Using mango pulp in beer without infection or muddy haze

Choosing the pulp

Indian canned mango pulp is usually made from Alphonso, prized for its intense aroma, or Totapuri, which is tangier and cheaper and often blended. Read the tin before you buy a pallet.

• Sweetened or unsweetened. Many retail pulps contain added sugar. That sugar ferments too, so it changes your ABV and your carbonation.
• Preservatives. Some pulps contain preservatives such as sodium benzoate or sulphites, which can slow or stop yeast. For brewing, buy pulp with no added preservatives, typically sold as aseptic or thermally processed.
• Brix. Ask the supplier for the Brix (sugar content) of the lot. You need it to calculate the extra sugar you are adding.
• Food-grade supplier. A supplier who can give you a specification and lot number, not loose tins from a wholesale market.

How much to use

Fruit beers use a wide range. Many brewers work somewhere between about 60 and 250 g of pulp per litre of beer, lighter for a hint of mango in a wheat beer and heavier for a fruit-forward sour or IPA. On a 1,000 litre batch that is 60 to 250 kg. Mango aroma is gentle compared with its colour and body, so a beer that looks very mango can still taste only faintly of it. Trial at two or three rates on a small scale before committing a tank.

When to add it

In the kettle at flameout or whirlpool. Heat sanitises the pulp. You lose some fresh aroma and gain cooked fruit notes. The solids also add to trub losses.

In the fermenter after the main fermentation. The most common choice. The beer already has alcohol and a low pH, which protects against most spoilage organisms. The yeast ferments the fruit sugar and much of the aroma survives.

At packaging or in the bright tank. Only if the product is pasteurised afterwards or the sugars will not ferment. Unfermented fruit sugar in a can is a refermentation risk.

Pulp that has been open for hours in a warm brewery is the infection risk, not the tin itself. Open tins right before dosing, sanitise the outside of the tin and the opener and transfer through sanitised equipment. Our guide to adding fruit to beer covers sanitation in more detail.

Refermentation and pressure

Mango pulp sugar ferments. Adding fruit to finished beer restarts fermentation, raises the alcohol a little and makes CO2. If that happens in the tank, fine. If it happens in a sealed can or bottle, pressure can build well beyond what the package was designed for. An overpressurised can or bottle can burst.

Before packaging, check that gravity has been stable for at least two or three days and taste for sweetness. Run a forced fermentation test on a sample: keep it warm with fresh yeast and check whether gravity drops further. If it does, the beer is not ready to package.

Dealing with muddy haze

Mango pulp brings fine fibre, pectin and protein. Pectin in particular forms a stubborn haze and can make the beer look like juice. Some haze suits a mango wheat beer or a hazy IPA. A brown, murky beer does not.

• Add a pectinase enzyme with the pulp, following the supplier's dose, so pectin is broken down during fermentation.
• Give the fruit solids time to settle, then cold crash hard before transfer.
• Rack carefully off the fruit layer. A centrifuge, if you have one, helps on larger batches.

Our guide to beer haze causes explains pectin haze alongside protein and yeast haze.

Infection signs to watch

A mango beer that develops a film on top, vinegar or solvent aroma, ropy texture or keeps losing gravity long after it should have stopped is telling you something. Wild yeast and bacteria love fruit. Take a sample for plating if you have a lab. Do not blend a suspect tank into a good one. Our guide to infection and bacteria in brewing covers the common culprits.

Losses and costing

Pulp is expensive. Some of the beer also stays behind with it. Fruit solids trap beer at the bottom of the tank, so expect noticeably more loss on a fruit batch than on a normal one. Measure it on your first few batches and put it into your recipe costing, along with the cost of the enzyme and the extra tank time. Fruit beers that look profitable on a recipe sheet often look different once losses are counted.

Fruit beers are where microbiology, enzyme chemistry and package safety meet. Each one is manageable once you understand the mechanism behind it.

Common questions

Which mango pulp is best for beer?

Pulp with no added preservatives from a food-grade supplier. Alphonso gives the strongest aroma. Check whether sugar was added and ask for the Brix.

When should I add mango pulp?

Most brewers add it after the main fermentation, when alcohol and low pH protect the beer and the yeast can ferment the fruit sugar.

Why is my mango beer so hazy?

Mango brings pectin, fibre and protein. A pectinase enzyme, settling time and a hard cold crash all help.

Can mango beer burst cans?

Yes, if fruit sugar is still fermenting when the beer is packaged. Confirm stable gravity and run a forced fermentation test first.