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Harvesting and storing

Last updated: July 17, 2026 Español Русский

The pear is one of the most popular fruits worldwide, prized for its delicate texture, sweet taste, and aroma. However, growing a good crop is only half the battle. To enjoy pears for many months, it is essential to correctly determine the harvest time and create suitable storage conditions. According to FAO, global pear production is about 25 million tons annually, and a significant portion of this harvest is lost due to mistakes during harvesting and storage (FAO, 2014). This article will help you avoid common errors and preserve your fruit with minimal losses.

1. Fruit Ripening

To understand when to harvest pears, you need to know what happens to the fruit during ripening. In fruit biology, three key stages are distinguished: physiological maturity, harvest maturity, and eating maturity.

Physiological Maturity

Physiological maturity is the stage of fruit development when the seeds are fully formed and capable of producing a new plant. For the grower, this stage is important because from this point on, the fruit acquires the ability to continue ripening after being removed from the tree (Westwood, 1993). This property is characteristic of so‑called climacteric fruits — which include pears, apples, bananas, and tomatoes.

A pear that has reached physiological maturity can undergo the entire ripening process in storage. This is the basis of long‑term pear storage technology: we pick them while firm and not yet tasty, and then they “finish” ripening in a cool place.

Harvest Maturity

Harvest maturity is the state of the fruit when it is not yet ready to eat, but has reached the stage where it can be picked from the tree for subsequent ripening during storage (Jackson, 2003; Westwood, 1993).

Determining harvest maturity is the key moment for the grower. If you pick a pear too early, it will not ripen properly: it will remain hard, tasteless, and may shrivel during storage. If you are late with harvest, the fruit will overripen on the tree, its flesh will become mealy, and it will not keep long.

What determines harvest maturity:

  • Growth and accumulation of organic substances are completed in the fruit.
  • The fruit has reached the size and shape typical for the variety.
  • The seeds begin to darken but are not yet fully coloured.
  • The starch accumulated in the fruit starts converting into sugars.
  • The stem separates easily from the fruiting branch.

It is important to understand: harvest maturity for summer, autumn, and winter varieties occurs at different times and is determined by different indicators. In summer varieties, harvest maturity almost coincides with eating maturity; in winter varieties, the gap between them can be several months (Jackson, 2003).

Eating Maturity

Eating maturity is the state when the fruit is fully ready for consumption: it has the typical colour, aroma, juicy and sweet flesh for the variety (Westwood, 1993).

In summer pear varieties, harvest and eating maturity may coincide or differ by only a few days. In autumn varieties, the gap is 1–3 weeks. In winter varieties, eating maturity occurs 2–3 months after harvest and can extend throughout the storage period until spring (Mandal et al., 2021).

Important: The pear is one of the few fruits that we harvest unripe and allow to ripen in storage. Correct determination of harvest maturity is the foundation of successful long‑term storage.

Why Does the Pear Continue to Ripen After Harvest?

This process is based on the climacteric rise — a sharp increase in the respiration rate of the fruit, accompanied by ethylene production that triggers ripening processes (Jackson, 2003; Westwood, 1993).

Ethylene is a gaseous phytohormone produced by fruits and acts as a signal to start ripening. In the pre‑climacteric period, pears produce very little ethylene. When the fruit reaches a certain stage of maturity, a chain reaction starts: ethylene is released, which stimulates further ethylene production, and the process becomes irreversible (Jackson, 2003).

After harvest, pears continue to respire and emit ethylene. This is why:

  • Pears picked too early cannot initiate the climacteric rise and will not ripen.
  • Pears picked too late have already started this process on the tree and will overripen quickly.
  • Lowering the temperature slows down respiration and the ethylene response, allowing storage for months.
  • Storing pears near apples or other ethylene‑producing fruits accelerates ripening (this can be used for faster conditioning).

Thus, by controlling temperature and atmospheric composition, the grower can manage the speed of pear ripening after harvest.

2. When to Harvest

The most common question from growers is: “When should I pick the pears?” There is no universal answer because the timing depends on the variety, region, weather of the season, and even tree age. However, there are reliable indicators that will help you avoid mistakes.

Signs of Harvest Maturity: What to Check

It is best to determine harvest maturity by a combination of signs — none of them alone gives a complete guarantee (Westwood, 1993; Jackson, 2003).

1. Seed Colour

Cut several typical fruits lengthwise and look at the seeds. Scoring scale (Tarasov et al., 1981):

  • 1 point – seeds white, uncoloured (fruit immature)
  • 2 points – tips of seeds begin to brown
  • 3 points – seeds coloured halfway
  • 4 points – ¾ of seeds coloured
  • 5 points – seeds completely brown (fruit overripe for storage)

For long‑term storage, optimal is when seeds are coloured at 2–3 points. For summer varieties that will be consumed immediately, a higher degree is acceptable (Mandal et al., 2021).

2. Ground Colour of the Skin

In most varieties, the green background gradually turns yellow as they ripen. Summer varieties turn yellow faster; winter varieties retain a greenish hue longer. Important: the presence of a red blush is not an indicator of maturity – it depends on sunlight and may appear long before harvest maturity (Jackson, 2003).

