Does Soaking Hay Reduce Sugar? Best Times and its Benefits

Yes — soaking hay does reduce sugar. Submerging hay in water pulls out a meaningful portion of its water-soluble carbohydrates (WSC), which include fructans, glucose, fructose, and sucrose.

But how much sugar comes out depends heavily on soak time, water temperature, and the type of hay you're starting with — anywhere from about 5% to over 50% reduction.

For Canadian horse owners, this question isn't academic. Between metabolic horses navigating our long winters on stored forage, senior horses with worn teeth, and the sheer variability of hay grown across the Prairies, knowing exactly how soaking works and where it falls short can make a real difference to your horse's health.

This guide breaks down the science, the timing, and the best practices, so you can soak hay with confidence instead of guesswork.

Key Takeaways

• Soaking reduces WSC/sugar by roughly 5% to 54%, depending on how long the hay soaks.
• Longer soaks (up to 16 hours) remove more sugar but cause greater nutrient loss and a sharp rise in bacterial growth.
• 15–60 minutes is the commonly recommended window for most horses, balancing sugar reduction against nutrient and hygiene concerns.
• Soaking is a management tool, not a guarantee it doesn't confirm a hay is low-sugar enough for insulin-resistant or laminitic horses. Only a hay analysis can do that.

Why Do You Soak Hay for Horses?

Fresh pasture grass is roughly 80% water, while dried hay is typically only 10–20% moisture. Soaking brings some of that hydration back, and along the way it accomplishes several things at once:

 

• Reduces sugar (WSC) for horses with metabolic conditions.
• Reduces dust and airborne particles for horses with respiratory sensitivities.
• Softens hay for horses with poor dentition, making it easier to chew.
• Increases water intake, which can help hydration in horses that are reluctant drinkers, particularly in a Canadian winter when cold water intake often drops.

Does Soaking Hay Reduce Sugar? 

Soaking hay helps reduce its water-soluble carbohydrates (WSC), including fructans, glucose, fructose, and sucrose. These sugars dissolve into the water while the hay is soaking.

Research summarized by Veterinary Partner and KER Equinews shows that sugar reduction increases with soaking time, but the exact amount varies by the forage and how it is soaked.

In general, the longer hay stays underwater, the more sugar it loses. However, sugar reduction is not always predictable. It depends on the type of hay and its original sugar content before soaking.

Research shows that soaking can lower sugar levels, but soaking alone does not guarantee that hay will be safe for every horse. Testing the hay is still the most reliable way to know its sugar content.

What Does This Mean for Horse Owners?

Research suggests that soaking hay can reduce sugar, but the results are different for every type of hay.

• A 15–60 minute soak may remove some sugar from certain hays.
• A 1-hour cold soak reduces sugar by about 12% on average.
• An overnight (16-hour) soak can reduce sugar by around 30%, but it also washes away more nutrients and increases the risk of bacterial growth.
• The best way to know if hay is safe for horses with laminitis, EMS, or insulin resistance is to test the hay. Experts generally recommend choosing hay that contains less than 10% NSC instead of relying only on soaking.

Takeaway: Soaking is a proven, effective way to pull sugar out of hay, but the exact percentage depends on soak duration, water temperature, and the hay itself. There's no single number that applies to every bale.

Which Horses Benefit From Soaked Hay?

Soaking Hay for Insulin-Resistant Horses

Soaking Hay for Laminitic Horses

Laminitis and founder are closely linked to spikes in blood insulin, which are in turn driven by high-carbohydrate intake. For these horses, soaking is often combined with — not a replacement for — sourcing hay that has already tested low in sugar and starch.

Soaking Hay for Senior Horses:

For senior horses with worn or missing teeth, soaked hay is softer and considerably easier to chew, which helps reduce the risk of choke and impaction. Soaking also boosts water content at a time when older horses, particularly through a Canadian winter, may not be drinking enough on their own.

