Lab-Grade Maltose Monohydrate, 100g - The Curated Chemical Collection

I bought this product to use in growth media for bacteria. It worked perfectly fine. The E. coli grew great. And I really appreciated not having to buy through Sigma Aldrich. The price was great.

The experiment I'm doing requires a solution of pure maltose with little or no glucose. The material I received looks and smells exactly like ordinary brewer's dry malt extract (which contains tons of glucose!). If I wanted DME, I would have bought an ordinary homebrew product for 12x lower price. Labeling this product simply "maltose" is false advertising - basically akin to marketing a can of beer as "water." Boo, ALDON, boo, Amazon.

According to Sigma, d-maltose monohydrate should be clear, colorless in a 1 M H2O solution, and is easily soluble in water. The bottle I received had no safety seal, and contained a light yellow-colored material with a strong odor, which was poorly soluble in water, similar to starch. 9 grams in a 100 ml solution turned the water dark brown and extremely turbid, like wastewater. I would check the optical rotation, if only light transmitted through it... I have no idea what this is, but I'm returning it.

I suspect that this is from a source of un-purified malt, since yeast growth is better in this product than with other sources of lab-grade maltose monohydrate. Do not purchase if you need a purified source of maltose.

Very good material with excellent purity. The grain sizes were consistent and there were no foreign materials in this maltose.

Exactly what it said it was!

Fast shipping, accurate description

Very good for laboratory tests!