Production problems linked to bad weather in Brazil and Vietnam have seen global supplies lagging demand for three years. That has left stocks depleted and driven benchmark ICE exchange prices to a peak of $3.36 per lb.

Last time coffee traded that high was in 1977 when snow destroyed swathes of Brazil's plantations. However, the shock to consumers was much bigger back then. If adjusted for inflation, $3.36 per lb in 1977 would be equivalent to $17.68 today.

Experts are meanwhile predicting yet another year of lacklustre coffee output.

Brazil, which produces nearly half the world's arabica - high-end beans used primarily in roast and ground blends - experienced one of its worst droughts on record this year.

Although rains finally arrived in October, soil moisture remains low and experts say the trees are producing too many leaves and too few of the flowers that turn into cherries.

In Vietnam, which produces some 40% of the robusta beans typically used to make instant coffee, a severe drought earlier this year was followed by excess rains since October.

Consultancy StoneX sees Brazil's arabica output falling 10.5% to 40 million bags next year, offset somewhat by higher robusta output, thus cutting the country's overall crop by 0.5%.

In Vietnam, the crop could shrink up to 10% in the year by the end of September 2025, adding to the global robusta shortage.

WHY ARE TRADERS WORRIED?

Brazil-based traders Atlantica and Cafebras are seeking court-supervised debt restructuring due to coffee price surges, crippling hedging costs and delivery delays.

Court-supervised debt restructuring precedes bankruptcy if the negotiation is not successful.

Traders who buy beans from local suppliers like Atlantica and Cafebras typically take short positions in the futures market to hedge their physical market exposure.

Fearing they might no longer get their physical coffee, many traders are closing out what have become loss-making short futures positions.

Closing out short positions involves buying or going long futures, which in turn drives prices even higher.

Higher futures prices then push up margin calls or downpayments that traders are required to pay to protect against trading losses, thereby creating more stress in the industry.

IMPACT ON ROASTERS AND CONSUMERS

Surging coffee prices are a problem for roasters.

The boss of Nestle, the world's biggest coffee firm, was ousted earlier this year after the board grew unhappy about weak sales and a loss of market share due to price rises, which prompted consumers to switch to cheaper brands.

Roasters tend to buy coffee many months in advance, which means consumers will likely see the price spike in 6 to 12 months.

Consumers who drink out will feel less of a pinch of today's rising prices.

Roasters like Starbucks (SBUX.O) that sell mostly to cafes should fare better as the global coffee price accounts for only about 1.4% of the total price of a typical $5 cup of coffee in a cafe.