3. Ease of Stem Separation

A ripe fruit separates easily from the branch with a slight upward twist (Tarasov et al., 1981). If the stem comes off with difficulty or tears out with part of the wood – the fruit is not yet ready for harvest. This sign is especially important for summer varieties.

4. Starch‑Iodine Test

Starch accumulated in the fruit turns into sugars during ripening. Iodine stains starch blue‑black, and the degree of staining on a cross‑section can indicate maturity (Westwood, 1993). How to perform:

  • Cut several fruits transversely (at the widest point)
  • Dip the cut surfaces for 5 seconds in a 1% iodine solution in potassium iodide (3 g iodine + 1 g potassium iodide per 100 ml water)
  • Remove and blot with filter paper
  • Assess the blackening on a scale from 1 to 5 (Tarasov et al., 1981)

Recommended scores for harvest:

  • 1–2 points – only areas just under the skin are stained (fruit close to eating maturity) – for summer varieties and fruits to be sold or processed immediately.
  • 2–3 points – about half of the cut surface stained – optimal for autumn and some winter varieties for medium‑term storage.
  • 3–4 points – most of the cut stained, but the core remains light – ideal for long‑term storage of winter varieties (Jackson, 2003; Westwood, 1993).

The starch‑iodine test is one of the most reliable and accessible methods for the home gardener.

5. Flesh Firmness (Penetrometer)

A professional method – measuring the force required to insert a probe into the peeled flesh. For pears, a probe diameter of 7.9 mm (5/16 inch) is used. Optimal values vary among varieties (Mandal et al., 2021; Jackson, 2003):

Variety Firmness at harvest (Newtons)
Bartlett (Williams) 67–84
Bosc 63–72
Anjou 58–67
Conference 62–72
Duchess d’Angoulême 45–50

For the home gardener, it is easier to rely on other indicators, but if you have a penetrometer – use it.

6. Number of Days from Full Bloom

This is an auxiliary guide. On average (Mandal et al., 2021):

  • Summer varieties: 90–100 days
  • Autumn varieties: 100–120 days
  • Winter varieties: 120–150 days

However, the timing varies greatly depending on weather, so use this number only for preliminary planning.

Differences Between Summer, Autumn, and Winter Varieties

Pears are grouped by ripening time, and the harvesting approach differs for each group.

Summer Varieties (Bartlett / Williams, Clapp’s Favorite, Ilyinka)

  • Harvest and eating maturity almost coincide.
  • Harvest when fruits begin to turn yellow and become slightly sweet in taste.
  • Store for a short time – 1–2 weeks in a regular refrigerator.
  • For local consumption, it is better to wait for full ripening on the tree; for transport, pick 2–3 days earlier.
  • Overripe summer pears become mealy and spoil quickly (Westwood, 1993).

Autumn Varieties (Conference, Bosc, Duchess)

  • Harvest maturity occurs 1–3 weeks before eating maturity.
  • Pick when seeds have begun to darken (2–3 points) and the skin colour begins to yellow.
  • After harvest, they require ripening at room temperature for 7–14 days.
  • Can be stored for 1–3 months at +1…+2 °C.
  • Overripening on the tree reduces their storage ability (Jackson, 2003).

Winter Varieties (Anjou, Late Conference, Winter Williams)

  • Harvest maturity occurs when the fruit is still green and firm.
  • Optimal harvest at 3–4 points on the starch‑iodine test.
  • Eating maturity occurs after 2–4 months of cold storage.
  • Only properly harvested winter pears can keep until spring without quality loss.
  • If picked too early, they will not ripen and will shrivel; if too late, they will soften in storage and rot (Westwood, 1993; Mandal et al., 2021).

Effect of Weather Conditions on Harvest Timing

The weather in the growing season significantly shifts ripening dates (Jackson, 2003; Westwood, 1993).

  • Warm spring‑summer weather accelerates ripening by 5–10 days. Fruits are harvested earlier than normal calendar dates.
  • Cold and rainy summer delays ripening. Pears may not accumulate enough sugars and aroma, and ripening is prolonged.
  • Hot and dry weather during fruit fill often leads to premature ripening and reduced storability.
  • Heavy rainfall just before harvest increases the risk of cracking and watery flesh. Such pears store poorly – they are better picked 5–7 days earlier and used for processing.
  • Night frosts before harvest can damage the skin and flesh – such fruits will not store.

General rule: in a hot year, harvest pears a few days earlier; in a cold year, later. Rely not on the calendar but on the specific indicators described above.

Summary for the Grower

1. For long‑term storage, pick winter pears when they are firm, green‑skinned, and score 3–4 on the starch‑iodine test.

2. For medium‑term storage (1–3 months) – autumn varieties at 2–3 points, when seeds are half‑brown.

3. For immediate use – summer varieties: wait for slight yellowing and sweet taste.

4. Never rely on a single indicator – check a combination: stem separability, seed colour, starch test.

5. In a rainy summer, harvest earlier – moisture reduces storability.

6. Remember: too early harvest leads to weight loss (fruit grows until the last moment) and loss of flavour; too late harvest leads to shedding and rotting.

