 g).

*We purposely look for sets of thigh bones that aren’t separate to test out the verticality of each disposers.  

Execution

  • Step 1: With the splash guard and the container in position, we put the prepared chicken scraps in the sink.
  • Step 2: We put on running water, turn on the machine, and proceed to flush everything down. We start the stopwatch once the first piece of scraps enter the chamber. A run finishes when most of the tough issues have been processed*.

*When most of the tough tissues have left the grind chamber, the noise level dives down.

We halt the stopwatch if a disposal appears stuck to unjam the motor or if it overheats to wait for the circuit breaker to reset, then continue the test until 3 minutes have passed or a disposal has overheated 3 times. 

  • Step 3: We collect the leftovers (inside the grinding chamber) and the materials on both Layer 1 and Layer 2, then weigh them separately.
Raw Chicken Scraps Step 3

Scoring 

We score each product based on the amount of leftovers, the processing time, and the weights of Layer 1 (large pieces) and Layer 2 (small pieces).

We set the Fail/Pass criteria as follows:

  • If a candidate has overheated three times, the run fails.
  • If the leftovers are more than 20% of input load after 3 minutes, the run fails.

The input load is agreed at 7.4 oz., so if a candidate leaves behind less than 1.48 oz., it will pass.

Time is scored as follows:

  • A candidate scores a 10 if it finishes (less than 1.48 oz. of leftovers) under 2 minutes.
  • For every 15 seconds beyond, a candidate loses 1 point.

We set 2 minutes as the scoring benchmark since even the most capable disposers in our collection take that much time to meet the criteria. 

Next, the leftovers, Layer 1, and Layer 2 are scored:

  • If Leftovers are less than 1% of the input load, a candidate receives 10 points. For every 2% beyond, it loses 1 point.
  • If Layer 1 catches less than 5% of the input load, it receives 10 points. For every 2% beyond, it loses 1 point.
  • If Layer 2 catches less than 10% of the input load, it receives 10 points. For every 3% beyond, it loses 1 point.

To put everything simply, a candidate scores a perfect 10 if, in under 2 minutes, it manages to process 99% of the input load while producing less than 0.37 oz. of large chunks and no more than 0.74 oz. of smaller chunks.

The final rating for the test draws 40% from Leftovers, 20% from Layer 1, 15% from Layer, and 25% from Time.  

Examples

Let’s take a look at some of the results we collected:

  • Insinkerator Evolution Excel: 8.5 points.
Insinkerator Evolution Excel Leftovers
Leftovers weigh 0.19 oz., receiving 9.2 points.
Insinkerator Evolution Excel Layer 1
Layer 1 weighs 0.68 oz., receiving 7.9 points.
Insinkerator Evolution Excel Layer 2
Layer 2 weighs 1.07 oz., receiving 8.5 points.

The final rating of 8.5 draws 3.7 points from Leftovers, 1.6 points from Layer 1, 1.2 points from Layer 2, and 2 points from Time.

  • Moen GX50C: 6.3 points.
Moen GX50C Leftovers
Leftovers weigh 0.6 oz., receiving 6.4 points.
Moen GX50C Layer 1
Layer 1 weighs 0.92 oz., receiving 6.3 points.
Moen GX50C Layer 2
Layer 2 weighs 1.55 oz., receiving 6.4 points.

The final rating of 6.3 draws 2.5 points from Leftovers, 1.3 points from Layer 1, 1 points from Layer 2, and 1.5 points from Time.

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