This method is quick, simple and accurate. It utilizes a trout egg measuring trough that is easily made but also available from many aquaculture suppliers.

The trough measures 30.5cm (12″) length (inside dimension), with a 45º bend and a depth of approximately 3.5cm (1.4″).

There are two steps in using the Von Bayer method

• First sizing the eggs
• Then counting the eggs

Sizing the eggs:

1. 1. Eggs during transit can become dehydrated and slightly smaller in size, so it is important to rehydrate the eggs in flowing water.
   2. Fill your Von Bayer trough with a single row of eggs.
   3. Use a non-sharp pointed object (pencil) to discard extra eggs from the trough. Do not force the eggs into the trough. The eggs should fit side-by-side, just touching, but there should not be any spaces.
   4. Count the number of eggs that fill the trough.
   5. Repeat this process 3-5 times to ensure an accurate count.
   6. Refer to the Von Bayer chart below to determine the size of the eggs (#eggs per liter or per liquid ounce).

1. Take a 1 litre (or 1 quart if using fluid ounces.) plastic measuring cup or jug. If necessary, cut off any portion of the cup that is over the 1 litre or 1 quart mark. This will make it faster and easier to level the measured eggs.
2. Fill the measuring cup at least half full of water.
3. Use a strainer (plastic rice colander works well) and add eggs to the cup. Tap the side of the cup to get rid of air bubbles and to settle the eggs. The eggs will displace the water in the cup.
4. Level eggs at the top of the cup by gently scraping off excess eggs.
5. Pour measured eggs into separate container.
6. Repeat until all eggs have been measured / counted.
7. Multiply number of litres (or quarts) by the number of eggs per litre (or quart) as per the Von Bayer chart. This will give you the total number of eggs.