Por que não usar uma colher de metal com massa fermentada?

Por que não usar uma colher de metal com massa fermentada? Desmascarando os mitos e entendendo os fatos

If you're a sourdough beginner, you might have heard the advice: “Never use a metal spoon with your fermento natural!” This warning seems to pop up frequently in sourdough circles, blogs, and recipe books, (this is something my mum said to me when I first started baking sourdough) often without much explanation. But is there really any truth to it? As someone who's spent years nurturing sourdough starters, experimenting with different tools, and learning from trial and error, I'm here to shed some light on this topic. Let's dig into the facts and bust some myths about using metal with sourdough.

De onde surgiu essa ideia?

The idea that you shouldn't use metal utensils with fermento natural provavelmente decorre de preocupações sobre a interação entre o metal e o ambiente ácido do starter. Entradas de fermento natural são naturalmente ácidos devido às bactérias do ácido láctico que ajudam a fermentar a mistura de farinha e água, criando o sabor picante característico de pão de fermento natural.
Traditionally, it was thought that the acidity in the starter could react with certain metals, potentially affecting the starter's health or flavor. This advice has been passed down through generations, and like many things in the baking world, it's become a common “rule” without much scientific backing. But does this rule hold up today?

A ciência por trás do metal e da acidez

Let's break down the facts: Sourdough starter is indeed slightly acidic, usually with a pH between 3.5 and 4.5. This acidity is strong enough to preserve the starter and give the bread its unique taste, but it's not potent enough to significantly corrode most metals in the short time that utensils are in contact with it.

• Metais reativos: Metais como alumínio, cobre e zinco são considerados reativos, o que significa que podem corroer ou reagir quimicamente quando expostos a ambientes ácidos. Essa reação pode potencialmente lixiviar sabores metálicos em seu starter, embora isso normalmente exija contato prolongado.
• Metais não reativos: Stainless steel, on the other hand, is a non-reactive metal, meaning it resists corrosion and doesn't react easily with acidic foods. Most modern kitchen tools, including spoons and bowls, are made from stainless steel because it's durable, safe, and easy to clean.

O mito desmascarado: usando aço inoxidável com fermento natural

In my experience, and backed by scientific understanding, using a stainless steel spoon, whisk, or bowl with your sourdough starter is perfectly fine. The brief contact between stainless steel and your starter is not enough to affect the starter's health, the bread's flavor, or the integrity of your equipment.
I've mixed, stirred, and even made pão de fermento natural in steel bowls without any issues. The key is ensuring the metal is non-reactive, like stainless steel, which doesn't interact with the acidity of the starter. Here's why stainless steel is safe:

• Durabilidade: Aço inoxidável is tough and won't chip or crack like some other materials. It's great for mixing and can handle the acidic environment of a sourdough starter without any problems.
• Natureza não reativa: Unlike aluminum or copper, stainless steel doesn't react with acidic foods, so it won't alter the taste of your sourdough or harm the starter's microbial balance.
• Facilidade de limpeza: O aço inoxidável é fácil de limpar e higienizar, reduzindo o risco de bactérias indesejadas contaminarem seu starter.

Quando evitar utensílios de metal

While stainless steel is safe, it's still a good idea to avoid prolonged exposure of your sourdough starter to reactive metals like aluminum, copper, or unlined cast iron, as mentioned above. Here's why:

• Mudanças de sabor e cor: Metais reativos podem conferir um sabor metálico ou alterar a cor do fermento e da massa, especialmente com contato prolongado.
• Possível contaminação: Over time, reactive metals can leach into acidic foods, which isn't ideal, especially when working with a living culture like sourdough.
  For example, storing your starter in a copper bowl or constantly stirring it with an aluminum spoon isn't advisable, as these materials can corrode and affect your starter's quality.

Melhores ferramentas para massa fermentada: minhas recomendações

While you don't have to avoid metal entirely, here are some of the best tools I recommend using with sourdough:

1. Tigelas de vidro ou cerâmica: These are non-reactive, easy to clean, and perfect for storing your starter long-term. Plus, they allow you to see your starter's activity clearly.
2. Stainless Steel Spoons and Whisks: Great for mixing and feeding your starter. The brief contact is harmless, and they're sturdy enough to handle frequent use.
3. Utensílios de madeira ou silicone: Essas são minhas escolhas preferidas. Colheres de madeira são gentis, e o silicone é durável e não reativo, tornando-as ideais para mexer com frequência.
4. Recipientes de plástico ou silicone: Para armazenar seu fermento na geladeira, recipientes de plástico ou silicone funcionam bem, pois não são reativos e vêm com tampas herméticas para manter seu fermento seguro.

Pensamentos finais

The warning against using metal with sourdough is one of those old-school baking myths that has persisted over time. However, the truth is that modern stainless steel utensils are perfectly safe to use with your starter. The brief interaction won't harm your starter or affect your bread in any noticeable way.

Ultimately, it's about using the right kind of metal and ensuring that your sourdough is getting the care it needs-consistent feedings, a clean environment, and the right temperature. So, the next time you reach for that stainless steel spoon, go ahead and stir with confidence!

If you're curious to learn more about sourdough, from beginner tips to advanced techniques, be sure to check out our pão de tomate seco receita, compota de cereja com fermento natural pão, queijo jalapeño sourdough, ou nosso pão de fermento natural clássico receita, juntamente com artigos sobre noções básicas de fermento natural.