Thermo-ageing, a process otherwise known as baking, roasting or its scientific name torrefaction, involves heating wood to a high temperature to remove moisture, resin and other volatiles. Acoustic guitars that undergo thermo-ageing develop changes to their appearance, sound, weight and resilience.
Some modern electric guitars such as Music Man’s Stingray and Cutlass ranges boast roasted maple necks. Maple is naturally light in colour, but the necks on these guitars are a much deeper, darker brown. Thermo-ageing for an acoustic guitar yields even stronger results because of the more apparent effect that wood has on an acoustic’s tone.
Effects on a thermo-aged guitar
Molecules stiffen during torrefaction, providing powerful resonance and a quicker strumming response. Roasted woods have an expansive EQ range and full sustain. They’re even louder and project more than their non-aged equivalents across the frequency spectrum, but especially in bass and treble.
An acoustic guitar is less susceptible to atmospheric effects following torrefaction. Acoustics require a slight amount of moisture to remain in good condition. It doesn’t quite mean you have to throw a bucket of water of your guitar, but keeping it out of excessively hot or cold places and avoiding drastic temperature changes will allow it to age much more consistently. When a guitar dries out, the wood contracts and cracks may start to appear from the glue working overtime to hold it together.
Why would you want one?
The torrefaction treatment fast-forwards the natural ageing process of wood. It can’t improve bad pieces of wood, but it does bring out vintage properties in good cuts. Valued old acoustics are extremely sought after because they become chemically balanced and more stable over a long period of time. So if you’re on the hunt for a retro guitar tone but aren’t prepared to fork out for vintage prices, roasted guitars are an excellent option.
There’s plenty of choice too. Several tonewoods are capable of torrefaction such as maple, mahogany and spruce. It’s still possible to get varying tones after the process has been completed. However only choice-selected and seasoned woods can undergo it.
Ibanez are one of the latest guitar builders to take on the roasting challenge. Despite being obviously well-known for their electric guitars, they’ve boldly released a thermo-aged line of acoustics all well under £1000.
The range features a host of thermo-aged choices. You can get your hands on a number of spruces and mahoganies, in combination with X bracing that further boosts volume. They say some of the guitars are ‘open pore’ which refers to the satin raw finish, but in fact, they tighten up through treatment.
Popular brands
Most heavyweight acoustic companies such as Gibson, Taylor, Martin and Takamine have used baking to great effect. Many custom shop and high-end acoustics are baked because it’s a proven scientific process that heightens the properties of wood – and if you’re paying lots of money for a guitar, you’ll be expecting the very best.
You’ll be looking at £2000 upwards for these guitars. Check out Gibson’s 2019 Montana range to get an idea of specs and style. They’ve been pioneering it in the Vintage series of guitars for years. Taylor’s 600 Series is also a perfect example of torrefaction taking a guitar to the next level of brilliance.
The likes of Yamaha, Ibanez and Takamine, however, produce excellent thermo-aged guitars at a significantly reduced price in comparison. To be able to get your hands on a mid-range guitar with such a defining feature found in custom guitars is a testament to the market offering progressively better specs at similar prices.
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