Other Conditions That May Benefit From Soaked Hay

• PSSM (Polysaccharide Storage Myopathy)
• RER (Recurrent Exertional Rhabdomyolysis)
• HYPP, where potassium reduction is a priority
• COPD/heaves and other respiratory conditions (dust reduction)
• Weight management and calorie-restricted diets

Benefits of Soaking Hay for Horses

• Reduces sugar/NSC — the primary benefit for metabolic horses, discussed above.
• Increases water intake and hydration.
• Reduces dust and airborne particles, supporting respiratory horses — though it's worth noting that steaming is generally considered more effective specifically for dust and mould reduction, with soaking being the stronger tool for sugar reduction (see the comparison table below).
• Allows more forage volume to be fed safely in calorie-restricted diets, which helps extend chew time and can reduce the risk of ulcers and stereotypic behaviours like cribbing.
• Easier digestion and reduced choke/impaction risk, especially for seniors.

How to Soak Hay: Step-by-Step Guide

1. Fill a hay net or loose-fill the hay directly into a clean bin, tote, or trough.
2. Fully submerge the hay, making sure water covers it completely.
3. Soak for your recommended time (see the chart below).
4. Remove the hay and let it drain for at least 30 minutes before feeding.
5. Feed promptly, and discard the soak water responsibly rather than letting it pool near grazing areas or water sources.

Equipment options range from a simple hay net dropped in a stock tank to purpose-built hay-soaking tubs, which make draining and cleanup considerably easier if you're soaking regularly through a Canadian winter.

How Long to Soak Hay

 

General rule of thumb: aim for about 30 minutes in warm or hot water, or 60 minutes in cold water, for a good balance of sugar reduction and safety.

How Long to Soak Hay for Laminitis or a Laminitic Pony

For laminitic or insulin-resistant horses, shorter, controlled soaks of 15–60 minutes combined with an actual hay analysis are a safer strategy than relying on a long overnight soak alone. Hay intended for these horses should ideally already test below 10% non-structural carbohydrate; soaking is a safeguard, not a substitute for knowing what's in your hay.

How Long to Soak Hay Cubes

Hay cubes soak faster than loose flakes or full bales because of their compressed surface area typically 10–20 minutes, or per the manufacturer's instructions, until softened through.

Factors That Affect Sugar Reduction In Hay

Soak Time

There's a direct relationship between soak time and sugar removal, but it comes with diminishing returns and rising risk. The biggest gains happen in the first hour; after that, you're trading marginal sugar reduction for real nutrient loss and bacterial growth.

Water Temperature

Warm or hot water pulls sugar out of hay faster than cold water. As a practical guideline, a 30-minute soak in hot water can achieve results similar to a 60-minute soak in cold water — useful to know if you're soaking hay outside through an Alberta or Saskatchewan winter, when "warm" water is a genuine luxury.

Type of Hay

• Grass hays — like timothy, orchardgrass, and fescue — generally carry higher WSC/fructan levels and tend to benefit more noticeably from soaking.
• Legume hays like alfalfa are typically already lower in NSC, often already under 10%, and usually don't require soaking at all.
• Compressed flakes vs. loose, fluffed hay soak differently because of surface area — loose hay tends to release sugar faster than a tightly packed flake.

If you're trying to decide between forage types in the first place, our guide on Timothy Hay vs. Alfalfa Hay for Horses in Canada breaks down the nutritional differences in more detail, and our Low Sugar Hay for Horses: What Canadian Owners Should Know article goes deeper into NSC targets specifically.

Important Tips for Soaking

1. Discard the water. Never reuse soak water — it now contains leached sugars, minerals, and bacteria. Dispose of it away from grazing areas and natural water sources.
2. Rinse the hay. A brief clean-water rinse after draining can help remove surface residue and mould spores.
3. Keep equipment clean. Scrub bins and nets between uses so bacteria from one batch doesn't carry over into the next.

