Does Blackstrap Molasses Contain Harmful Chemicals?

Published Jul 16, 2021

by Nebula Haze

Many cannabis growers use unsulfured blackstrap molasses as a supplement to improve bud quality. Typically they’ll add a small amount to the water they give their plants (for example 1/2 tsp/gallon during last 1-3 weeks before harvest). Some soil growers also give small amounts of molasses to feed the microbes and microorganisms in a living soil or super soil. Marijuana growers have been happily using molasses for decades.

Growers have been giving blackstrap molasses to cannabis plants (as a supplement in the water) for decades

Giving your cannabis plants a little bit of Blackstrap molasses for the last few weeks before harvest may improve both the taste/smell and density of your cannabis buds at harvest

That’s why we were shocked when we received the following email from a reader showing that blackstrap molasses has a cancer warning on it from California! We thought something must be wrong with this particular brand of molasses but we soon learned that nearly all blackstrap molasses has trace amounts of certain chemicals including lead and acrylamide.

Here’s the email we received:

A few days ago I ordered the Golden Barrel Black Strap molasses. The label states that, “consuming this product might expose you to lead and acrylamide.” You don’t want to poison any of your readers do you? Well I might suggest a couple of them. I uploaded a photo of the warning label.


We actually wrote to the manufacturer, and this is what they said:

This subject is confusing and controversial right now. The bottom line is that the state of California has come up with their own list of chemicals and thresholds that they believe could be harmful. Trace amounts of lead is naturally occurring in sugarcane which is concentrated with other minerals in blackstrap molasses. There is no actual evidence that the lead in molasses could lead to any defects but because California has this list and threshold, any item that is being sold in CA containing lead requires this warning. The amount of lead in blackstrap molasses is 0.3 parts per million. To meet Food Chemicals Codex standards, food must contain not more than 10 ppm lead. If blackstrap molasses is found being sold in California without this warning, anyone can bring a lawsuit against the manufacture which has happened to almost every brand and maker of blackstrap molasses. A similar lawsuit is currently ongoing with the coffee industry as they have acrylamide that California says need the same warning. You can Google coffee and Prop 65 for reference. So to sum it up, blackstrap molasses has not changed and we are not adding any lead. It is a very small amount and is naturally occurring. I hope that this makes sense. Let me know if you have any other questions.



  • California requires a warning label on food items that contain lead or acrylamide
  • Molasses naturally contain trace amounts of lead and acrylamide
  • However, there is zero evidence that molasses causes cancer

There is not much evidence molasses can give you cancer, but regulations require that food with any amount of lead or acrylamide must have a warning label.

Alternatives to Molasses

There doesn’t seem to be much (if any) evidence the safety of molasses is worth worrying about. However, if you’re worried, there are a variety of products that have specifically been designed for plants like cannabis that claim to have similar effects including:

Improve Smell

Although I haven’t tried this yet, I’m really intrigued by Botanicare’s Sweet Carbo line. According to Botanicare:

The natural esters in Sweet are easily absorbed by the plant, but are not broken down further once deposited within the plant tissue. This means that as new flowers develop they will contain small amounts of these natural esters which contribute to the overall flavor and aroma of the finished product.

They offer citrusberry, and “raw” (which is just a generally sweet smell). These should be used throughout the flowering stage to help build smell/flavor in the buds as they mature. However, since these contain a small but significant amount of magnesium, they should not be used while flushing during the last 2-3 weeks before harvest. At this point, the smells have already been deposited into the buds. Another cool thing about these supplements is they contain amino acids and some other enhancers, so it’s kind of like getting a lot of different products at once.

The Botanicare Sweet Carbo line offers cannabis supplements to make buds smell like citrusberry, or “raw” (a generally sweet smell)


Bloom Enhancers

The jury is still out and which is the most effective supplement, but many growers are happy with bloom-promoting supplements that include sources of…

  • amino acids
  • humic acids
  • vitamins
  • trace minerals
  • often contain unlisted ingredients (including plant hormones)

I personally don’t use this type of supplement so I can’t recommend a particular one, but some of the most popular cannabis supplements based on this type of formula include…

Note: When possible, try to get all your nutrients and supplements from the same company. This greatly reduces the chance of getting unexpected reactions between the different products. Some companies don’t “play well” together.



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