3. Harvesting Rules

Proper harvesting is as important as growing. A carelessly picked pear may fail to ripen, rot, or lose flavour even before reaching the table. This chapter provides simple but important rules to preserve every fruit.

Best Time of Day and Weather for Harvesting

  • Morning is the best time. Harvest pears early in the morning, after the dew has dried but before the sun heats the fruit. Cool fruits are more resilient, less prone to damage, and respire more slowly after picking (Westwood, 1993). If you harvest on a hot day, fruits quickly lose moisture, become limp, and store worse.
  • Dry weather. Never pick pears during rain or immediately after. Wet fruits are more easily damaged, fungal diseases develop faster on them, and wet skin is more susceptible to mechanical injury (Agustí, 2010).
  • Fruits should be dry. If there are water drops on the pears, let them dry naturally – do not wipe them, so as not to damage the waxy bloom.
  • In a rainy season, try to harvest in a gap between rains – even if fruits seem slightly less ripe, it is better to pick them earlier than to lose them from cracking and rots.

Harvesting Technique: How to Pick Without Damaging

Pears are delicate fruits. Every press of a finger leaves a dent that will darken over time and become a focus of rot. Follow these rules:

1. Hold the fruit in the whole palm. Do not squeeze with fingers – place your palm under the fruit, cradling it from below. Put your index finger on the stem at its attachment point to the branch (Tarasov et al., 1981).

2. Twist the fruit upward. With a gentle motion, turn the pear upward around its axis – a ripe fruit will easily separate from the fruiting branch. Do not pull or jerk! With proper picking, the stem remains intact (Mandal et al., 2021).

3. Preserve the stem. Pears for storage must have the stem. If the stem is torn out, rot pathogens enter the wound, and the fruit spoils quickly. Fruits without stems are not suitable for long‑term storage (Potapov et al., 2000).

4. Do not tear, but “unscrew”. Think of it as unscrewing a lid from a jar – this motion ensures a clean break without skin damage.

5. Pick in two steps for tall trees. If working from a ladder, first carefully separate the fruit from the branch, then place it in a basket or bucket. Do not throw or pour pears from a basket into a box – this causes bruising.

6. Start from the lower branches and work upward. This way you will not accidentally knock off already ripe fruits from the upper branches.

Preparation for Harvesting

  • Trim your nails or wear thin cotton gloves – long nails easily scratch the thin pear skin (Tarasov et al., 1981).
  • Prepare containers in advance. You will need shallow baskets, crates, or plastic containers with smooth walls. Container depth – no more than 30–40 cm, so that lower fruits are not crushed (Potapov et al., 2000). Line the bottom and sides with soft paper or wood shavings.
  • Tie a cloth to the basket or put a shoulder strap on – so your hands are free for careful picking.
  • Do not use plastic bags for harvesting – fruits “sweat” in them, spoil quickly, and the skin is damaged by rubbing against each other.
  • Separate containers for each tree. If you mix fruits from different trees (different maturity, different varieties), sorting becomes more difficult and some fruits may spoil.

Preventing Mechanical Damage

Damage is the main cause of pear losses during storage. Any scratch, dent, or puncture is an entry point for fungi and bacteria (Agustí, 2010).

  • Avoid impacts. Never throw pears into containers – even from a height of 10 cm, impact causes internal damage that is not visible externally but will appear after a few weeks as flesh browning.
  • Pack pears “cap‑down” – stem down, so they do not press on each other. Place wood shavings or soft paper between layers.
  • Do not fill containers to the brim. Leave 5–7 cm to the edge so that when carrying and transporting, the top fruits are not pressed down by the lid or other boxes.
  • Use soft padding in the container – wood shavings (preferably from hardwoods, resin‑free), paper napkins, or special fruit grids.
  • Do not clean the waxy bloom from the fruits – it is a natural protection against evaporation and diseases. Do not wipe pears with a cloth during harvest!

Typical Harvesting Mistakes

Mistake 1: Harvesting too early or too late. We covered this in detail in the previous chapter. Add only: if in doubt, it is better to wait 2–3 days and check the indicators again than to pick under‑ripe fruits that will never become sweet (Jackson, 2003).

Mistake 2: Harvesting wet fruits. Wet skin is more fragile, easily damaged, and diseases develop faster on it. Always wait until the fruits and tree are dry after dew or rain (Westwood, 1993).

Mistake 3: Using pickers on long poles without cushioning. If using a fruit picker, line the inside with foam rubber or cloth – the hard edge damages the skin. Never shake pears onto the ground or into rigid containers.

Mistake 4: Storing damaged fruits together with healthy ones. Any pear with a crack or dent releases ethylene and accelerates ripening of neighbours, and also serves as a source of fungal spores. Such fruits should be set aside immediately for processing (Agustí, 2010).

Mistake 5: Mixing varieties and ripening groups. Different varieties have different storage lives, and early pears placed next to winter ones will accelerate their ripening. Sort immediately.

Mistake 6: Leaving harvested pears in the sun for a long time. Direct sunlight heats the fruits, increasing respiration and accelerating ageing. After harvesting, move the crop to shade or a cool place as soon as possible (Westwood, 1993).

