Churning

Churning is where liquid becomes frozen dessert—the moment that defines texture, incorporates air, and sets the ice crystal structure. Understanding what happens inside the machine enables consistent results.

What Happens During Churning

1. Heat extraction — Machine wall freezes base on contact
2. Scraping — Dasher removes frozen layer from wall
3. Air incorporation — Dasher whips air into mixture
4. Fat destabilization — Fat globules partially coalesce, trapping air
5. Ice crystal formation — Small crystals disperse throughout
6. Viscosity increase — Mixture thickens as temperature drops

Key Parameters

Parameter	Target	Why It Matters
Base temperature (start)	4°C / 40°F	Cold base freezes efficiently
Draw temperature	–6°C / 21°F	Optimal texture, structure set
Churn time	Variable (15–30 min)	Machine dependent
Overrun	25–35% (gelato), 30–50% (rich ice cream)	Texture and density

Draw Temperature

The most critical parameter.

Temperature	Effect
Warmer than –4°C	Too soft, won’t hold shape, poor structure
–4°C to –5°C	Soft serve consistency
–5°C to –6°C	Optimal gelato draw
–6°C to –7°C	Optimal ice cream draw
Colder than –8°C	Over-churned, butter risk, hard to pack

Note

Eggless bases and sorbets draw warmer at −5°C / 23°F. The absence of egg yolk proteins means these mixes reach the correct set point at a slightly higher temperature.

Measuring Draw Temperature

Method 1: Probe thermometer Insert probe into churning base (carefully, avoiding dasher). Read when mixture reaches thick, soft-serve consistency.

Method 2: Visual cues

• Base pulls away from wall in sheets
• Mixture holds soft peaks
• Dasher shows clear resistance
• Volume has increased noticeably

Method 3: Machine indicators Some machines display temperature or have automatic shutoff.

Machine Types

Pre-Freeze Bowl

Aspect	Details
How it works	Frozen gel in bowl walls provides cold
Prep required	24 hours in freezer
Typical temp	–25°C to –30°C when fully frozen
Churn time	20–25 minutes
Batch capacity	One batch per freeze

Tips:

• Ensure bowl is fully frozen (24 hours minimum)
• Work quickly—bowl warms as it churns
• Place in coldest freezer spot
• Can freeze 2 bowls for back-to-back batches

Compressor Machine

Aspect	Details
How it works	Built-in refrigeration system
Prep required	5–15 min pre-cool
Typical temp	–30°C to –35°C
Churn time	20–30 minutes
Batch capacity	Continuous with cool-down between

Tips:

• Pre-cool machine before adding base
• Allow 10–15 min cool-down between batches
• Machine can overheat with too many consecutive batches

Batch Freezer (Commercial)

Aspect	Details
How it works	Powerful refrigeration, fast scraping
Typical temp	–35°C to –40°C
Churn time	8–12 minutes
Batch capacity	Variable, often 2–6 quarts

Tips:

• Pre-cool chamber
• Follow manufacturer guidelines
• Produces superior ice crystal structure

Churning Process

Verify Base Temperature

Base should be at 4°C / 40°F. If frozen, thaw in refrigerator. If warm, chill further.

Prepare Machine

Pre-freeze bowl should be fully frozen (shake—no liquid sound).

Compressor machine should be pre-cooled (run empty for 5–15 min).

Pour Base

Pour base into running machine. Pouring into a running dasher incorporates initial air.

Churn

Let machine run. Don’t open lid unnecessarily—cold air escapes.

Monitor Progress

Check at 15 minutes, then every 5 minutes. Look for:

• Increasing thickness
• Volume expansion
• Resistance on dasher

Test for Draw

When mixture appears ready, check temperature with probe or evaluate visually.

Add Mix-Ins (If Using)

In final 30 seconds, add frozen mix-ins through feed hole.

Stop and Transfer

Stop machine immediately at draw temperature. Transfer quickly to storage container.

Overrun Control

Measuring Overrun

Overrun % = [(frozen volume – base volume) / base volume] × 100

Practical measurement:

1. Note base volume before churning
2. Measure or estimate frozen volume
3. Calculate percentage increase

Controlling Overrun

To Increase Overrun	To Decrease Overrun
Churn longer	Churn shorter
Fill machine less	Fill machine more
Start with warmer base	Start with colder base
Use faster dasher speed	Use slower dasher speed

Target Overrun by Product

Product	Target
Dense gelato	20–25%
Standard gelato	25–35%
Premium ice cream	40–60%
Standard ice cream	60–80%
Economy ice cream	80–100%
Sorbet	15–25%

Troubleshooting

Problem	Cause	Solution
Won’t freeze	Bowl not frozen; base too warm	Freeze bowl 24+ hrs; chill base
Freezes too fast	—	This is usually good; be ready to transfer
Takes forever	Bowl warming; machine underpowered	Use fresh bowl; pre-cool longer
Too fluffy	Over-churned	Stop earlier; fill machine more
Too dense	Under-churned	Churn longer; fill machine less
Butter forming	Over-churned; too cold	Stop immediately; check draw temp
Icy texture	Under-churned; formulation issue	Churn longer; check PAC
Grainy texture	Large ice crystals	Ensure cold equipment; check formula

Butter Formation Recovery

If base starts forming butter:

1. Stop immediately
2. Transfer what you have—texture compromised but edible
3. Cannot reverse—fat structure has broken

Prevention:

• Don’t exceed –8°C draw temperature
• Don’t churn aged base more than 24 hours old (fat over-crystallized)

Batch-to-Batch Consistency

For consistent results across batches:

Factor	Control Method
Base temp	Always start at 4°C
Machine temp	Pre-cool consistently
Draw temp	Use thermometer every batch
Fill level	Measure by weight or volume
Churn time	Record and compare

Transfer Speed

Time from draw to freezer matters.

Time	Ice Crystal Impact
Under 2 min	Optimal
2–5 min	Acceptable
5–10 min	Noticeable degradation
Over 10 min	Significant crystal growth

Tips for fast transfer:

• Have container ready and pre-chilled
• Have freezer open and cleared
• Work with partner if making multiple batches
• Don’t stop to photograph until product is in freezer

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