I make ice cream the old-fashioned way with rock salt and ice packed around the canister. Like all kitchen experiments, I’ve had successes — such as my decadent dark chocolate peanut butter — and failures — most recently a salted caramel that was bafflingly savory. Trust me, a caramel that lacks sweetness is not something you want to try. First time we’ve ever thrown away homemade ice cream.

One of the glorious things about well-made, homemade ice cream is how rich and thick it is. Upon researching I’ve discovered the reason behind this is the air content in the ice cream.

Two scoops of ice cream on metal scoops, one chocolate with peanut butter swirl and one caramel

The industry calls it overrun — the volume of air whipped into the mix during freezing. At the regular end of the shelf, overrun is close to 100%, meaning roughly half of what you’re scooping is air, with as little as 10% butterfat, the FDA floor for calling it ice cream at all. Premium brands keep overrun under 50% and push butterfat to 14–16%. Some super-premium pints get overrun down to 15–20%. Less air leaves more room in the carton for the thing you’re actually paying for. It’s a real, measurable number, and it’s nowhere on the label.

I started thinking about overrun again recently — not because of anything happening in my kitchen, but because it’s such a good model for a mistake that shows up constantly in private equity: mistaking the appearance of substance for the thing itself.

Overrun: the difference between margin and air

Many consumer brands that come up for sale tell a similar story: flat or declining performance for a while, then an upturn right before the deal gets marketed. Sometimes the company has done the hard work of expanding the right distribution, increasing productive marketing spend, enforcing pricing guardrails, etc. And sometimes it’s the business equivalent of whipping in air: discounts deepened, trade spend pulled forward, a sales push timed to make this year’s number look good regardless of what happens next year. Both produce the same chart, but one business is healthy and the other just appears so.

That’s overrun, applied to a business case instead of an ice cream carton. The easy move for a buyer is to take the story at face value and underwrite straight off the trendline and assume the recent improvement is the new baseline to project growth against. The harder and more valuable move is the opposite one: figure out how much of any reported turnaround is genuine repositioning and how much is air, whipped in to make the last year or two look good before a sale. The diligence job is separating the butterfat from the air. One of the challenges of Private Equity deals is that too many take a seller’s turnaround story at face value, scoping up the positive spin, instead of comprehensively weighing it first.

Ice crystals: short-term “solves” lead to long-term damage

Ice cream’s texture comes down to crystal size, and crystal size comes down to speed and attention. Freeze it fast, with constant agitation, and you get many small crystals competing for the same water molecules, nothing has room to grow, and the result is smooth. Let the temperature drift — a freezer door left open, a truck that isn’t cold enough — and the ice partially melts and refreezes onto the crystals already there. They grow and the texture turns grainy.

A long, slow erosion in a brand’s performance is another example of temperature drift. When there is high pressure to achieve sales targets, management teams make decisions that prioritize the short term over the long term. I’ve seen this vicious cycle time and time again: there is no organic path to the ambitious sales targets, prices are discounted, customers and consumers learn to only buy at the lower prices, margins erode, costs and quality are cut to match the new lower price, brand quality declines, sales targets still cannot be met. Each decision opens and closes that freezer door again, growing more and more ice crystals.

Stabilizers: strong structures support healthy growth

Many commercial ice cream makers don’t leave texture to luck. They add stabilizers, such as xanthan gum, tapioca, and gelatin, which act as thickeners to slow the movement of water molecules and keep crystals from recrystallizing even when storage conditions aren’t perfect.

A brand being transitioned to a new owner also needs commercial stabilizers:

Pressure-test every point of share gain. Separate the healthy distribution and volume gains from dumping in accounts that won’t turn, big drops that will sit in warehouses and backrooms for months, and price cuts that must be lapped.
Build future state Route-to-Market. Commercial performance rests on relationships that don’t automatically survive an ownership change; know what your ideal future state RTM looks like and negotiate favorable positioning.
Perform portfolio prioritization. Analyze each SKU and brand to determine where to prioritize and where to discontinue. The trade-offs between volume and focus are tough, but critical for sustainable growth.
Set planning cadences and processes. Commercial planning processes and cadences are invaluable stabilizers that enable transformative growth.
Stabilize management teams. Leadership changes are inevitable during transitions, and can bring the necessary new thinking and energy, but a revolving (freezer) door of leaders is massively destabilizing for the business and can create irreparable damage.

How much air does the business you have your eye on have whipped into its results?

Blade Advisory helps private equity firms and their portfolio companies perform due diligence and develop portfolio strategies, route-to-market, and planning cadences.