What to Do Immediately After Harvest

  • Move the crop to shade and cool it as quickly as possible. Each hour of delay at +20 °C reduces storage life by a week. If you do not have a cold room, place the boxes in the coolest place – a cellar, basement, or shaded shelter.
  • Sort the pears on the same day (see next chapter). The sooner you separate damaged fruits from healthy ones, the lower the risk of infecting the entire batch.
  • Do not wash pears before storage! Water washes off the protective waxy layer and introduces disease spores into micro‑cracks. Wash fruits only immediately before consumption or processing (Potapov et al., 2000).

Summary for the Grower

  • Harvest in dry weather, in the morning, after dew has dried but before the sun is hot.
  • Hold the fruit in your palm, separate with a gentle upward twist, preserve the stem.
  • Do not throw, do not crush; pack in shallow containers with soft padding.
  • Always separate damaged fruits from healthy ones.
  • Cool the harvested crop as quickly as possible – this is the main condition for preservation.
  • Do not wash pears before storage.

4. Sorting the Harvest

Sorting is not just “putting fruits into piles”. It is a key step that determines how many pears you can preserve, how many to process, and how many, unfortunately, you will lose. Proper sorting immediately after harvest prevents mass infection of healthy fruits and extends their storage life (Agustí, 2010; Potapov et al., 2000).

Why Sort Immediately After Harvest

  • To prevent the spread of diseases. One rotten fruit can spoil an entire box, especially if it is in closed containers. Fungal spores spread quickly through the air and by contact.
  • To separate by purpose. Pears intended for long‑term storage must be of flawless quality. Slightly damaged or under‑ripe fruits should be processed or used soon.
  • To facilitate monitoring. While sorting, you also assess the overall condition and can notice problems early (e.g., signs of diseases or pest damage).
  • To save space. Do not occupy storage space with fruits that will not survive the winter anyway.

Sorting Groups

The entire harvest should be divided into three main groups (Westwood, 1993; Mandal et al., 2021):

1. Pears for Long‑Term Storage (Select Grade)

These fruits must meet the strictest requirements:

  • Undamaged, intact skin – no scratches, dents, cracks, or punctures.
  • Presence of stem – essential, otherwise the fruit rots quickly at the base.
  • Correct maturity – for winter varieties (3–4 points on starch‑iodine test), for autumn (2–3 points).
  • Uniform size and colour – within a batch, fruits should be roughly similar in size so they ripen evenly.
  • No signs of disease – even the smallest spot may be the start of rot.

Such pears are carefully packed in containers, cushioned with soft material, and placed in storage. They are handled as little as possible until eating maturity is reached.

2. Pears for Processing and Early Consumption

These include fruits that are not suitable for long storage but are still good to eat or process:

  • Slightly damaged – with small dents, scratches, but no signs of decay. These should be used within 1–2 weeks or processed: make jam, preserves, compote, drying, juice.
  • Slightly under‑ripe – if accidentally picked early, they can be ripened at room temperature (but not all varieties ripen well after very early picking).
  • Off‑grade size – too small or too large fruits that are inconvenient to pack in standard containers but are still tasty.

These pears are not placed in the common storage so they do not become a source of problems for the select fruits.

3. Damaged and Diseased Fruits (Cull)

These are fruits that cannot be eaten or processed without severe cutting of affected parts:

  • With obvious rot – soft, watery, with mould or off‑odour.
  • Severely bruised – with broken skin and damaged flesh.
  • Pest‑damaged – with larval tunnels or signs of activity.
  • With deep cracks through which disease spores have entered.

Such fruits should be disposed of immediately (bury in a compost pit, but not near the trees) or fed to animals if safe. Never leave them near healthy fruits.

How to Sort Properly: Step‑by‑Step Instructions

1. Prepare several types of containers – boxes for select fruits, separate containers for processing, and a bucket or bag for cull.

2. Work in a well‑lit place to see all defects.

3. Examine each fruit from all sides. Turn the pear in your hands, paying attention to the calyx (top) and the base (stem attachment) – these are common starting points for rot.

4. Check for the presence of the stem. If it is torn out – set aside for “processing” or “cull” depending on condition.

5. Discard fruits with any dark spots, soft areas, or fermentation smell.

6. Sort by size (not necessarily millimetre‑perfect, but roughly separate large from small). This helps with more uniform packing and ripening control.

7. Wash hands and tools between batches, especially if you have handled diseased fruits, to avoid transferring infection to healthy ones.

What to Do with Stem‑Less Fruits

Pears without stems are not suitable for long‑term storage – decay pathogens enter through the open wound (Potapov et al., 2000). However:

  • If the fruit is intact and ripe – eat it within a few days or process it.
  • If the fruit is under‑ripe but has no other damage – place it separately for ripening at room temperature and use it first.
  • Never put such fruits into the common storage.

Sorting by Maturity Within a Single Batch

Even fruits from the same tree may differ in maturity (Westwood, 1993). For storage, it is better to select fruits of the same maturity in each container unit. If pears of different maturities are placed in one box, the more mature ones will produce more ethylene and accelerate the ripening of the less mature ones, leading to unevenness and loss of flavour (Jackson, 2003).

