I am a lab chemist and I am confused by the values listed for some items in the Ingredient Weight Chart on your website. Some of the weights that are listed disagree with standards established by the National Institute of Standards (NIST). For example, the weight listed for 1 cup (8 oz) of water is 227 g. This is the weight of water if it was 8 oz dry weight. However, the NIST defines 1 fluid ounce as 29.57 mL. The density of water is 1 g/mL so 1 fl oz of water is equivalent to 29.57 g of water and 8 fl oz of water is equivalent to 236.6 mL or 237 g. Most measuring cups especially those meant for liquids like Pyrex, will contain 237 g of water at the 8 oz mark.

In the same vein, the weight given for vegetable oil does not seem right. Most vegetable oils have a density of 0.92, so 1 cup (8 fl oz) of oil should weigh 218 g instead of 198 g (236.6 g × 0.92). It seems the 198 g value may be based on the dry weight instead of the fluid ounce.

This may not matter much but the oil weight discrepancy is 10% and the water weight discrepancy is 4%. Are the weights given in the recipes on your website based off these values or on the actual weight used when developing the recipe?

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