Liquid Food BLOOD & LIVER

Applied Biochemistry for Feeding Stimulation in Carp Fishing

Blood & Liver Liquid Food 🧪🩸

Not just another attractor, but a biochemically active feeding signal designed for modern carp bait making.

This pre-digested liquid combines animal blood and fresh liver, two extremely rich raw materials, broken down through enzymatic hydrolysis into free amino acids, soluble peptides and biogenic amines — the same compounds carp naturally detect as high-energy food sources.

The result is a dense, dark red-brown liquid capable of releasing a powerful chemical trail in the water, stimulating carp chemoreceptors and triggering a real feeding response.

In the article you’ll find:

• the full Blood & Liver liquid food recipe
• the role of enzymes, salt and acids in protein hydrolysis
• how to control pre-digestion and maturation
• how to use it on boilies, pellets, stick mixes and spod mixes

A deep dive into the scientific side of bait making.

Welcome to the laboratory.

 

In modern carp fishing, it is no longer enough to simply talk about “attractors.”
To build a truly effective feeding stimulus we must start thinking in terms of biochemistry, nutritional signals and molecular diffusion in water.

This is exactly the concept behind the Liquid Food Blood & Liver project.

This recipe is not just another protein liquid: it is a pre-digested nutritional extract, designed to release into the water extremely high concentrations of free amino acids, soluble peptides and biogenic amines — the very same molecules that carp naturally recognize as powerful feeding signals.

At the core of the process are two raw materials with exceptional nutritional value:

• Animal blood, one of the most concentrated natural sources of highly soluble proteins and nitrogen compounds

• Fresh liver, a metabolic organ extremely rich in enzymes, peptides and micronutrients

Through a controlled process of enzymatic pre-digestion and protein hydrolysis, these complex proteins are progressively broken down into smaller, highly bioavailable molecules. The result is a dark, dense reddish-brown liquid with an extremely powerful chemical signature — a true cocktail of feeding signals.

In water, this type of solution does not work merely as a flavour. It acts as a real nutritional stimulus. Free amino acids and amines disperse quickly, creating a highly recognizable chemical trail capable of activating carp chemoreceptors even at distance.

The philosophy behind this recipe is simple:

not masking the bait with artificial smells, but simulating a biologically authentic food signal.

In this article we will analyse in detail:

• the raw ingredients used

• the role of salt, acids and digestive enzymes in the hydrolysis process

• how to manage pre-digestion time and stabilization

• how to obtain a highly soluble and stable liquid food

• and most importantly how to use it with boilies, stick mixes, pellets and spod mixes

If you are interested in the scientific and advanced side of bait making, this recipe represents one of the most effective ways to transform raw ingredients into a high-attraction liquid nutritional signal.

In the next chapter, we step into the laboratory.

Let's prepare Blood & Liver Liquid Food.

Blood: a Powerful Feeding Trigger

I still remember my very first fishing license and a passage in the regulations that explicitly prohibited the use of blood as a substance “capable of stunning fish.”

Years later I realized that the term stunning had nothing to do with animal safety. It referred instead to the feeding frenzy triggered by the large amount of water-soluble chemical compounds released by blood — compounds that reach the sensory receptors of opportunistic fish such as carp with incredible efficiency.

Liver also owes part of its attractivity to being naturally rich in blood, but that is not the only reason.
It is a primary storage organ containing valuable essential amino acids, organic sugars such as glycogen, and fatty acids.

The synergy between blood and liver creates an extremely intense biochemical profile, perfect for producing a powerful liquid food attractant for boilies, pellets, method mixes and groundbaits.

Finding Blood

Obtaining blood is not always easy, and the most practical solution is often the livestock and pet food industry, where it is commonly used as an ingredient in feeds and palatants.

I used to buy the one sold for dog nutrition (BARF-style diets). It is typically available in two forms:

• Liquid blood, convenient but requiring freezing

• Blood powder, a very fine dark powder, almost black in colour due to red blood cells and oxidized hemoglobin

Blood powder is pasteurized, making it hygienic and safe to handle.

The recipe below uses blood powder, but using liquid blood simply requires adjusting the quantity of added liquids.

Choosing the Liver

One of the most common questions I receive is whether the animal source of the liver makes a difference.