Best Practices for Soaking Hay for Horses

Water Temperature

Warm water speeds up sugar extraction, while cold water works more slowly but is still effective and it's generally safer in warmer weather since it slows bacterial growth compared to a warm soak sitting out.

Nutrient Loss

Soaking beyond 60 minutes starts to leach meaningful amounts of potassium, calcium, phosphorus, magnesium, digestible fibre, and soluble protein. If you're soaking hay long-term as part of a management plan, it's worth adding a vitamin/mineral supplement or ration balancer to make up the difference — ideally with input from an equine nutritionist.

Hygiene

Always use clean water and clean containers, and feed soaked hay soon after removing it from the water rather than letting it sit around.

Disadvantages of Soaking Hay

Soaking isn't a free lunch, and it's worth understanding the trade-offs before you build it into your routine:

• No guarantee of suitability. Soaking doesn't confirm a hay is safe for horses needing under 10% HC (insulin-resistant, PSSM horses). Only a lab hay analysis can confirm actual sugar content.
• Nutrient loss. Macrominerals (potassium, calcium, phosphorus, magnesium), digestible fibre, and soluble protein all decline with soaking. Capping soak time at 30–60 minutes, unless a nutritionist advises otherwise, helps limit this.
• Bacterial growth. Research has found bacterial counts can rise by roughly 50% after just a 10-minute soak, and by as much as 500% after a 9-hour soak. Clean water, clean containers, short soak times, and prompt feeding all help manage this risk.
• Environmental concerns. Soaking requires large volumes of water, and the resulting runoff needs to be disposed of properly, away from grazing areas and water sources — a real consideration for rural Canadian properties on well water or septic systems.
• Labour intensive. Filling, draining, and moving wet hay (which is considerably heavier than dry hay) takes real time and effort, especially in winter.
• Added cost. Between water usage and equipment, soaking does add expense, though it's typically far less than investing in a hay steamer setup.

Can Soaking Hay Increase Bacteria?

Yes. Studies have found bacterial counts rising by around 50% after a 10-minute soak and by as much as 500% after a 9-hour soak. You can mitigate this by using clean water and containers, keeping soak times short, and feeding the hay promptly after draining rather than letting it sit.

Does Soaking Hay Remove Nutrients?

Yes. Along with WSC/sugar, soaking also removes potassium, calcium, phosphorus, magnesium, digestible fibre, and soluble protein and the longer the soak, the greater the loss. If soaked hay makes up a significant part of your horse's diet, a ration balancer or targeted supplement can help offset these losses.

What Is the Difference Between Steaming and Soaking Hay?

If dust and respiratory health are your main concern rather than sugar content, steaming may actually serve your horse better than soaking — the two tools solve different problems.

Conclusion

So, does soaking hay reduce sugar? Yes  meaningfully, but variably, with reductions ranging anywhere from about 5% to 54% depending on soak time, water temperature, and hay type.

For most horses, soaking for 15–60 minutes in warm water strikes a reasonable balance between sugar reduction, nutrient retention, and hygiene.

For insulin-resistant or laminitic horses, soaking should be paired with an actual hay analysis rather than relied on alone — sugar content varies too much from bale to bale, and even from field to field, to guess.

If you're feeding a metabolic horse, an aging senior, or simply want to know exactly what's in the hay you're buying, a forage analysis is one of the best investments you can make.

At Horse Creek Hay & Feed, we help horse owners across Alberta find the right hay for their horses. If your horse needs a lower-sugar diet, we can recommend hay options that naturally contain less sugar.

We also suggest getting your hay tested or working with an equine nutritionist to create a feeding plan that's tailored to your horse's health and nutritional needs instead of using a one-size-fits-all soaking method.And if you need hay for your horse then contact us.

For more on choosing the right forage for your horse, check out our related guides on Round Bales vs. Small Square Bales for Horses, Orchard Grass vs. Timothy Hay for Horses, and 7 Signs You're Buying Bad Hay.