Dysphagia Knowledge Hub — 吞嚥困難知識庫

IDDSI Level 3 (Liquidised): Preparation Guide, Food Selection, and Testing Methods

Understanding IDDSI Level 3

In the IDDSI framework, Level 3 — Liquidised occupies the boundary between drinks and foods. It is a food texture level — not a liquid level — and describes foods that have been processed to a smooth, pourable consistency that does not require any chewing. Level 3 foods can be drunk from a cup, though they may also be consumed with a spoon.

This distinguishes Level 3 from its neighbours: Level 4 (Pureed) foods hold their shape on a spoon and cannot be poured; Level 2 (Mildly Thick) liquids are thickened drinks, not blended food. Level 3 sits precisely between these two, capturing foods that have been fully liquefied but retain a slightly thicker consistency than mildly thick liquids.

The clinical significance is that Level 3 patients have minimal oral processing ability. They cannot manage lumps, particles, fibres, seeds, or anything that requires mastication. The food must flow without effort and present no risk of bolus fragmentation in the oral cavity.

IDDSI Testing for Level 3

Two standardised IDDSI tests apply to Level 3 foods:

Syringe Flow Test

Using a standard 10 mL syringe:

Fill to the 10 mL mark with the prepared food.
Hold vertically, tip down, and release the plunger for 10 seconds.
Read the remaining volume.

Level 3 result: 1–4 mL remains in the barrel after 10 seconds. If 0 mL remains, the food tests as Level 0–2 (too thin). If more than 4 mL remains, the food tests at Level 4 or thicker.

Spoon Tilt Test

Place a rounded dessert spoon of the food on the spoon.
Tilt the spoon to 45 degrees.
Observe the flow.

Level 3 result: The food slides off the spoon easily and flows freely. It does not hold a peak or mound. It does not leave a thick coating on the spoon. Compare Level 4 (Pureed), which holds its shape on a tilted spoon and requires a tap to dislodge.

Perform both tests at serving temperature. Warm foods tend to be thinner than their refrigerated state; test just before service.

Foods That Liquidise Well

Not all foods can be reliably liquidised to Level 3. The most predictable results come from:

Vegetables: Cooked pumpkin, sweet potato, carrot, potato, beetroot, and butternut squash all blend to a smooth consistency with added liquid. Cook until very soft — steaming or boiling until a fork passes through with no resistance.

Legumes: Split red lentils, yellow split peas, and cooked chickpeas (peeled) blend smoothly. They are nutritionally dense and provide protein alongside carbohydrate, making them particularly valuable for patients at risk of malnutrition.

Fruit: Ripe banana, mango, peach, and pear blend smoothly without fibrous residue. Stone fruits must be stoned; citrus fruits are unsuitable due to membrane fibre.

Cereals and grains: Porridge (oatmeal) cooked to a smooth consistency and thinned with milk or fortified plant milk, smooth cream of wheat, and congee blended after extended cooking can all reach Level 3 with appropriate liquid adjustment.

Dairy and protein: Plain yoghurt without fruit pieces, smooth ricotta, silken tofu, and scrambled egg blended with liquid can achieve Level 3 consistency.

Common Preparation Failures

Fibrous Vegetables

Raw or lightly cooked fibrous vegetables — celery, spinach, asparagus, leek, artichoke, and green beans — contain structural fibres that do not break down in a standard blender regardless of processing time. Even after prolonged blending, these fibres remain as threads or flecks that fail the syringe test and pose an aspiration or choking risk. These vegetables should not be used for Level 3 preparation unless passed through a fine-mesh sieve after blending to remove all fibre.

Meat

Meat is particularly problematic at Level 3. Even lean, well-cooked meat retains myofibrillar proteins that produce a stringy, fibrous, or grainy texture when blended. The result typically tests between Level 4 and Level 5 rather than Level 3, and particle fragments remain even after extended processing. To achieve Level 3 with meat, use a high-powered blender, add substantial cooking liquid or stock, blend for a minimum of 2–3 minutes, and strain through a fine sieve. The resulting product is primarily a meat-flavoured broth with limited protein benefit. Alternatives such as blended legumes, tofu, smooth fish, or egg provide better nutritional yield at Level 3.

Seeds, Skins, and Cores

Tomato seeds, berry seeds, fruit skin, and vegetable skins consistently fail to fully liquidise. Peel all produce before cooking. Strain tomato-based preparations through a sieve. Use seedless fruit varieties where possible.

Temperature and Resting

Foods thicken on standing as starches absorb liquid. A preparation that tests correctly at Level 3 immediately after blending may test as Level 4 after 15–20 minutes at room temperature. Prepare Level 3 foods as close to service time as possible, or re-test consistency after the anticipated standing time.

Nutritional Adequacy at Level 3

Because Level 3 foods are predominantly water by volume, patients on this level are at elevated risk of insufficient energy and protein intake. Clinical strategies to improve nutritional density include:

Fortifying preparations with full-fat dairy, cream, olive oil, or nut butters (smooth only, sieved after blending)
Using oral nutritional supplements at the appropriate liquid level as a base for blending
Working with a registered dietitian to calculate protein and energy targets and audit intake weekly

Prescribing Considerations

Level 3 is appropriate for patients who lack functional oral processing (mastication) but retain adequate pharyngeal swallow function to manage a pourable, smooth bolus. It is typically prescribed for patients with severe oral weakness, absent dentition without adequate prosthesis, significant oral pain, or very early-stage return of oral feeding following extended nil-by-mouth periods.

Patients who require thickened liquids alongside Level 3 foods will need separate liquid prescriptions at the appropriate IDDSI drink level (1, 2, or 3). Food texture and liquid level are prescribed independently in the IDDSI framework.

Summary

IDDSI Level 3 (Liquidised) defines smooth, pourable foods that flow freely but slightly more slowly than mildly thick liquids. It requires no oral processing and is verified by the syringe flow test (1–4 mL remaining) and the spoon tilt test (slides off freely). Foods that liquidise well include cooked root vegetables, legumes, ripe fruit, smooth cereals, and dairy. Common failures include fibrous vegetables, meat, and foods with seeds or skins. Preparation must account for temperature-related consistency changes and the nutritional risk of high water content in processed foods.