Pork, beef, goat, chicken — all are perfectly suitable.
There are slight differences in colour and fibrous structure, but from a bait-making perspective they perform very similarly.

My advice is simple: buy the cheapest one available — usually pork or chicken.
And if someone offers it to you for free… even better!

Cost vs Commercial Liquids

Producing this liquid food is also economically advantageous.

At most, one litre of homemade liquid food costs around €6–8, while the cheapest commercial equivalent often costs €20 or more per litre.

If you produce a lot of boilies, or if you want to create highly attractive baits, the difference becomes significant.

Being able to include 200 ml of such a powerful organic liquid per kilogram of bait mix dramatically increases the feeding stimulus for large carp.

The Role of Vinegar

Another key ingredient is vinegar.

You can use:

• apple cider vinegar

• fruit vinegar

• alcohol vinegar (more economical for large batches)

A good natural vinegar contains active mother cultures and interesting ester compounds, which not only lower the pH but also introduce additional attractant molecules.

Lowering the pH serves two main purposes:

1. Improving the enzymatic pre-digestion process

2. Increasing the stability and shelf life of the product

Vinegar also helps liquefy the mixture, facilitating the action of enzymes and salt.
The ideal consistency should be that of a fluid cream.

Salt: Stabilization

Salt is used at 10–15% of the total weight.

Its role is to stabilize the mixture, preventing uncontrolled decomposition and improving long-term preservation.

If liquid blood is used instead of powder (therefore reducing the amount of vinegar), the salt percentage should be increased to around 20%.

Digestive Enzymes

Digestive enzymes are another key component.

The most commonly used enzymes are:

• Bromelain

• Papain

• Proteases

Bromelain powder is widely available and usually sold with a value expressed in GDU (Gelatin Digesting Units), which indicates enzymatic activity.

A product above 2000 GDU is ideal — the higher the value, the faster and more efficient the digestion process.

Alternatively, digestive supplements sold in nutrition stores can be used. Many contain protease, lipase and amylase. Simply crush 5–6 tablets per kilogram of raw material.

The Recipe

Ingredients

• 500 g blood powder

• 500 g liver

• 100 g salt

• 5 g digestive enzymes

• Vinegar as needed to obtain a fluid consistency

The Process

The process is very simple.

Blend the liver until smooth, then gradually incorporate the blood powder and vinegar until the mixture reaches the consistency of a fluid cream.

Add the salt and enzymes, continuing to mix with the blender and adjusting the consistency with additional vinegar if necessary.

Transfer the mixture into a sealed glass jar and allow it to mature at 30–35°C for 48 hours.
If the temperature drops below 20°C, the process may take about a week.

At this stage the first phase is complete. From here on, the mixture becomes stable and continues to mature over time, gradually transforming into a fermented hydrolysate.

Personally, I prefer letting it mature for at least 20 days before using it.

(👉 If you want to dive deeper into the science behind these processes, read my article explaining the difference between pre-digestion and fermentation in bait making.)

Liquid and Powder Forms

Extending the maturation process also allows you to obtain two products:

• a concentrated liquid hydrolysate

• a solid dehydrated powder

After about 30 days, filter the mixture through gauze while applying pressure.

This produces:

• a concentrated liquid fraction

• a humid pulp

The pulp can be spread on baking paper in a thin layer (less than 1 cm) and dried in a ventilated area. Once dry, it can be ground into a highly attractive protein powder.

Dosage and Applications

The liquid hydrolysate can be used at:

• 30–200 ml per kg of boilie mix

For extremely attractive pellets, it can be used to bind groundbait (for example Sensas 3000 Carp), diluted 50% with water.

Create a firm dough, pass it through a meat grinder to produce small cylinders, and let them dry in a ventilated area. These are excellent for PVA sticks and bombs.

PVA-Friendly Dilution

For all PVA-friendly applications, the liquid food should be diluted 30–50% with propylene glycol or vegetable glycerin.

In practical fishing terms:

• Propylene glycol produces a more fluid solution, improves dispersion regardless of water temperature and enhances product stability.

• Vegetable glycerin creates a denser and heavier liquid, slowing down diffusion and increasing persistence around the bait.

I hope this super booster will inspire you to experiment and push your bait recipes to the next level.

 

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