During sorting, you can additionally check maturity with the starch‑iodine test (see chapter 2) and divide fruits into groups: for long storage (3–4 points), for medium (2–3 points), and for immediate use (1–2 points).

Container Quality for Sorted Fruits

  • For select fruits, use clean, dry boxes free of foreign odours. Line the bottom and sides with soft paper or dry wood shavings.
  • Do not use boxes that previously held diseased fruits without thorough disinfection.
  • For processing fruits, you can use simpler containers, but they must also be clean and not too deep.

Summary for the Grower

  • Sort pears on the day of harvest, without delay.
  • Divide into three groups: select for storage, for processing/quick use, and cull.
  • For storage, keep only intact fruits with stems, no spots or signs of disease, of uniform maturity.
  • Stem‑less fruits, those with scratches and dents – for processing or early consumption.
  • Rotten and severely damaged fruits must be removed immediately and disposed of.
  • Sort by size and maturity to ensure even ripening.
  • Use clean containers.

5. Storage Conditions

You have harvested correctly, picked at the right time, and sorted thoroughly. Now the main task is to create conditions in which they will “sleep” and slowly ripen, preserving flavour and aroma until you decide to eat them. The pear is a living organism; even after harvest it respires, loses moisture, and gradually changes. Our task is to slow these processes as much as possible (Westwood, 1993; Jackson, 2003).

Storage Temperature

Temperature is the most powerful tool for controlling pear quality during storage.

The lower the temperature, the slower the fruit respiration and the longer they store. For most pear varieties, the optimal storage temperature is in the range of –1 to 0 °C. At this temperature, physiological processes are slowed to the maximum, but the fruits do not freeze (Westwood, 1993; Hochmuth & Sideman, 2023).

Why –1…0 °C:

  • Respiration rate at 0 °C is about 3 times lower than at +10 °C and 10 times lower than at +20 °C (Jackson, 2003).
  • Ethylene production – the ripening hormone – is slowed.
  • Activity of enzymes that cause softening and browning is reduced.
  • Development of pathogens (moulds and bacteria) is slowed.

Important nuances:

  • Freezing point of pears depends on sugar content and is approximately –1.5…–2.5 °C. If fruits freeze, their flesh becomes glassy, and after thawing it becomes watery and tasteless. Therefore, do not allow temperature to drop below –1.5 °C (Westwood, 1993).
  • Early and summer varieties (Bartlett, Clapp’s Favorite) are more sensitive to cold and may suffer chilling injury at temperatures below 0 °C, so they are stored at +1…+2 °C, but their storage life is shorter – 2–4 weeks (Hochmuth & Sideman, 2023).
  • Autumn and winter varieties (Conference, Bosc, Anjou, Pass‑Crassane) tolerate –1…0 °C well and can be stored from 2 to 6–8 months depending on variety and conditions (Mandal et al., 2021; Hochmuth & Sideman, 2023).

Golden rule: the more stable the temperature, the better. Fluctuations of more than 0.5 °C stimulate respiration and shorten storage life. Avoid frequent opening of the storage in cold weather; if you open it, do so quickly.

Relative Humidity

Pears contain 80–85% water, and during storage they constantly lose moisture through evaporation. If humidity is below 85%, fruits begin to shrivel, lose firmness, and deteriorate in appearance (Westwood, 1993; Hochmuth & Sideman, 2023).

Optimal humidity for pear storage is 90–95%. At this humidity, evaporation is minimal, and fruits remain juicy and firm.

How to maintain high humidity:

  • Use containers with tight‑fitting lids or plastic liners (with small ventilation holes).
  • Regularly moisten the floor and walls of the storage (but do not allow water to accumulate on the fruits!).
  • Place open containers of water in the storage.
  • Avoid draughts that dry the air.

Caution: at humidity above 95% and insufficient ventilation, conditions are created for mould development. Therefore, humidity must be maintained together with good air circulation.

Ventilation and Gas Composition

Pears continue to respire after harvest: they absorb oxygen and release carbon dioxide, as well as ethylene. If there is no ventilation in the storage, the concentration of carbon dioxide and ethylene increases, which can cause physiological disorders (Westwood, 1993; Jackson, 2003).

Ventilation rules:

  • The storage should have natural or forced ventilation that provides air exchange at least 1–2 times per day.
  • It is important that air circulates around the boxes and containers, not just in the aisles. To achieve this, containers are placed on grids or pallets, leaving a gap between boxes and walls.
  • Avoid air stagnation in corners and between stacks – ethylene accumulates there, accelerating ripening.

Additional control (for experienced growers):

For long‑term storage (more than 3 months), controlled atmosphere (CA) can be used. This is a commercial technology, but some elements can be useful in amateur conditions:

  • Reducing oxygen to 2–3% and increasing carbon dioxide to 1–2% significantly slows respiration and ripening (Hochmuth & Sideman, 2023; Jackson, 2003).
  • For winter varieties such as Anjou, Conference, Bosc, recommended CA parameters: 1.5–2.5% O2 and 0.5–2.5% CO2 at –1…0 °C (Mandal et al., 2021).
  • At home, an approximate CA effect can be achieved by placing pears in plastic bags with small holes (but not airtight!) – this creates a microclimate with reduced O2 and increased CO2 that slows ripening.

