MAX31865 - can I use a 150 ohm Rref?
It's a 15 bit ADC with a resolution of 0.03125°C. Even if you only used one-sixteenth of the range you'd still get a resolution of about 0.5 °C and for beer making that's plenty close enough. Plus, consider what the RTD accuracy is?

Anyway, the data sheet says that bias voltage output current is 5.75 mA maximum and given the bias voltage is 2.06 volts maximum, that means the resistor can be no less than 358.3 ohms under the worst case scenario.