Black grapes, also sometimes known as Concord grapes or slip-skin grapes, are sold fresh or made into fresh juice, jams or jellies.

So can guinea pigs eat black grapes at all?

Let’s take a look at their nutritional data and find out more.

In particular, we are interested in their acidic, water, sugar, fat, salt, calcium and phosphorus content as far as guinea pigs are concerned.

Nutritional value per 100 g (3.5 oz)
Energy 288 kJ (69 kcal)
Carbohydrates
18.1 g
Sugars 15.48 g
Dietary fiber 0.9 g
Fat
0.16 g
Protein
0.72 g
Vitamins
Thiamine (B1) (6%) 0.069 mg
Riboflavin (B2) (6%) 0.07 mg
Niacin (B3) (1%) 0.188 mg
Pantothenic acid (B5) (1%) 0.05 mg
Vitamin B6 (7%) 0.086 mg
Folate (B9) (1%) 2 μg
Choline (1%) 5.6 mg
Vitamin C (4%) 3.2 mg
Vit E (1%) 0.19 mg
Vitamin K (14%) 14.6 μg
Minerals
Calcium (1%) 10 mg
Iron (3%) 0.36 mg
Magnesium (2%) 7 mg
Manganese (3%) 0.071 mg
Phosphorus (3%) 20 mg
Potassium (4%) 191 mg
Sodium (0%) 2 mg
Zinc (1%) 0.07 mg
Other constituents
Fluoride 7.8 µg

source wikipedia

As you can see, black grapes contain a hint of salt, calcium and fat, a little phosphorus, quite a bit of acidic content, and a lot of sugar.

This means that black grapes are ok to eat one or two at a time every so often.

But because of their high sugar content, don’t give too much to piggies as too many will harm them.

Make sure they don’t have any stones in them, as they may get lodged in a guinea pig’s thoat.