Important: completely airtight packaging without air access leads to anaerobic respiration, alcoholic odour, and spoilage. Therefore, always allow air access – at least through a few punctures.

Packaging for Storage

Proper packaging protects pears from mechanical damage, moisture loss, and mutual influence.

Types of packaging:

1. Crates (wooden or cardboard) – the most common option. Pears are placed in one or two layers, interleaved with soft paper or dry wood shavings (preferably from hardwoods, resin‑free). Shavings act as cushioning and absorb excess moisture (Potapov et al., 2000).

2. Wrapping each fruit in paper – a classic method for valuable varieties. Use thin but strong paper (parchment, waxed paper). This prevents pressure between fruits, reduces evaporation, and slows the spread of infection (Mandal et al., 2021).

3. Plastic bags or liners – create a microclimate with high humidity and low oxygen, which slows ripening. Important: bags should be open or have punctures (1–2 holes of 5 mm diameter) for gas exchange. Complete sealing leads to spoilage (Westwood, 1993).

4. Plastic containers with lids – convenient for small batches. The lid should have ventilation holes.

Packing principles:

  • Place fruits in rows, but not too tightly – there should be a little space between them for air circulation.
  • The lower layer should not be subjected to pressure from the upper layer – therefore, boxes are filled to no more than 2–3 layers of fruit.
  • Interleave each layer with shavings or paper. Thickness of cushioning 1–2 cm.
  • Place fruits with stems stem‑down or sideways, so they do not damage neighbours.

What to Do with Fruits That Begin to Ripen

Even in the best conditions, some pears may start ripening early. They should be removed from storage in time and either consumed or moved to a cooler place for short‑term storage. Signs of beginning ripening:

  • Slight yellowing of the skin.
  • Development of aroma.
  • Flesh becomes slightly soft to the touch.

Such pears cannot return to their previous state, so use them first.

Approximate Storage Life of Different Varieties (at –1…0 °C and 90–95% humidity)

Variety Group Examples Storage Life
Summer Bartlett, Clapp’s Favorite 2–4 weeks
Autumn Conference, Bosc, Duchess 2–4 months
Winter Anjou, Pass‑Crassane, Winter Williams 4–6 (up to 8) months

(Jackson, 2003; Hochmuth & Sideman, 2023; Mandal et al., 2021)

How Often to Check Stored Pears

  • In the first 2–3 weeks after storage, check every 3–5 days – during this time hidden damage and rot may appear.
  • Thereafter, checking once every 2–3 weeks is sufficient.
  • At each inspection, remove any fruits with signs of rot, softening, or darkening. Do not leave them near healthy ones.
  • Keep a simple log – note inspection dates and conditions to spot trends (e.g., more spoilage in one corner of the storage – means ventilation or temperature is inadequate there).

Summary for the Grower

  • Temperature: –1…0 °C for winter varieties, +1…+2 °C for summer. Avoid fluctuations.
  • Humidity: 90–95%. Do not allow fruits to dry out.
  • Ventilation: ensure air circulation, but without draughts. Remove excess ethylene.
  • Packaging: crates with shavings or paper, wrapping each fruit, plastic bags with holes.
  • Monitor: inspect regularly, remove spoiling fruits.
  • Remember: even under ideal conditions, storage is not endless – plan to use the harvest within the timeframes indicated for your varieties.

6. Causes of Storage Losses

You did everything right: picked on time, harvested carefully, sorted thoroughly, created good conditions. Yet even with the best care, part of the crop may spoil. Storage losses are not just “how it happened.” They always have a specific cause: disease, physiological disorder, or a mistake in storage conditions. Understanding these causes is the first step to reducing losses in the next season (Westwood, 1993; Jackson, 2003).

All storage losses can be divided into three groups:

1. Storage diseases – fungal and bacterial infections.

2. Physiological disorders – metabolic disturbances within the fruit itself.

3. Storage condition violations – errors in temperature, humidity, ventilation.

Storage Diseases

This is the main cause of pear losses during storage. Fungi and bacteria enter the fruit through micro‑cracks, wounds, the stem, or natural openings (lenticels, stomata) and gradually destroy the flesh (Agustí, 2010; Westwood, 1993).

1. Grey Mould (Botrytis cinerea)

Appearance: a soft, watery, light‑brown spot appears on the fruit surface. The spot enlarges rapidly and becomes covered with a grey fluffy mould – this is the fungus’s spores. The smell is sweet‑putrid.

How it enters: the fungus often enters through the flower calyx (top of the fruit) or through wounds. It infects fruits in the orchard but manifests during storage. It develops especially quickly at high humidity and temperatures above 0 °C (Mandal et al., 2021).

Prevention:

  • Thorough sorting – remove fruits with even the slightest suspicion.
  • Ensure quick ventilation and drying of fruits before storage.
  • Prevent condensation on fruits.
  • Maintain temperature around 0 °C – at –1 °C fungal development slows significantly.

2. Blue Mould (Penicillium expansum)

Appearance: a depressed light‑brown spot appears on the skin, then the flesh underneath becomes soft, watery, and a bluish‑green spore mould appears on the surface. The rot quickly penetrates deep into the fruit.

How it enters: through any skin damage – scratches, dents, cracks. Especially often through the site of a torn stem. Infection occurs during harvesting and sorting (Westwood, 1993).

Prevention:

  • Preserve the stem – this is the main protection.
  • Avoid mechanical damage.
  • Cool fruits as quickly as possible after harvest.
  • Store at –1…0 °C.

3. Alternaria Rot (Alternaria spp.)

Appearance: dark, almost black, dry depressed spots on the skin. The flesh under the spots darkens and becomes bitter. Often affects fruits that have been left on the tree for a long time or were harvested overripe (Agustí, 2010).

How it enters: the fungus lives on plant debris and reaches fruits through micro‑cracks or the calyx. It develops at temperatures above +2 °C.

Prevention:

  • Timely harvest – do not allow overripening.
  • Remove fallen leaves and fruits from the orchard.
  • Store at around 0 °C.

4. Phytophthora Rot (Phytophthora spp.)

Appearance: a hard, leathery, dark‑brown spot with irregular edges. The flesh under the spot becomes dense and bitter. Less common than other rots, but can cause serious losses, especially in wet years (Mandal et al., 2021).

How it enters: the fungus spores live in soil and plant debris. They reach fruits through rain or irrigation splashes.

Prevention:

  • Prevent fruit contact with soil.
  • Ensure good canopy ventilation.
  • Control weeds in the tree‑row strips.

Physiological Disorders

These are not diseases, but metabolic disturbances within the fruit itself. Causes – unfavourable growing conditions (drought, waterlogging, nutrient deficiency) or errors during storage. The pear may look healthy externally, but irreversible changes have already begun inside (Westwood, 1993; Jackson, 2003).

1. Scalding (Superficial Scald)

Appearance: brown or yellowish‑brown irregular blotches appear on the skin. The blotches may merge, and the skin becomes wrinkled. The flesh underneath remains healthy, but appearance suffers greatly.

Cause: oxidation of natural compounds in the skin (α‑farnesene) under the action of ethylene. The longer pears are stored, the higher the risk of scald. Winter varieties (Anjou, Bosc, Conference) are particularly susceptible during long storage (Jackson, 2003).

Prevention:

  • Timely harvesting (not too early and not too late).
  • Rapid cooling after harvest.
  • Reducing ethylene concentration in storage (ventilation).
  • For commercial stores – antioxidant treatments.

2. Internal Flesh Browning (Core Browning, Brown Heart)

Appearance: externally the fruit may look normal. When cut, the flesh around the seed cavity is brown, dry or conversely watery. The taste becomes bitter. Often affects large fruits (Mandal et al., 2021).

Cause: most often – calcium deficiency in the fruit or excessively high carbon dioxide concentration in the storage. It can also be caused by too late harvest or high storage temperatures (Westwood, 1993).

Prevention:

  • Balanced tree nutrition – especially with calcium and potassium.
  • Harvest at optimal times.
  • Control gas composition in storage (do not allow CO2 to exceed 2–3%).
  • Do not store very large fruits longer than usual.

3. Freezing Injury (Chilling Injury / Freeze Damage)

Appearance: the skin becomes glassy, with depressed watery areas. After thawing, the flesh becomes soft, watery, and tasteless. With severe freezing – it loses structure completely.

Cause: storage at temperatures below the fruit’s freezing point (below –1.5…–2 °C). Even a short‑term temperature drop can cause damage (Westwood, 1993; Hochmuth & Sideman, 2023).

Prevention:

  • Carefully control storage temperature.
  • Place a thermometer at the coldest point.
  • Do not store pears near products that require lower temperatures.

4. Watery and Glassy Flesh

Appearance: the flesh becomes translucent, glassy, juicy in appearance, but insipid in taste. Often found in large fruits, especially in years with heavy rain before harvest.

Cause: disruption of cell wall structure due to excessive water uptake into the fruits before harvest. Cells rupture, and juice leaks into intercellular spaces (Agustí, 2010).

Prevention:

  • Control irrigation during fruit fill – avoid sharp fluctuations.
  • In rainy summers, harvest 5–7 days earlier than usual.
  • Such fruits are not suitable for long storage – use them first.

5. Cracking

Appearance: longitudinal or transverse cracks appear on the skin, often at the base or along the sides. Cracks dry out or become entry points for rots.

Cause: uneven fruit growth due to alternating dry and wet weather. The skin cannot keep up with the rapidly growing flesh (Mandal et al., 2021).

Prevention:

  • Even irrigation during active fruit growth.
  • Mulching tree‑rows to maintain stable soil moisture.
  • Varieties with thick skin are less prone to cracking.

Storage Condition Violations

Even healthy fruits can spoil if storage parameters are violated. This is often the result of inattention or lack of equipment.

1. Temperature Too High

Consequences:

  • Accelerated respiration and ripening – fruits overripen and become mealy.
  • Rapid disease development – at +5 °C, mould grows 2–3 times faster than at 0 °C (Jackson, 2003).
  • Moisture loss and shrivelling.
  • Development of scald and internal browning.

What to do: check temperature with a thermometer at several points in the storage. Do not rely on “feeling” – the thermometer must be accurate.

2. Humidity Too Low (<85%)

Consequences:

  • Fruits lose water – shrivel, become limp, skin loses gloss.
  • Fruit weight decreases.
  • Taste worsens – sugar concentration increases but the fruit seems less juicy.

What to do: maintain humidity at 90–95%. Install a hygrometer. If humidity is low – place open water containers, moisten the floor, use tight packaging.

3. Humidity Too High (>95%) and Lack of Ventilation

Consequences:

  • Condensation forms on fruits – water droplets on the surface.
  • Condensation creates an ideal environment for grey mould and blue mould.
  • Fruits “suffocate” – carbon dioxide accumulates, alcoholic odour appears.

What to do: ensure air circulation – leave gaps between boxes, do not pack the storage completely full. Ventilate regularly. Do not use completely airtight containers.

4. Ethylene Accumulation

Consequences:

  • Ethylene – the ripening hormone – accelerates all ageing processes (Westwood, 1993).
  • Fruits turn yellow, soften, lose aroma.
  • Increased risk of scald and internal browning.

Sources of ethylene in storage:

  • The pears themselves (especially ripening ones).
  • Apples, bananas, melons – if stored nearby.
  • Overripe or damaged fruits.

What to do:

  • Store pears separately from apples and other ethylene‑producing fruits.
  • Regularly remove overripe and damaged fruits.
  • Ensure ventilation to remove ethylene.
  • For long‑term storage of winter varieties – use exhaust ventilation or install ethylene absorbers (special filters, not always available in amateur conditions, but activated carbon or potassium permanganate in open containers can be used).

5. Mixing Different Varieties and Ripening Groups

Consequences: summer varieties produce more ethylene and accelerate the ripening of winter varieties, shortening their storage life.

What to do: store varieties separately. If that is not possible, at least separate summer and autumn from winter varieties by different boxes and different zones of the storage.

Summary Table of Loss Prevention

Cause of Loss Main Prevention
Fungal diseases Thorough sorting, intact stem, rapid drying and cooling, low temperature
Physiological disorders (scald, browning) Timely harvest, balanced nutrition, good ventilation, control of CO2 and ethylene
Freezing injury Accurate temperature control, do not store at –1.5 °C or lower
Moisture loss High humidity (90–95%), tight packaging, no draughts
Excess ethylene Separate storage from apples, regular removal of overripe fruits, ventilation
Condensation and stagnant air Ventilation, gaps between containers, airing, loose packaging

Summary for the Grower

  • Diseases are the main enemy. They start from wounds and micro‑cracks. Therefore, the best protection is careful harvest, intact stem, and thorough sorting.
  • Physiological disorders are most often related to calcium deficiency, excess ethylene, or improper temperature. Balance nutrition, store at –1…0 °C, and ensure ventilation.
  • Storage condition violations are the result of carelessness. Monitor temperature and humidity with instruments, not “by eye”.
  • Regularly inspect stored pears. Timely removal of one diseased fruit can save the whole batch.
  • Record key parameters and inspection dates – this helps understand where problems arise and adjust conditions for the next season.

References

  1. Agusti, M. (2010). ‘Desarrollo del fruto’, in Fruticultura. Madrid, Spain: Ediciones Mundi-Prensa, pp. 127-148.
  2. Colavita, G.María., Curetti, M., Sosa, M.Cristina., Vita, L.I. (2021). ‘Pear’, in Mandal, D., Wermund, U., Phavaphutanon, L., Cronje, R. (ed.) Temperate Fruits. Production, Processing, and Marketing. Burlington, Canada: Apple Academic Press, pp. 107-182.
  3. Hochmuth, G.J., Sideman, R.G. (2023). ‘Harvesting, Handling, and Storage’, in Knott's Handbook for Vegetable Growers. : John Wiley & Sons, pp. 475-564.
  4. Jackson, J.E. (2003). ‘Eating quality and its retention’, in Biology of Apples and Pears. Cambridge, UK: Cambridge University Press, pp. 341-383.
  5. Westwood, M.Neil. (1993). ‘Crop Maturity’, in Temperate-zone. Pomology. Physiology and Culture. Portland, Oregon: Timber Press, pp. 300-315.
  6. Westwood, M.Neil. (1993). ‘Postharvest Storage and Nutritional Value’, in Temperate-zone. Pomology. Physiology and Culture. Portland, Oregon: Timber Press, pp. 336-363.
  7. Потапов, В.А., Фаустов, В.В., Пильщикова, Ф.Н. (2000). ‘Плодовый сад [Orchard]’, in Плодоводство [Fruit growing]. Москва: Колос, pp. 207-369.
  8. Тарасов, В.М., Фаустов, В.В., Никиточкина, Т.Д. (1981). ‘Определение съемной зрелости плодов [Determining the harvest maturity of fruits]’, in Практикум по плодоводству [Fruit growing workshop]. Москва: Колос, pp. 300-303.
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